ARP 2500 Éliane Radigue Tribute Feat: OMBIENT- The sounds from this machine are amazing!

Born in Paris in 1932, Éliane Radigue spent a large segment of her life concentrating on creating compositions exclusively on the legendary ARP 2500 modular synthesizer.

Electronic musician, OMBIENT, shares an Éliane-influenced performance on our ARP 2500 from a recent visit.

For more intel on the EMEAPP ARP 2500 system, check out this article. Even juicier, here is a video of electronic music pioneer, DON SLEPIAN, giving a tour of our rig.

This is a great interview video where Éliane takes her personal ARP 2500 out for a spin. Between this video and the OMBIENT video above, you can clearly hear the ARP’s “sonic fingerprint”

Check out this current, well-written article on Éliane Radigue at 90 years old, originally published in The New York Times.

For a Composer at 90, There’s Nothing but Time

For decades, Éliane Radigue has created a great deal of slow, very minimal, mostly electronic music.

The composer Éliane Radigue worked with various synthesizers before settling on the ARP 2500, the modular device that would define her sound for years.
The composer Éliane Radigue worked with various synthesizers before settling on the ARP 2500, the modular device that would define her sound for years. Credit…Fondation A.R.M.A.N./Yves Arman

By Hugh Morris Feb. 4, 2022

Éliane Radigue lives and works in a second-floor apartment in the Montparnasse neighborhood of Paris. A weeping fig tree looms above her head; across the loft-like room are three large windows adorned with house plants. The windows face a school across the street which, she wrote in a recent email, “gives its rhythm to days, weeks and months.”

She has lived there for the past 50 years, steadfastly writing a great deal of slow, very minimal, mostly electronic music. The work of Radigue, who turned 90 on Jan. 24, often seems static on first hearing. Her most famous piece, the Buddhism-inspired “Trilogie de la Mort,” lasts three hours and seems vast and empty. Yet zoom in on the musical material and you will find that each line is inching its way along, however deliberately.

“Time, silence and space are the main factors constituting my music,” she wrote in an interview conducted over a series of emails. “Shivering space, like a soft breath, induces the vibrations of the silence slightly, becoming sound.”

She added that “this natural way of working — slowness — takes a long time, of course,” and that she works “inside of time.”

Her music, though, can feel less inside than outside time. In its commitment to letting its ideas grow organically, she often makes you forget that time exists.

Radigue was born in Paris in 1932. She studied the piano from an early age and remembers attending classical concerts on Saturday afternoons. But although the spirit of slow symphonic movements lingers in her work, only rarely does such a style explicitly appear; the opening of “Opus 17,” in which she gradually deconstructs a phrase from Chopin, is an outlier. Most of her other nods to the standard history of classical music — as in “Kyema,” from the “Trilogie,” and a half an hour into “L’Île Re-Sonante” — appear faintly, like a stranger down the road whose shouts are lost in the wind.

More than music per se, it was noise that spoke to Radigue. In the mid-1950s, she lived with her young family next to an airport in Nice. It was while listening to planes fly overhead that she first heard a radio broadcast of Pierre Schaeffer’s “Étude aux Chemins de Fer,” a noise collage based on recordings of trains that formed the first part of Schaeffer’s seminal “Cinq Études de Bruits.” This was among the earliest examples of musique concrète, which uses recorded sounds as base material, manipulating them using electronic techniques.

It was a moment of clarity for Radigue. “Of course it’s music,” she said in 2019. “Everything can become music. It depends on the way we listen to it.”

Radigue in 2011, by which point she had moved into writing for acoustic instruments.
Radigue in 2011, by which point she had moved into writing for acoustic instruments. Credit… Aude Paget/INA, via Getty Images

Radigue contacted Schaeffer, eventually securing a position at the Studio d’Essai in Paris, which he had founded as a Resistance center during World War II and which after the conflict became a kind of experimental music institute. There, she cut and spliced magnetic tape being used by Schaeffer and another composer, Pierre Henry. It was painstaking work, the financial and artistic recognition was negligible and men dominated.

“It was the way everywhere at that time,” she said in the interview. “I didn’t pay any attention to that. No time to waste at that. I just ignored it and made my path anyway.”

But, she added, “it was pleasant to discover a kind of different way in the U.S.A.” Radigue first traveled to the United States in 1964, for an extended stay with her husband at the time, Arman, a well-known painter. (Their son was named after Arman’s best friend, the artist Yves Klein.) She returned to America in the early 1970s, falling in with a bohemian crowd.

“I came to know all the richness of the American artists of this period, both from the Pop Art scene and musicians,” she said. “James Tenney was a close friend, and introduced me to the musicians at this period” — including John Cage, Philip Glass, Steve Reich, David Tudor and Laurie Spiegel. She took in the epically long SoHo loft performances of the era.

It was in America that Radigue began experimenting with synthesizers, having left behind Schaeffer and Henry, who didn’t approve of the “non-concrète” path their assistant’s music was taking. Rather than manipulating recorded sounds, Radigue was more intrigued by electronic feedback — a precarious and time-consuming process to capture, especially as she became focused on controlling minute changes. Radigue worked with various synthesizers, including the Moog and the Buchla 100, before settling on the ARP 2500, the modular device that would define her sound for the next 30 years.

Radigue even named her ARP: Jules. “What touched me the most was ‘his voice,’” she said in the interview. “It was so rich and expressive. Even though, when we disagreed …”

With Jules, there was an appealing ease of use, with sliding matrix switches enhancing her music’s tactile sensitivity, which she explored further once she returned to Paris, having divorced Arman in 1967. “Psi 847” and “Transamorem — Transmortem,” which both premiered in art galleries, have timbral shifts and intermittent rhythmic events that intensify already immersive atmospheres.

At 90, Radigue is slowing down her output. But her career epitomizes committed artistry: a composer who stumbled on a sound and has spent a lifetime nurturing it.
At 90, Radigue is slowing down her output. But her career epitomizes committed artistry: a composer who stumbled on a sound and has spent a lifetime nurturing it. Credit…Fondation A.R.M.A.N./Yves Arman

In the 1970s, she embraced Tibetan Buddhism, abandoning music entirely for three years. When she returned to composing, the incorporation of Buddhist ideas — as in the “Songs of Milarepa” and the sprawling “Trilogie,” influenced by the Tibetan Book of the Dead — only redoubled her work’s simple, seamless construction. “Kyema,” subtitled “Intermediate States,” is particularly evocative; following the Book of the Dead’s journey of existential continuity, it avoids finality, meandering slowly and sustained by throbs, overtone-like blemishes and grainy white noise.

It was only when Radigue was in her 60s that she began to receive recognition in France, and it was even later when she earned a living from her music. An unforeseen shift occurred in 2001. For years, Radigue’s sole collaborator had been her cat. Then, with some reluctance, she accepted her first acoustic commission — “Elemental II,” for the musician Kasper T. Toeplitz — and began collaborating more regularly with performers, including on a release with the laptop quartet the Lappetites. Over the past 20 years, collaboration has brought new works tumbling forth; a decade ago, a composition for solo harp, “Occam I,” initiated an enormous cycle of “Occam” works.

The huge “Occam” collection has brought a new philosophy to the fore in her work, derived from Occam’s razor, which declares that “entities should not be multiplied unnecessarily.” That principle of parsimony is a useful way to understand how this defiantly slow recent music comes together: Instead of the piece enacting a process of distillation, it now starts with material that is already incredibly distilled.

For the listener, the newer work is still made of the same building blocks as her music has had for decades: slow-moving fundamentals, shimmering harmonics, microtones and long spans of material. The only real change is that a few more people now share the process of conception and realization.

In the interview, she said that this late-career blossoming was fading. “It’s difficult now,” she wrote. “I’m quite old, with some health troubles, and I have to reduce my activities.”

But any slowing in her output cannot diminish a career that epitomizes committed artistry: a composer who stumbled on a sound and has spent a lifetime nurturing it. A version of this article appears in print on Feb. 5, 2022, Section C, Page 6 of the New York edition with the headline: Éliane Radigue’s Sounds of Silence. 


Watkins COPICAT- Find out more about the LOOP

In 1958, a new type of echo unit was released and it changed the game overnight. EMEAPP Creative Contributor, Norm Leete, brought us this tasty article that looks back into the sweet spot of tape echo history. The accompanying photos are of three originals from our vast collection of electromagnetic echo units.

The Copicat: In Search of a Portable Echo

By Norm Leete

  The vision for the Copicat evolved from a long history of recording experimentation. The late 1800s and early 1900s saw a flurry of effort to record the human voice. Initial successes involved the progressively advancing use of magnetized wire recording. This involved moving a linear magnetic medium, generally thin piano wire, past a recording head at a constant speed. However, the total game-changer came about in the late 1940s with 3M’s development of cellulose-backed tape that we use today. That, in turn, gave rise to tape recorders of the sort we see now.

