Jim Scott on working with Bob Moog

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 visiting 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)


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.

Glossary

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.