  The typical professional audio tape recorder of the early 1950’s used the new 1/4 inch wide tape on 10.5 inch reels that had the capacity to hold 2400 ft of tape. The speed was usually 15 ips which allowed for 30 minutes of recording time. Early professional machines used single-track heads, but half-track heads soon became popular. It was especially desirable for home use as it allowed the tape to be turned over and used in both directions. Tape reels were made from metal or transparent plastic. Standard tape speeds varied by factors of two. 15 and 30 ips were used for professional audio recording, while 7.5 ips and 3 and 3/4 ips were preferred for audiophile and consumer recordings. Typically 7 inch reels were used. 15/16 and 1 and 7/8 ips were the norm for dictation and other applications where lengthy recording times were needed, but lesser-quality was acceptable. Smaller-sized spools were often used in these situations.

Watkins Copicat Mk II, EMEAPP’s earliest Copicat echo unit

  Most machines of this era used separate record and playback heads so it was possible to monitor the recording in a slightly delayed fashion as it was being made. Different electrical routings and alternative placement of the record and playback heads would yield different sonic results. The most popular of these was artificial echo. This effect was first used by Les Paul who, with Bing Crosby’s financial support, created a system that became a key historical component of audio production that continues to this day.

  The need arose to create a standalone unit that would be both portable and simple to use. The fifties saw various efforts to make this a reality. There were amplifiers that had the tape mechanism built-in and, in 1953, Binson’s first Echorec was developed. It used a magnetic disk to create a standalone echo machine.

  In 1958, Watkins (a.k.a. WEM) created the Copicat. The inventor, Charlie Watkins, had a London music shop. He had noticed that a local studio was chaining together various tape echoes to create the desired effect. Watkins decided to create an effect unit that put everything into a single, easy-to-use box. He called it a Copicat. The Shadows used an early Copicat on a track called Apache. The song became a major hit and, suddenly,  everyone wanted one. The urban legend is that the first 100 units sold out instantly with people queueing up down the street to get their hands on a Copicat.

  The first version of the Copicat had a simple tape loop that was held in place by a spring-activated tension arm which eliminated the need for a pinch wheel. It had a record head and 3 playback heads that were controlled by a rotary switch to permit 3 different delay lengths. The unit had 2 inputs. There was no need for an erase head as a permanent magnet in the tension arm performed that function.

  In 1960 the Copicat Mk1 officially went on sale and was soon followed by the Mk2. It had tubes, specifically the 6br8 and 2 ecc83’s. It had a tape loop, a record head, and 3 playback heads each of which had a selection switch and 2 inputs. The erase function remained the same. It was housed in a split top case in which the top part covered the tape loop, and the bottom half covered the controls. It came in a variety of color combinations.

Our 1963 WEM Copycat packed up and ready to roll

  In 1963 I got my first Copicat. It was black and cream. On this unit, the record valve finally died, and I searched everywhere for a replacement. In desperation, I finally rung WEM and ended up talking to Charlie Watkins himself. Not only did he promptly supply me with a replacement, but it came wrapped in a schematic for the model I had originally owned. Now that’s service!

  In 1966 I got my second unit. This one had a new case, a removable single-piece lid, and still used tubes.

The rare Copicat IC900 vari-speed from the EMEAPP collection

  In 1969 I purchased the Mk3 which is my current Copicat. It had the same functionality, but it had become solid state. Despite having the addition of an erase head, this early example still had the magnet in the tension arm, and the bias oscillator was now on the main board.

  The Mk4 arrived on the scene in the early to mid-1970s. It had various technical improvements which included moving the bias oscillator onto a separate PCB. There were other Copicats made after these which used digital delay lines rather than tape. These, however, are outside the scope of this article.

  Using a Copicat is very simple. On most units, there are 4 rotary controls and 3 push-button switches. Starting from the left, there is a SWELL control that alters the volume of the repeat effect. The more clockwise the control is moved, the louder the echo effect becomes. Turning the rotary switch fully in the opposite direction shuts the unit off as the control also includes a mains switch. Moving to the right, we have the SUSTAIN control which determines how much of the delayed signal is fed back to the input. Turning it fully counterclockwise elicits a single repeat, while moving it fully clockwise causes the echoes to race off into a swirly, infinite feedback effect. The next two controls are GAIN1 and GAIN2. They control the relative volume of the 2 inputs as the unit can also be used as a simple two-channel mixer.

  Below the rotary controls are 3 switches that are labeled 1, 2, and 3. They activate each of the 3 playback heads allowing them to be selected in any combination. The first one is the shortest delay, and the third is the longest. When activated simultaneously, a thick, multi-tap echo effect is generated. The output wire is fixed and terminated by a standard 1/4 inch jack, and there is a permanently attached foot-switch that allows the echo effect to be muted as needed.

  On the rear of the unit is a very quaint warning label that says, “Always earth your amplifier.” This is somewhat alarming as the unit does not, as is customary, have a ground conductor! This means the shield of the output cable is being used as the protective ground.

  I should conclude by saying that my unit now has a 3 core cable, a protective ground, and a new grounding scheme that prevents a ground loop. This means the unit now passes a modern PAT check!

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Jim Scott on working with Bob Moog and the World’s Most Famous Synthesizer(s)

Earlier this year, we had the rare opportunity to host an extended visit from storied synth designer, Jim Scott. It was a rare opportunity not just because he’s trying to quietly live his life, but that he quietly lives his life in rural Alaska and seldom dips down into the lower 48.

Jim was present and deeply involved during the heyday of the synthesizer. The Minimoog Model D, Memorymoog and Crumar Spirit all contain circuit design work by Scott. To top that, he was the creator and principal designer of the Micromoog.

He penned this article during his time in residence at EMEAPP, it is chock full of great details from the early and midlife of Moog including his time with Keith Emerson’s famous modular synthesizer. He even added a glossary to help folks unfamiliar with synth jargon.

Fig 1. Jim Scott in 2018
(photo credit: Ed O’Connor, Talkeetna, AK)

My Beginning Days as Design Engineer for R A Moog Inc.

Origins of the Keith Emerson Monster Moog and the Minimoog

By Jim Scott, EMEAPP Technical Advisor

In the beginning

In the spring of 1969, I was a senior electronic engineering student at the University of California Berkeley, when I first became aware of the name Moog and the term “synthesizer.” A local FM station aired Switched on Bach “created on an Electronic Mood Synthesizer”. (Mood is not a typo, but never mind). I bought the album. I was hooked immediately and wrote asking for a job. I had gone into electrical engineering hoping to somehow parlay my degree into becoming a designer of musical instruments. Months went by and I figured Bob had tossed my letter when I got a call from the man himself. Tomorrow he had a few hours between flights. Could I meet him at the San Francisco Airport?

Is the Pope a Catholic? I cut classes for the day. I no longer recall our conversation, but he did invite me to meet him and his synthesizer at the 1969 Audio Engineering Society Convention in Los Angeles a few weeks hence. It was held at the Roosevelt Hotel where Bob had set up a couple of patch cord synthesizers and a prototype Moog MRS (McDonald Recording Systems) continuously variable-speed, electronic music tape recorder in a hotel room. He probably slept there too.

I got there early and listened to his first demo. Due to the publicity surrounding the Wendy Carlos recording, Bob found himself besieged by an ever-changing room full of media, potential customers, music industry professionals and the merely curious for the rest of the day. I got the basics on the first go, so I proceeded to show visitors how the instrument worked all morning and into the afternoon while Bob dealt with the other folks.

I think Bob may have been trying to avoid me because he did not want to hire another engineer. I demoed until about 3 PM. Then Bob called me aside. We went to the balcony outside the door and sat side by side on a couch looking into the dining room below. We continued looking straight ahead for perhaps a minute not knowing what to say. I remember our conversation exactly. Bob broke the silence with “How about 8000 a year?” I responded “Yes”. That was it. Starting salary for a graduating BSEE in 1969 was about 10 grand. No transportation costs were offered so when I graduated I gave my car to the next-door neighbor and borrowed airfare from my grandmother for myself and wife and two kids. My brother-in-law rescued an abandoned Ford Galaxy 500 from his collision yard in Massachusetts and gave it to us. We drove it to Trumansburg New York.I had a rather unique academic career at Berkeley both flunking out in 1961 and graduating with honors from the same university in 1969. How many people can claim that? When I got out of the Navy I was conditionally allowed back. But I had a two-semester D minus average I had to bring up to a 2.0 overall, or no diploma. I had to ace at least half my upper-division courses to raise my GPA high enough. Only junior and senior courses counted toward honors. I had no choice but to earn that ego inflator. I did this working half time and going to school 3/4 time.

First Days in Moogland

So, I arrived on the job 15 Sept 1969, just two weeks after the landmark Jazz in the Garden concert at the Museum of Modern Art (MOMA) in NY City. This was the first highly publicized pubic synthesizer concert in the Big Apple. It was performed by Chris Swansen, our resident composer, Herb Deutsch who instigated the design of the very first Moog Modular Synthesizer in 1964, Robert Moog and one other synthesist. Herbie Hancock was offered the opportunity to be the fourth Moog performer but he declined for fear of ending up with egg on his face early in his career. Four Modular System 1 synthesizers in console-style walnut veneer cabinets were modded for the event by the addition of an auxiliary preset box to each instrument that allowed for the instantaneous selection of one of up to a dozen different sounds. Each of the presets were programmed on a separate card. The active preset was selected by a lighted pushbutton on the front edge. The system was called the “1Ca”, “1” for System 1, “C” for console and “a” for programmable performance modification.

Note: Actually, the 1Ca was not quite the standard Model 1C as listed in the April 1969 price list. The 1Ca included an additional third 911 ADSR. Also, the three oscillators installed in the 1Ca consisted of three 901A VCO controllers paired with three 901B oscillators instead of the stock System 1C which had one 901 VCO plus a single 901A controlling two 901B slave oscillators. This yielded three oscillators that if desired could be operated completely independently of one another for the 1Ca. In contrast, the catalog System 1C had two of the oscillators paired to a common control module. The Mini followed the latter scheme, whereby the third VCO could be operated independently of the other two. (in practice, the actual 1Ca patch also followed this scheme.)

The 1Ca operated using a fixed patch for all the presets. See Fig 3. Each preset card was manually programmed in advance to override the same group of synthesizer control settings, (16 potentiometers and four switches located within the modules). The performer could instantly change the sound of the instrument radically without touching a single knob or patch cord. This fixed patch in fact incorporated a suite of functions patched in a way nearly identical to what would become the architecture of the Minimoog. The Mini would have three oscillators, one of which could serve as a fixed frequency LFO, a noise source, two contour generators, a mixer, one lowpass VCF and two VCAs. (Yes, the Mini has two VCAs, one hidden away and rarely used, dedicated to foot pedal volume control). The System 1Ca Reverb and Fixed Filter Bank did not become part of the Mini but the Ribbon Controller reappeared as the left-hand pitch wheel. As shipped, the Emerson “starter” synthesizer functioned as a Minimoog – with the addition of a limited preprogrammed preset capability to facilitate live performance. In this respect, the 1Ca was the primitive ancestor of the Minimoog Voyager introduced by Bob Moog in 2002.

My first project at Moog as the new hire was to get four more of Bill Hemsath’s preset boxes upgraded and built for the Gershon Kingsley First Moog Quartet debut upcoming 30 Jan 1970 at Carnegie Hall. The group had ordered four synthesizers, basically the 1Ca packaged into Tolex road cases. The synthesizer portion, in non-preset, single-cabinet form, became known as the Moog System 10 (now the modern System 15 with different VCOs). So, I got the presets integrated with the synthesizers. The First Moog Quartet had a degree of success on tour performing with the likes of the Boston Pops orchestra and releasing an album. Bob Moog’s idea was to sell this machine or a variant thereof as a standard product for live performance, but this never happened. To this end, I designed another upgraded preset card, and it was this second version which eventually went to Keith.

Bob Moog’s Vision

Bob was not in favor of developing an instrument like the Mini, thinking there was no market for it, and anyway, he did not want to take his “shop” in the direction of mass production. He preferred instead to remain in the pioneering forefront of creating new electronic tools to advance the art of music by working with customers one-on-one to create innovative products.

Moog was put on the path to developing the modern synthesizer by avant-garde composers who wanted devices to create novel musical effects that were difficult or impossible to achieve with available technology. He designed the basic “instruments” in response to requests for controllable tone sources, tone modifiers, articulators, effects, playing controls and the like. Thus were born the VCO, the VCF, the ADSR, the Fixed Filter Bank, the triggering one-volt per octave Keyboard and the Ribbon slide control (in addition to other devices) – as first suggested by folks like Herb Deutsch, Vladimir Ussachevsky and Wendy Carlos. By 1969 the “instruments” had been renamed “modules” and collections of them organized into a system had been dubbed “synthesizers”. A powerful unifying feature of the Moog synthesizer was the extensive use of control voltages to set operating parameters. This may have Dr. Moog’s most significant innovation for the music world, as it allowed one module to profoundly affect the sonic character of another. A simple example would be the use of an LFO to introduce a variable depth vibrato to a VCO.

The central theme in Moog’s career was this collaboration with artists. It necessarily was his greatest strength in his life’s creative work. But it also was a source of much financial distress in the early days 1965 until 1971, whereby he was forced to sell a controlling interest in his company to get out of a near-fatal debt load. He often accepted orders for one-offs that may or may not have had the potential to put into production. By the time I came on the scene he had amassed a rather daunting backlog of orders for which he had taken substantial down payments. Lawsuits were being threatened. Most of the projects were guaranteed to be money losers as Bob, in the goodness of his heart, had agreed to a low price as a favor to the customer, optimistically thinking he could make good on the promises and still stay in business. In 1969, while things were still looking rather rosy due to the large volume of recent modular sales, he added to his engineering staff. This was both to develop new products and to whittle down the pile of unfilled specials orders, which had become impossible for him to fulfill on his own. I, Bill Hemsath and Bob Shen came aboard during the summer and fall of 1969 to supplement his first engineer, Gene Zumchak. I do not know when part-timer engineering grad student Chad Hunt came aboard, probably mid-1969.

The 1Ca That Went to Emerson

Of the four 1Ca Systems built, only one was ever sold – to a Brit we had never heard of named Keith Emerson. I did the final checkout of the instrument before it went out the door. I sent with it with a drawing showing the standard “Mini-type” patch diagram. All presets were factory programmed to produce usable demo sounds using that patch. I also sent a brief three-page set of instructions. The pen and paper original documents in my handwriting still exist in the Moog Collection, Kroch Library, Division of Rare and Manuscript Collections, Cornell University, where I found and scanned them last year.

See Fig 2. A frequency counter for tuning sits at center in front of a blank lower-tier panel. Left to right the upper tier has a three-901A/three-901B oscillator bank, a passive highpass/lowpass tone control and output attenuator panel, a 903 Noise Source, a 905 Reverb, a 907 Fixed Filter Bank, a 904A Lowpass VCF, two 902 VCAs, three 911 ADSRs and a double Multiple module. The lower tier consists of non-modular panels (they are hard-wired and non-removable). On the left, we see two VCO Control Voltage Routing panels and two Four-Channel Mixers with Multiples. The photo shows an unreadable mystery panel left of center. The panel right of center selects which oscillator to route to the frequency counter. Then comes another Control Voltage Routing panel, this one for the VCF. After that we see another Routing Panel connecting the keyboard triggers to the ADSRs and connecting ADSR outputs to VCAs. The second to last panel provides direct patch cord access to Keyboard and Ribbon control voltage and trigger outputs. Finally, the Power Supply panel fills the last space. A Ribbon controller rests atop the keyboard. This synthesizer however is more than a Mini even when you take away the 905 and the 907 in that it has two mixers and three contour generators.

Note that many control connections are made without patch cords, reducing the jungle of wires. These hard-wired, patch-cordless connections had become standard features of all the modular synthesizers in the nineteen sixties. This feature naturally facilitated adaptation of the System 1 for live performance. The Minimoog carried this concept further by eliminating all patch cords. The Mini project began a few months or so after the1Ca came into being. The initial impetus came from Gene Zumchak, but Bob Moog was not buying the idea. Bill Hemsath then on his own initiative created the Mini A Model in Nov 1969. The Minimoog Model D followed a year later as a direct descendant of the 1Ca.

The 1Ca stands as a pioneering synthesizer, taking the first steps along the path out of the studio and onto the popular music stage. Moog and the music industry were fortunate that one of them at least came into the hands of a performer who brought the synthesizer to worldwide attention.

Fig 2. The 1Ca Before Shipment to Keith Emerson Originally built for the MOMA Concert at the Garden, 30 Aug 1969 (photo credit Kroch library)

The Preset Box for the 1Ca rests on top of the cabinet. It was preprogrammed with sounds according to the patch diagram, Fig 3. The photo shows only 6 cards installed, with the leftmost being the clear card to cancel the preset function. There is room for 7 more preset cards. A 1974 concert photo shows this same preset box atop Keith’s rig with ten preset cards installed and space for two more.

Fig 3. The Patch Diagram Sent to Keith Emerson Drawn to document the setup for the original Emerson synthesizer, showing a patch of the synthesizer in my handwriting. The drawing is labeled as “1cA”. (photo credit Kroch library)

Keith claims on his web site that we never sent any documentation whatsoever. This is not true. Either he had forgotten getting what I had sent, or British customs failed to put it back in the box, or someone lost it upon unpacking.

Lucky Man

A number of authoritative sources – including the book “Classic Keyboards” (page 351), information on Keith’s website and statements by Greg Lake and Carl Palmer, tell us that Keith’s improvised solo at the end of the great ELP hit Lucky Man was performed on the 1Ca instrument. These accounts, unfortunately, appear to be based on incorrect recollections recorded decades after the events. The story had it that it had arrived at the recording venue, Advision Studios in London, the day before completion of the album. This was in July 1970. On the last day, the band hastily had to concoct a filler number to complete contractual requirements for the number of minutes on the album. They already had recorded their entire repertoire. So Lake and Palmer laid down all the tracks for a new number based on the first song Lake ever wrote (at age twelve) called Lucky Man while Keith was out visiting a pub. Keith returned and the band decided that Keith needed to add a keyboard presence to the song. According to the legend, the brand-new Moog was brought into the studio to see if a synthesizer solo would do for the purpose. Keith had no idea how a synthesizer worked at that point by his own admission. He played an experimental line at the end of the recording that replaced a Greg Lake guitar track. He did not know that the tape machine was running. To Keith’s eternal dismay, it was a one-take “keeper” because there were no more tape tracks remaining for a second recording to “get it right”. The crew did not want to risk overwriting the first take, which everyone liked (except Keith). For the next nearly 50 years I have been taking some credit for Lucky Man because I assumed Keith had to have used one of the presets I had programmed back in Trumansburg in order to produce a useful sound on an unfamiliar instrument. Alas! My claim to be a footnote to progressive rock history turns out to be untrue. Brian Kehew (keyboard tech and backup performer with The Who for some 20 years) has researched the matter thoroughly. Here is the real story:

In fact, that Lucky Man instrument was a large modular system, equivalent to the modern-day Moog System 55, owned and well understood by Mike Vickers of the group Manfred Mann. It was the first Moog synthesizer in England. He kept it at Advision and made it available by the hour for recording sessions. It was either Vickers or producer Eddie Offord who set up the synthesizer for Keith to play. Once the band had created Lucky Man, they realized they must have their own synthesizer for a series of upcoming performances happening before the release of their first album, the eponymous Emerson Lake and Palmer. They located the Garden Concert 1Ca for sale by our sales representative Walter Sear in NY City. He had been trying to sell it for a year. It was ideal for Keith, as it had been configured specifically for stage performance for use by non-technical musicians. The Vickers instrument was not only non-programmable but also was not always available. And the Minimoog was still a half year in the future.

Accordingly, arrangements were made for its purchase through our British representative, Feldon Recording. Apparently, it took a couple of months to clear customs. We know for sure that ELP possessed it by 29 Aug 1970 because it clearly shows up on stage (although barely used) in video footage of the ELP performance at the Isle of Wight festival. This was 364 days after it was first used in the MOMA concert, almost exactly one year previously. It was also in August 1970 that the album was mixed down for release in November.

The afterthought Lucky Man went on eventually to become arguably ELP’s best-known song. It almost did not happen.


Fig 4. The Instructions Sent to Keith Emerson Page one of the three pages in my handwriting (photo credit Kroch library)

The original 1Ca was subsequently added onto to become the present-day Emerson Monster Moog, now owned by EMEAPP. The entire Emerson Moog has been replicated by Moog Music Inc in Asheville NC in recent years (five sold at $150,000 a crack). It had grown to something like its present size by 1973 or 1974 when last I had my hands on it for servicing by Moog Music Incorporated in Buffalo NY. The original 1Ca cabinet from the 1969 Concert at the Garden to this day still exists as the slope-faced portion near the bottom of the stack of cabinets, albeit with many of the original modules swapped out or moved, but also with about half the original complement still in or near their original locations. The original bank of drifty 901A/B VCOs has been replaced with pitch-stable 921A/B VCOs.

Fig 5. The 1Ca Section of the Emerson Moog Slant-face portion with module complement modified from the original. The entire Emerson synthesizer has been completely reconditioned. It was performed in the Emerson Event at the EMEAPP Studio in 2019. (photo credit EMEAPP)

The separate preset box with internal trim pot programming knobs is now gone. The ten preset circuit functions are now incorporated into the five vertical-faced modules in the cabinet at the bottom of the Monster Moog stack, below the 1Ca. The original circuit boards have been junked for a new design. The programming settings for each preset are accessible by removing the blank panel beside each of the modules. The three-tone oscillators for each preset are screwdriver fine-tuned from the front panels.

Fig 6. Programming Modules, Emerson Moog These modules replace the original programming PC board auxiliary box. (photo credit EMEAPP)

Fig 7. Remote Preset Selector This upgrade selects which of the ten presets to activate.
(photo credit EMEAPP)
Fig 7. Remote Preset Selector This upgrade selects which of the ten presets to activate.
(photo credit EMEAPP)

Dodging the Bullet

In late 69 or early 70, as a consequence of staffing up the engineering department at the time that the market for large expensive modular synthesizers had been saturated and sales were drastically declining, our General Manager John Huzar was faced with a cash flow crunch. This necessitated reducing the number of engineers on the payroll. First to go was Gene Zumchak who was not an analog designer and who personally did not get along with Bob Moog. Next in the crosshairs was either Bob Shen or Jim Scott.

I was straight out of school and fresh on theory and mathematical techniques. Although I had taken courses on circuit design, I had never designed a real, honest-to-goodness practical circuit of any sort in my life. Moog, Hemsath and Hunt had years or decades of experience. Here I was, plunged into the deep end to do or die. Bob expected his engineers to produce results without needing too much babysitting from him. By pure luck, shortly before I came on board in late 1969, Shen had been handed the difficult job of replacing the pitch-unstable 901 VCO with a new-design stable 921 VCO. This new oscillator was slated to be installed in the programmable preset synthesizers being developed for the First Moog Quartet. His design failed and was discarded, since the stable exponentiator that produces an accurate equally tempered scale had yet to be discovered by me, Bill and Bob the following year. First Moog Quartet players had to make do with drifty and inaccurate 901 VCOs, although not without a lot of grousing. Best I could do was to advise them to keep a finger on the Ribbon to bend the notes onto pitch – not an accustomed practice of keyboard players. Jazz musician Chris Swansen never had a problem in this regard, as he naturally had adjusted pitch constantly when he played brass instruments.

I was handed a problem I had no idea how to design to satisfy a one-off special order on backlog. This was to deliver a module with two knobs to control a tunable frequency, variable width, bandpass filter. Bob did not have a circuit in mind when he had taken the order so I was not going to get much help from that direction. But I had cut classes to attend an electronics trade show in San Francisco before graduation. There I was shown a potted module a salesman had previously tried to sell to, guess who, the R A Moog company in Trumansburg, that exactly met specifications for our order. So, I ended up with the easiest project imaginable – entailing putting the purchased epoxy encapsulated module behind a panel and wiring it to two front panel potentiometers. Slam dunk. Brian Kehew tells me it was the only example of this product ever sold by the manufacturer. General Manager John Huzar, having no technical smarts whatsoever, sees that Scott succeeded in his design project and Shen failed. So quite unfairly the guy with seniority and a more advanced degree is sent packing and I am kept on, giving me some breathing space to get up to speed as a circuit designer. I learned in a hurry in large part by studying Moog Modular schematic diagrams.

As has been mentioned earlier, the First Moog Quartet preset modular synthesizer was supposed to be followed by a production version with a more capable preset box that worked on the same principle – that of using remote photoresistors on the cards to parallel control panel potentiometers in the modules. This was my first production device design project. The programmable modular synthesizer was Bob’s concept of the way forward to bolster lagging sales by getting the patch cord synthesizer onto the live performance stage, opening a new market. To that end I designed a fancier preset box that had the added feature of programmable mixers, which for one thing, could blend together different sound sources to yield a sort of a rudimentary patching capability. Work on this project ended when it was decided around 1 July 1970 to go forward on the Minimoog design effort from the B Model concept prototype to the preproduction C Model prototype. The redesigned preset box with programmable mixers did make it to market at least once – as part of the Keith Emerson Moog.

This also was around the time my one-off vocoder was delivered to State University of New York to stave off legal action for non-fulfillment of a contract two years prior. The difficult part of this project was the design of two 22-band comb filters (similar to the Moog 907 and 914 Fixed Filters) with extremely stringent requirements for sharp rejection of out-of-band frequencies. Bob had no circuit implementation ideas for this design either, so I was left to my own devices. Simple textbook designs were not adequate, nor were commercially available, custom-designed, ready-to-use filters. Starting from scratch, I finally hit on a type of filter that was of sufficient selectivity, accuracy, and manufacturability. Chad Hunt pirated a computer design program for this type of filter, and he snuck in some midnight computer time at Cornell University to calculate the component values. The filter worked like a champ – and was very easy to calibrate in test. Rumor has it that this vocoder is still in operation in Europe somewhere. The Moog Foundation home web page credits Bob Moog with the design of this filter as one of his eight great achievements. Nothing could be further from the truth, and the proof is in my logbooks and the Moog Archives at the Cornell Kroch Library, where the detailed design is archived in my handwriting. R A Moog Inc lost a bundle on this project, I doubt the $4000 we got even covered the cost of the parts, and I always felt bad that I was responsible for a severe cost overrun. But we did not get sued by the State of New York at least.

Enter the Minimoog

Subsequent to the departure of Gene Zumchak, Bill Hemsath, on his own initiative, created the first Minimoog prototype, the A Model, along the lines Zumchak had campaigned for. With Bob, he also created the two B Models. These instruments were so whole-heartily accepted by the few musicians who had access to them that the decision was made to move forward to develop a production Model, despite Bob Moog’s strong reservations about the sales potential of such an instrument. Bob, I think, relented and allowed his staff to proceed because of the possibility of attracting a sorely needed investor to put some capital into the company. It is his to his credit that Bob also enthusiastically participated in the design of the prototype Mini C, which with little change became the production Mini D.

Meanwhile back at the ranch ….

Zumchak, who had failed to impress on Bob Moog the need for an all-in-one live performance synthesizer, prevailed on fellow Ukrainian and entrepreneur Bill Waytena to found Musonics Inc near Buffalo to develop his ideas. With the consultation of a moonlighting circuit designer named Fred Reinagel, he designed an instrument called the Sonic Five, built into a wooden cabinet and aimed at the educational market. This instrument was subsequently repackaged in a more portable suitcase-type enclosure to appeal to the live performance market and renamed the Sonic Six.

After Moog sold control of R A Moog Inc to Musonics, the two companies were merged as Moog Musonics Inc. Moog Musonics produced both instruments for a while, but the Mini outsold the Sonic to the extent that the latter had to be retired from production. Bob was amazed at how the Mini sold. He told me, rather ruefully, in Trumansburg after the first 10 D Models were completed, “I doubt we will ever sell 200 of these”. When the Mini proved to be the salvation of the company, Bob had totally forgotten the memo I wrote in Trumansburg predicting the Mini would become a classic musical instrument. No copy of that memo has ever been found.

To supplement the big Emerson Modular, Keith also later added a Mini D to his rig, often employing it for bass. Thus, his setup included the ancestor 1Ca and the offspring Mini D on the same stage, and he was able to play both simultaneously live in front of major audiences.

Afternote: The matter of which synthesizer was used in the recording of Lucky Man deserves more attention, but this is better handled in a separate document, as the detailed story is beyond the scope of this article.  EMEAPP has more evidence in hand and is expecting more, which we believe will prove that the Vickers synthesizer produced the ground-breaking Lucky Man track.


For synthesizer newbies, here are the definitions of some of the terms used in this article:

VCO Voltage Controlled Oscillator, often used as a musically-pitched tone source. The 901A Oscillator Controller operated one or more slave 901 B Oscillators. The 901 VCO consisted of a 901A and a 901B housed in a single module.

LFO Low Frequency Oscillator, often sub-sonic, which, for example, can introduce vibrato or tremolo.

VCA Voltage Controlled Amplifier. A pass-thru device that varies the loudness of a steady sound, such as the unvarnished output of a VCO, in response to a control voltage.

ADSR Attack, Decay, Sustain, Release controller. The main function is to generate a one-time transient voltage in response to a trigger, such as derived from a keyboard. Typically, the contour (or envelope) that it produces is patched as a control input to a VCA to articulate notes in response to triggers produced from the keyboard.

VCF Voltage Controlled Filter. This is a pass-thru electronic tone control that typically may modify the timbre of an oscillator. The most commonly used type, the lowpass filter, progressively brightens the sound as the control voltage increases, and vice versa, such as in response to a foot pedal or a dedicated ADSR.

Mixer Combines several audio signals or control voltages. One common use is to add together the sounds of a bank of VCOs tuned to a musical interval such as unison, octaves or a triad.

Multiple This refers to a group of phone cord jacks wired together so that a single output signal (audio or control voltage) can be fanned out to several destinations. For example, one may wish to split the pitched output of an oscillator to connect the signal to the audio input of a VCF and/or VCA, while at the same time applying the same signal to the control input(s). This self-modulation technique leads to special tonal effects.

Modular Synthesizer This refers to a construction whereby one may choose a set of individual patch cord modules (such as VCO, VCF, VCA) to plug into a cabinet, and to have the freedom to reposition them or swap in different functions. Nowadays the meaning has changed to refer to patch cord synthesizers which in fact are not reconfigurable owing to having a single unified front panel. In this article we use the term in its original sense.

Reverb This refers to a spring reverberation module. This compact electromechanical device emulates an echo chamber to add presence to sounds.

Fixed Filter Bank A bank of bandpass filters featuring a sequence of center frequencies similar to a hi fi equalizer. However, unlike an equalizer, the overall effect with all channels set to max results in a very “lumpy” response curve to color the sound. One use was to impose formants on the output of a synthesizer.

A Great Regional News Story on EMEAPP

It was fun giving FOX 29 reporter, Bill Rohrer, the full run of the EMEAPP house, and he had a blast! We spent a day with him doing interviews and shooting footage of vintage synthesizers, amplifiers and effects.

Check out this great report on how Vince Pupillo, Sr. gave birth to this unique collection, and learn how it is becoming one of the world’s greatest accumulations of historically significant musical equipment.

EMEAPP’s Executive Director, Drew Raison, walks you through sections of the huge 30,000 square foot facility and explains how EMEAPP works. A highlight is getting to see (and hear) the sounds of Keith Emerson’s famous Moog modular synthesizer, demoed by Vince Pupillo, Jr.

Care to see a long-form tour of EMEAPP? Check out this online tour we did for a partner back in January of 2021. Quite a few things have changed since then, but it’ll give you a good idea of what EMEAPP is about.

Like what you’re seeing? We encourage you to join us with a FREE MEMBERSHIP! You can also find up-to-date postings about EMEAPP on both Facebook and Instagram.


Is This Frank Zappa’s Secret Sauce? Here’s A Look At His Beloved MU-TRON BI-PHASE.

We have a few Mutron Bi-Phase phase shifters at EMEAPP, we adore them and their unique sound. While the majority of gear we have is in prime condition, Frank Zappa’s Bi-Phase has been ridden hard and put away wet. Saying that it was well-loved might be an understatement, it is clear that the Maestro and his techs spent many years disassembling and modifying this beloved unit.

If every piece of gear has a story to tell, Zappa’s Mutron can probably write a book. This is why it makes us so happy to see it make an appearance in this month’s GUITAR WORLD magazine. Dweezil Zappa even got involved to give the reader some insider info on this very special piece that was a critical part of his father’s sound.

As you’ll read in the Guitar World article, Zappa’s Bi-Phase is also well represented in the new book, STOMPBOX: 100 Pedals From The World’s Greatest Guitarists, chock full of sexy photos by our good friend Eilon Paz. Eilon visited EMEAPP to shoot a few dozen rare and unique pedals for this book as well as another called VINTAGE & RARITIES: 333 Cool, Crazy and Hard To Find Guitar Pedals.

Want some more great intel on Frank Zappa and his legendary guitar sounds? Check out this EMEAPP article, Frank Zappa’s Guitar Amplifiers- Want to take a peek inside? This article takes a look at what makes these amps special, including a great tech write-up by Bryan Parnell.

And for the icing on the cake, here is his son, Dweezil, lighting up his father’s amps on a visit to EMEAPP in advance of his Hot Rats and Other Hot Stuff concert tour.

Are you a member of You should be, it’s free! Click here to join us.

Want a quick look at Keith Emerson’s Stage and Studio Gear?

The eagerly-awaited video release of the 2016 Keith Emerson tribute concert is upon us! It is appropriately titled “FANFARE FOR THE UNCOMMON MAN”.

We were asked to create a quick tour of Keith Emerson’s stage and studio gear for their pre-release event and we were glad to oblige. The online reunion ran on March 5th and was a blast!

Steve Lukather, Steve Porcaro, Jeff “Skunk” Baxter, Marc Bonilla and others got back together to announce the release of the tribute concert video that is loaded with top-notch performances from many of Keith’s friends and compadres.

You can find the tribute concert for sale below, it is worth having! The best part is that all proceeds benefit the focal dystonia research, the disease that attacked Keith Emerson.

From the Cherry Red Records website:

A new concert film and album documenting the May 2016 tribute show honouring the late Keith Emerson.

The Official Keith Emerson Tribute Concert will be available as a four-disc set featuring DVD and two CDs capturing the entire two-and-a-half-hour event and a disc of Bonus interviews.

The show featured a roster of rockers including Steve Lukather, Steve Porcaro, Eddie Jobson, Jordan Rudess,  Brian Auger, Jeff “Skunk” Baxter, Vinnie Colaiuta, Marc Bonilla, Gregg Bissonnette, CJ Vanston, Troy Luccketta, Rachel Flowers, Terje Mikkelsen, Philippe Saisse, Travis Davis, Ed Roth, Mike Wallace, Mick Mahan, Karma Auger, Rick Livingstone, Jonathan Sindelman, Joe Travers, Kae Matsumoto, Aaron Emerson, Dan Lutz, and Michael Fitzpatrick. The event also featured Emerson’s son Aaron, and members of his solo band and his Three Fates Project group.

The show, which was held at the El Rey Theatre in Los Angeles, offered a career-spanning celebration of Keith’s work, including music from ELP, The Nice, Three Fates Project and the Keith Emerson Band.

The DVD also features artist interviews, behind-the-scenes footage, tribute speeches and a gallery of rare photos provided by the Emerson estate.

George Secor- Music, Mathematics and the Miracle Temperament

Today is a year since George Secor passed on at 76 years of age, what a great opportunity to look back on his visit to EMEAPP back in 2018.

Yes, he was a focused and precise musician and mathematician, his academic work led him to discover the microtonal miracle temperament and even have a microtonal interval named after him. But face to face, George was a jovial and kind individual who really enjoyed the excitement of composing and performing music on unique instruments.

He was an accordionist, but he favored the Moschino Free Bass instruments rather than the traditional type. This allowed him more flexibility in chord structure and allowed for more comprehensive musical figures.

Secor also developed a musical notation system that allowed for the limitless microtonal script, you can see the basis of this at You can also see the symbols utilized in Sagittal as well as assigned pitches and more at

Three of this type of Scalatron exist in the world

But for us, the payoff was time spent with George on our vintage Motorola Scalatron, a synthesizer that allows the user to “play between the cracks” of the standard western 12-note octave. In fact, it is capable of dividing an octave into 1,056 notes!

Our original Motorola Scalatron

When George passed, he graciously donated his personal Motorola Scalatron to EMEAPP knowing that it will be viewed and used by many for generations, rather then ending up in a dumpster in Southern Illinois (this almost happened!).

Motorola Scalatron donated to EMEAPP by Secor

It was our honor to present George with a posthumous EMEAPPP Lifetime Achievement Award in late 2020 to acknowledge his efforts in the world of microtonal research, scale design and notation.

Enjoy this video and take some time to research George and all of his musical doings. He was a great family man and we are proud to have had the opportunity to spend some quality time with him.

Happy trails, George!

The Story of the EMEAPP ARP 2500 Modular Synthesizer


I remember the first time like it was yesterday, being face to face with an ARP 2500 modular synthesizer at the Electronic Music Education and Preservation Project near Philadelphia. Everything about the instrument was flat-out sexy, from the knob colors to the natural wood to the intriguing matrices. I had seen many pictures of a 2500, but it was so different in person.


The ARP 2500 was an analog modular synthesizer created by ARP Instruments, manufactured from 1970 through 1981. The units were costly and technically advanced challenging for the novice, only 100 or so units were created. They are truly unique and have a sound of their own.

You might be familiar with the dynamic intro to Elton John’s “Funeral For a Friend”. The epic piece was created by producer David Hentschel on an ARP 2500. You also hear it all over The Who’s album, “Who’s Next”. In addition to using it as a keyboard synth, Pete Towshend processed his guitars and keyboards through sets of modules on a number of songs.

French electronic music composer, Eliane Radigue used her ARP 2500 almost exclusively throughout her career. Synthesist Jean Michel Jarre considers the 2500 to be one of his favorite instruments. We share this in common.


Nowadays, I have the opportunity to be in the presence of this ARP 2500 on an almost daily basis as the Director of EMEAPP. With two wing cabinets on stands and fully-loaded with modules, this is truly a rare bird. Only 100 or so units were built and each was a custom order; there were no standard configurations.

We care for quite a few ARP instruments at EMEAPP. We always have a white Odyssey wired up near with a Pro Soloist, our Quadra is always at the ready. But, the ARP 2500 is the Godfather of the collection and sits on a high pedestal, figuratively and literally.

It Grows

Our ARP 2500 began with a single large cabinet synth. Years later, a second large cabinet rig was sourced, which sat atop the other for years. We lovingly called it our ARP 5000. Then our curator caught wind of an über-rare matched pair of wing cabinets with their original wooden stands. They were clean and good looking– cherry switch matrix heaven!

OUR “ARP 5000”

Then it was time to merge the beasts, to comingle the two wide-cabinets into a large center cabinet with a pair of wings. Tim Warneck was brought into the ring with the intention of assembling our beautiful monster. Our first goal was to make certain that the power supplies were in top-order, a requirement to prevent damage to the modules. Next Tim populated the wing cabinets with modules from the donor cabinet.


The good news about the 2500 is that the modules can be configured in almost any way we like. We discussed our module layout plans and Tim took action. Then, after a good clean out and inspection, the units were powered up and tested for basic function.



We have done quite a few sessions with our ARP 2500 in the last three years, beginning with the single-cabinet machine and then with the behemoth above. Some sessions were quite simple, but others were deep and complex. In any case, a lot of work goes into an ARP 2500 session, especially when it comes to planning.


Our first ARP 2500 session was with Scottish artist, Luke Fowler. We had quite a learning curve to get comfortable with matrix patching, for both audio and voltage. We had a blast getting a taste of each module, some are really unique! The session went very well, the instrument behaved nicely and was a joy to work with. Read up on Luke Fowler here.



Our next sizeable ARP 2500 session was in support of a unique project indeed, to recreate the Cylon character’s voice from the TV series, Battlestar Galactica. Joe Grandberg and Chris Dexter came to EMEAPP to discover and recreate the original synth component, derived from an ARP 2500.

Joe brought a beautiful selection of vintage gear for the session to help determine the proper sound and operation of the 2500. It took quite a bit of effort, but the outcome was worth it! Check out the entire series of the process, it’s really cool!


One sunny Philadelphia afternoon, Dina Pearlman of the Alan R. Pearlman Foundation reached out to us. She spoke about a huge video project that was underway that could benefit from some resources that we might have at our facility. Alan R. Pearlman was A. R. P. of ARP. He, along with partner David Friend and a crew of talented folks created the 2500 and many other vital instruments. The Foundation has always been of importance to us, seeing as how Alan played such an important role in synthesizer development. He was a true pioneer.

Dina indicated that video producer, Alex Ball, was nearing completion of this full-length video that does a deep-dive into the history of ARP synthesizers. He needed pictures of some rare and unique instruments, many of which we have under our roof. It was quite an effort, but we sent him dozens of images and video demos for the project.

Check out the finished product called Electromotive: The Story of Arp Instruments. You’ll see many of the images, videos and sound samples that we provided. It was a great project for EMEAPP to take on as this video will have historical and informational value for decades to come.


Another great 2500 session series was with synth pioneer, Don Slepian, who spent some quality time with the instruments when they were still in manufacture. He also had the rare opportunity to create original compositions on the famed ALLES computer, built by Bell Labs in 1979. It was fascinating to watch Don utilize individual 2500 modules similar to Pete Townshend, using a series to modify an external audio source. In the videos below, Slepian used a wooden flute and an ARP Quadra run through a series of modules, proving that the black and white keyboard certainly isn’t necessary.

Don ended up creating an outstanding series of music and videos during his sessions at EMEAPP. Keep your eyes open for a future article about Don, he has an interesting history and a huge body of work.

Don was even gracious enough to give the audience a general tour of the EMEAPP ARP 2500.



Vince Jr and I have created quite a few episodes for our Sonic Test Drive series. Here is Vince taking our ARP 2500 for a spin. In this video, he added a Roland CR-78 CompuRhythm drum machine and an ARP 1613 sequencer. We ran the rig through our vintage ARP8 mixing board as we did with Don Slepian’s session. As you’ll hear, it sounded pretty huge!


I have certainly gained an immense amount of ARP 2500 knowledge over the last three years, I am a better synth guy for it. I also truly appreciate every day that I get to walk the halls of EMEAPP and be surrounded by such a rare and valuable collection of historically significant gear like the ARP 2500. I hope my access to this instrument continues for a long time, as it fascinates and intrigues me on a continuing basis. It lights me up when I see it, I can’t wait to make amazing sounds at any opportunity in the future. Thanks, Alan R. Pearlman, David Friend and the rest of the ARP team, you did a great an amazing job.

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The TECHNOS ACXEL Resynthesizer

Recently, we took delivery of a very rare and unique synth whose perspective on sound creating would be considered unique. The Technos Acxel was created in the late 1980s and holds a strong position in the hierarchy of digital synthesis. We asked Ryan Gaston of Perfect Circuit to give us an analysis of this unique machine.

The Technos Acxel is, with little doubt, one of the most peculiar instruments I have ever encountered. Living in 2019, it feels safe to say that an instrument with its combination of qualities would be highly unlikely to emerge in this day and age. It focuses on complex and obscure synthesis methods and has a strikingly peculiar design: a design which, while quite well-suited to its rich (albeit quirky) internal architecture, would no doubt have been quite expensive to develop/produce…and thus, quite expensive for the end user. Technos was clearly driven and ambitious, sparing no expense to pursue their vision of what making music could be like—and this ambition led them to take significant risks.

The Acxel was one such risk, and one that sadly did not end with fame or fortune: approximately 35 of these instruments were produced before the company closed its doors in 1992. The name “Technos” faded into obscurity and, aside from occasional mention in historical texts (such as Mark Vail’s Vintage Synthesizers), garnered little or no continued attention. To my knowledge, the Acxel as of yet has produced no Minimoog- or OB-Xa-style chart-topping hits; it didn’t appear on stage among elaborate prog rock or synth pop groups; it didn’t find a home in any giant, acclaimed Hollywood studios. Instead, it found its way into the homes of experimental synthesists and/or collectors, and few seem to have publicly surfaced since.


Personal History with the Acxel

I was working at Perfect Circuit in Burbank, CA when I first encountered the Acxel. At that exact time, we had a host of odd and uncommon synths: a Yamaha CS-80, a Synton Fenix 1, a Waldorf Wave…all exciting things for any synth enthusiast. Among the pile of things on our testing bench, though, was an Acxel. I had never seen or heard of it before, and at first glance was not even sure that it was a musical instrument. I was tasked with learning how it worked, so as to be able to determine whether or not it was actually in functional condition.

After several days poring through manuals and testing features one by one, I gained a profound respect for the instrument. I maintain that I have yet to encounter an instrument with such a singular workflow—evidence that its creators at Technos had a very complete and sophisticated way of conceptualizing sound. It is completely distinct from the then-mainstream approaches of subtractive synthesis, sampling, and digital methods such as FM or PD, instead borrowing bits of each approach to create something unique. It quickly became one of my favorite instruments, both due to its bold vision of how sound can work, and due to its clever interface—but more on that soon.

That instrument eventually found a home with a private collector, and I accepted the fact that I would likely never see one again. But, two years later, another found its way to our shop. Happily, this instrument eventually wound up with EMEAPP: a perfect fate for something so peculiar. All too often, rare instruments such as this circulate within closed networks of collectors and eventually fade from public visibility altogether, resulting in an unintentional erasure of the fringe areas of historical instrument design. And while these boundary-pushing instruments may not be the most influential when considered in terms of widespread use, they often have powerful, unique potential to challenge the way that we think about instrument design, sound design, and music-making altogether.


The Technos Acxel Itself

The Acxel is comprised of two pieces. The Solitary, a large, rack-mountable chassis, houses the instrument’s signal processing and audio/MIDI I/O boards. In practice, the user does not interact much with the Solitary, aside from loading the OS or timbres from a 3.5″ floppy disk. Perhaps comically large by modern standards, the Solitary houses an astounding array of electronics: including basic I/O boards, the Syncards (voice cards), and depending on the exact model/configuration, the Acxelizer board itself.

The second piece, the Grapher, is the actual user interface…which is to credit for most of the Acxel’s cult reputation. The Grapher is a tablet-like control surface that allows simultaneous display and editing of all of the Acxel’s internal parameters via a series of over 2000 small LED-embedded capacitive touch plates. The Grapher’s Matrix of touch plates changes in function depending on what parameters have been selected for editing: so the Grapher is at once a menu/page-based display and a means of changing values at the touch of a finger. One can think of this as being somewhat like the Fairlight’s light pen—but it is activated simply by touch. Again, this is the way that all internal parameters are edited: envelopes, wave shapes, signal levels, and much more are all created and displayed through this absolutely sci-fi-level touch interface.

The Acxel does not provide a dedicated playing interface, though: it must be paired with a MIDI controller. This was a departure from Technos’s prior design, the 16pi, which was itself not dissimilar to an Acxel with a keyboard. Instead, users were to determine their own means of interacting with the instrument.


What is Additive Synthesis?

But the user interface is not the only peculiar thing about the Acxel: its means of sound production is also markedly uncommon. The 1980s were a bold time in instrument design; designers’ increasing reliance on digital technology for sound generation and control meant that, theoretically, almost any musical concept could be turned into an instrument. As such, some designers turned to theoretical techniques that previously might have seemed impractical—including additive synthesis.

Mainstream analog synthesizers primarily rely on subtractive synthesis—that is to say, they rely on harmonically rich oscillators (saw waves, square waves, etc.) as a sound source, then using filters to remove harmonics and emphasize certain parts of the sound spectrum in order to create interesting sounds. This is the realm of the Minimoog, ARP 2600, Oberheim SEM, and countless other classic analog synths. Additive synthesis, however, works differently: rather than using a small number of harmonically rich oscillators and a filter as building blocks, it instead typically uses a large array of sine oscillators carefully tuned to specific intervals and set to specific volumes in order to construct a sound from the ground up. This is a somewhat more atomic/elemental approach; and because a convincing additive “voice” might require dozens of oscillators and amplifiers,  additive synthesis was too impractical to implement and too tedious to program in an analog context. However, when designers began to rely on digital sound generation and digital control, such a feat was suddenly within reach.

This is the fundamental approach of the Acxel. This LED-laden oddity has a whopping 32 oscillators per voice, each with their own amplifiers. Each voice is rounded out with two-operator FM capability, two filters, and a master amplifier for voice-level volume control. Moreover, there are 64-stage envelope generators for practically every sensible destination—each oscillator in each voice has its own pitch and volume envelopes, and several voice-level envelopes control FM index, filter cutoff frequency, and overall voice amplitude. Yes—there are literally dozens of envelopes for every single voice (and the basic configuration has eight voices in total).

Of course, having this sheer number of sonic resources in one instrument is pretty jaw-dropping…but one of the most fascinating aspects of the Acxel lies in how all of these resources are controlled.


Additive Synthesis in the Acxel: the Spectrum Concept

Technos cleverly organizes the key parameters of additive synthesis into spectra in order to be able to understand the relationship between settings for each of a voice’s internal oscillators. There are several spectra: the amplitude spectrum, phase spectrum, integer spectrum, and beating spectrum. When navigating to any of the pages for editing these spectra, the touch plate LEDs illuminate in order to reflect the current settings for each oscillator in order, basically creating a touchable bar graph representing all of the settings for the selected spectrum parameter. One needs only to swipe their fingers across the Grapher’s touch plate matrix in order to alter these settings, as if it were a set of sliders or drawbars.

The amplitude spectrum defines the relative loudness of each oscillator, allowing users to emphasize or de-emphasize any overtone they desire. The phase spectrum determines the phase offset between each oscillator: the effect of the phase spectrum is more pronounced when several oscillators are tuned to the same pitch, so the effect of the phase spectrum is generally quite subtle in more complex sounds.

The integer and beating spectra work together to define the pitch of each oscillator. The integer spectrum can be thought of as a more coarse tuning value, with the beating spectrum providing finer control. The integer spectrum multiplies the base MIDI pitch by integer values from 1–32 as a means of easily tuning oscillators to precise harmonic ratios; this makes it easy to create harmonically pure, stable sounds. The beating spectrum, on the other hand, is a detuning control: it allows users to offset any oscillators’ pitches from their current “integer” values in order to access all of the inharmonic pitches between ideal overtones. This allows for much more complex, nuanced, evolving sounds…and even using these four spectra alone, a wide range of peculiar and novel sounds is available.


Dynamic Additive Synthesis

But there’s more to it than that—as I mentioned before, the Acxel is overridden with envelopes. And these aren’t your garden-variety ADSRs: they are 64-stage envelopes, each with user-definable hold and loop regions. As mentioned above, there are voice-level envelopes for controlling filter cutoff, FM index, amplitude, etc…but there are also per-oscillator envelopes specifically for controlling pitch and amplitude. Yes—there are roughly 70 envelopes per voice. Ordinarily, handling 70 envelopes would be an overwhelming and tedious feat; but as with the clever organization of spectra, Technos came up with a relatively efficient (and dare I say, almost intuitive) way of handling envelope settings.

Amplitude and pitch control in the Acxel can operate in one of two high-level modes: Fixed Additive Synthesis (FAS) and Dynamic Additive Synthesis (DAS). In FAS mode, amplitude and pitch values are determined by the spectrum values alone, but in DAS mode, the envelopes come into play. Users can switch additive synthesis modes and access envelope editing pages using the ISC (Intelligent Synthesis Cell) menu touch plates on the left of the Grapher’s touch plate matrix.

Envelopes are assigned to individual ISCs (the combination of one oscillator and amplifier) by using the Numeraline, the row of 32 touch plates immediately below the Grapher’s matrix. Once a cell has been selected for editing, its current envelope shape is displayed via the matrix LEDs: it can be re-shaped simply by swiping one’s fingers across the matrix surface. What is particularly interesting is that multiple ISCs can be selected for editing all at once—by selecting multiple ISCs via the Numeraline, it becomes easy to make broad changes in several cells at the same time. This removes much of the tedium in different implementations of additive synthesis, and makes it fairly quick to achieve complex, dynamic results.

DAS control of amplitude is fairly straightforward: it allows evolving changes in the concentration of particular overtones, providing easy access to continuously shifting spectral focus. There are two separate DAS modes related to pitch, only one of which may be used at a time: DAS-I, in which envelopes modulate the current Integer Spectrum values, and DAS-P, in which envelopes modulate the current Beating Spectrum values. DAS-I produces considerably more coarse pitch changes locked to harmonic ratios, often resulting in peculiar harmonic arpeggio-like effects. DAS-P, on the other hand, is an excellent way of introducing dynamic detuning, twisting overtones into constantly changing inharmonic ratios for sounds that shift from stable to clangorous and back again. By using intentionally-devised combinations of pitch and amplitude envelopes, the Acxel can produce remarkable variation across the course of a single note. (As a side note: in my personal experience, the Acxel excels at drawn-out, atmospheric/textural sounds…there’s simply so much possible within a single note that can too easily go unnoticed with shorter, more idiomatic “keyboard” sounds.)

As mentioned before, there are also per-voice envelopes for volume, filter cutoff, and FM index. All envelopes in the Acxel are 64 steps long, can range from hundredths of a second to half a minute, and allow the user to define a region of segments to loop when a key is held (using the Alphaline, a line of touch plates above the Matrix). What’s more, all envelopes utilize what Technos calls the Dual Envelope Concept: meaning that each envelope can continuously interpolate between two different, user-definable shapes. By using key velocity to perform this interpolation, for instance, the Acxel can be made to produce highly dynamic results which, in the best situations, can lead to combinations of character entirely impossible to predict.


The Tandem Problem & Resynthesis

The use of Spectra and the Acxel’s clever interface for editing envelopes does make for an uncommonly smooth and immediate additive synthesis experience—but it’s no secret that even this implementation is far from the ease of use of a Minimoog, for instance. Making good sounds from scratch can still take a considerable amount of time, cleverness notwithstanding.

Happily, the Acxel does offer another way of defining sounds: resynthesis. In many ways, resynthesis is the Acxel’s primary intended use case—or at least, that is what sales literature would leave one to believe. Technos saw this technique as a solution to some of the issues inherent in the then-still-maturing technique of sampling: namely, the issue they describe as The Tandem Problem.

The Tandem Problem is no doubt familiar to anyone who has used a traditional sampler. In samplers, pitch changes are often achieved by using playback rates different than the audio’s sampling rate. By playing back at rates slower than the sample rate, output sounds appear lower than the original sampled sound; by playing back at faster rates, the sound appears higher in pitch. This is great (and useful in a lot of situations!), but comes with an intrinsic, unintentional consequence: it also results in the sound being shorter as it increases in pitch, and longer as it decreases in pitch. This is the Tandem Problem.

Resynthesis is related to sampling, but a bit more complex in execution. In resynthesis, a source sound is recorded into a buffer and then analyzed (often via FFT or similar methods). The result of this analysis is a mass of information about the sound’s harmonic structure and how the loudness and pitch of its overtones change over time. The resynthesizer’s internal synthesis engine, usually comprised of a huge number of sine generators and amplifiers, interprets this analysis and utilizes it as control information, resynthesizing the sound through additive synthesis. The end result is a sound ideally quite similar to the input analyzed sound.

This has a huge number of advantages over sampling. The first is that the Tandem Problem is no longer a concern: since sounds are constructed out of banks of variable-frequency sine waves with pitch and volume contours defined by variable-duration envelopes, changing pitch doesn’t have to mean changing the duration of a sound (and vice versa). Changing pitch is instead just a matter of shifting all of the overtones by an identical musical interval (maintaining their harmonic relationship). Similarly, changing duration is just a matter of expanding or compressing all of the envelopes within a sound…pitch doesn’t have to change at all. This means that pitch and duration changes are both possible, and entirely independent of one another.


The Acxelizer

The Acxel achieves this process via the Acxelizer: a processor based on a simple AI that performs the analysis described above and assigns all of the most pertinent information within the analyzed sound to the voices’ Intelligent Synthesis Cells—ISCs, the combination of an Intelligent Digital Oscillator (IDO), Intelligent Digital Amplifier (IDA), Intelligent Pitch Envelope Generator (IPEG), and Intelligent Volume Envelope Generator (IVEG). The Acxelizer can even determine how many overtones are required to adequately reproduce a sound and “steal” resources from multiple voices to construct a single sound…which ultimately reduces polyphony, but enables the resynthesis of considerably more complex spectra, even including highly effective resynthesis of the human voice. Another interesting implication of resynthesis in this fashion is that it permits extensive manipulation of the sound, down to a much more atomic level than with pure sampling.

The Acxel maintains the same level of editing potential with resynthesized sounds as it does with purely synthesized sounds…so users can reach within a sound and modify the spectral profile, and the way it evolves over time. This is excellent for creating alien sounds from familiar sources, allowing the cadence of natural tones to influence the unfolding of otherwise impossible textures. You can quantize the natural inharmonicities in a sound to harmonic intervals; you can frequency modulate resynthesized sounds; you can accentuate weak overtones and de-emphasize strong ones. Being able to reach down to this level of detail in recorded sound is all but impossible…and this is what is meant by “Acxel”: it is an auditory pixel, the smallest unit of digital sound to which Technos provides you access.

The Acxel came with several 3.5″ floppy disks of presets: a host of synthesized and resynthesized sounds ranging from Moog-style bass to harp glissandi and loon calls. Some of these sounds are far more compelling/interesting than others…and while they are remarkable given the age of the instrument, some have “held up” better than others. Regardless, the instrument’s capabilities to synthesize complex sounds from the ground up are remarkable…and only otherwise possible at the time through similarly complex/valuable instruments such as the Synclavier.

Note: despite the name, not every Acxel necessarily contains an Acxelizer: the most affordable model at the time of production was the Acxel Stage, which could synthesize sounds from scratch or use preset “Acxelized” sounds created with another Acxel. British magazine Music Technology reported in their March 1988 issue that the Acxel Stage cost 8500GBP at that time. The Starter Studio, a basic system with Acxelizer, cost 14,545GBP; and the “top of range” system, complete with Acxelizer and maximum number of voices ran for 37,930GBP. EMEAPP’s Acxel is what, according to sales literature, was called the Pro Studio model, containing an Acxelizer and one Syncard (for a maximum of eight voice polyphony), with both a mixed signal output and individual outputs for each voice.


There is so much more to the Acxel. It is multitimbral—individual voices can be split, layered, or operate on completely separate MIDI channels. It has an analog lowpass filter for each voice, and a Variable Integer Pass (VIP) digital filter which allows you to hone in on specific Integers; there are LFOs (including an Intelligent LFO for translating vibrato in resynthesized sounds); you can even change the wave shape of the oscillators used for resynthesis…the list goes on.

But after getting to know the Acxel, it becomes apparent that it was never quite finished. Several front-panel controls do nothing; several sections of the user manual refer to “reserved,” incomplete functions; redundant editing pages make it feel as if features were planned, but never quite made it into existence. It is clear that Technos had big plans for where the Acxel was heading…and despite all they accomplished, it doesn’t seem as if it ever got as far as they might have liked. Later iterations were planned, but sadly none ever came to fruition.

Despite this, working with the Acxel is an amazing and rare treat…one that I hope I’ll have again in the future. It is a true rarity, and an ideal packaging of what was great about instrument design in the 1980s: designers were bold, and truly sought to create instruments unlike anything else that had ever existed. And, in this case more so than many, they succeeded.