The stuff of synthesizer legend, Keith Emerson's megalithic modular system hasn't just been restored — it's also been completely recreated.
When, on 1st April 2014, the news broke about Moog's recreation of Keith Emerson's iconic modular synthesizer, it's fair to say that most people dismissed it as an elaborate April Fools joke. But here I am in a small studio inside Moog's factory in North Carolina, sitting in front of Emerson's original synth, as well as the most painstaking recreation imaginable. For some players, it's possibly the most exciting analogue synthesizer project ever undertaken. Others will view it as possibly the most pointless analogue synthesizer project ever undertaken. But however you feel about it, you have to be curious about why Moog Music did it. And how they did it. And how well they did it. And, if you don't mind your studio being dominated by 400lbs of what is, in essence, a monosynth, what it will cost you to buy it.
To understand the background to the creation of this clone, now called the Emerson Moog Modular (or, for reasons that we need not worry about here, Roger The Synth), you need to understand that there was a time when all synthesizers were called Moogs, and Keith's instrument wasn't just a synthesizer: it was, for many people, the synthesizer.
I asked Keith how this came about and he told me, "In 1968 my band, the Nice, put out a single based upon Bach's Brandenburg Concerto #3. This met with a degree of success and, one day, the shopkeeper in a Soho record shop recognised who I was. He asked me, 'Have you heard this?', and put on a record. I remember asking, 'What the hell is that?', so he showed me the sleeve, which pictured a huge electronic contraption covered with knobs and cables and stuff. The record was of course Walter Carlos's 'Switched On Bach' and the thing on the cover was a Moog synthesizer, and I decided that I really had to get one. So I contacted Manfred Mann's keyboard player, a chap named Mike Vickers, who was one of the first musicians in the UK to own a Moog, and he loaned me his for a concert at the Royal Festival Hall. We were playing excerpts from Stanley Kubrick's movie 2001 — Thus Spake Zarathustra and all that — and the synth worked really well, although I suspect that everyone in the audience thought that its sounds were coming off tapes. But I was so impressed with it that, when I formed ELP in 1970, I wrote to Moog, hoping that I could get one for nothing. 'I'll endorse it and everything,' I promised.”
There's an oft‑repeated myth that Bob Moog responded to Keith by saying that his synthesizers were complicated pieces of studio equipment not suited to live performance, but it's wrong. By 1970, Herb Deutsch had been performing with a Moog for some time, and there's even a legend that, at one such concert, the synth's power supply started acting up, so Bob Moog dashed out, found two car batteries, and hooked them up directly to the DC rails of the synth so that Deutsch could complete the concert. What's more, the company had also built four performance instruments for a concert called Jazz In The Garden that took place at the Museum Of Modern Art in New York in August 1969. One was designed for percussion, one used some filters and other modules to process the signal from a polyphonic keyboard to make a primitive chordal synth, while the other two — one for bass and the other for lead lines — were expanded 1C cabinets with presets (called 1CA models) that allowed the players to recall some of the values of a sound by pressing a single button.
Keith picks up the story again, "I got a very nice letter back from a guy named Walter Sear, who was at that time Moog's East Coast salesman. He told me that, since the Beatles had bought their Moog and the Rolling Stones had bought theirs, he could see no reason why I shouldn't buy mine. So I did. I'm not sure that Greg or Carl were too happy about it, but there it is. After a while, a crate of equipment containing a disassembled synth arrived, so I set everything up on the table, and looked at it for a while. Then I looked at it some more. It took me ages just to find out how to plug the damn thing in, so I called Mike in a panic and said, 'You've got to help me with this.'”
Moog had shipped Emerson the 1CA lead synth from Jazz In The Garden without any documentation whatsoever. (Whether he knew that his new synth was, um, pre‑tested is something that I didn't dare ask.) Furthermore, the company rarely sold outside the USA, so there was no‑one on hand to support British customers. So Emerson took the synth to Vickers' house and left it with him for a week, during which time Vickers set up the patches that would become the bedrock of ELP's early output. Of course, the presets couldn't work without the correct cabling, so he also drew diagrams that showed Emerson how to connect this to that, and that to something else, so that the correct sounds would emerge.
Whether you view the rock of the early 1970s as some of the greatest music ever written, or as the worst musical excesses ever forced upon impressionable teenagers, it would be daft not to recognise that Emerson's use of the Moog was pioneering. But while the new genre of 'progressive' music to which ELP belonged was generally received ecstatically, this wasn't always the case. Keith reminisced, "In 1971, we were playing an open‑air gig in Gaelic Park in the Bronx. It was crazy. All around the field were trains shunting backwards and forwards, there were horrific, stinking portable toilets slamming open and closed, the Moog was screaming, and I was doing my thing sticking knives into my Hammond. Bob Moog was sitting just behind the amplifiers on stage, and when I looked around I could see that he was laughing his head off. But I later found out that another great musician, Gershon Kingsley (who had already recorded his own Moog records) was running around at the back of the field crying out 'Oh my God, it's the end of the world!' But we pushed on from there, and thank goodness we did.”
By this time, ELP had released Tarkus and Pictures At An Exhibition, so "pushing on” entailed recording Trilogy (1972), and what is perhaps the band's defining work, Brain Salad Surgery (1973). And, at every stage, the Moog grew to meet the increasing demands of its owner. Indeed, Emerson was not afraid to make it a tier taller just to make it look more commanding. If you now peer into its guts, you can still see that some of the modules are dated 1960‑something, while others are dated 1972 or later. With a bit of detective work, it's not hard to discover which were added for Trilogy, which were added for Brain Salad Surgery, and even to identify those that were replaced later in the 1970s when something failed. So, what had started as a single cabinet that you could carry under one arm eventually grew into a 400lb behemoth, with dual sequencers, additional oscillators, filters, amplifiers, contour generators and LFOs, and even some dummy panels to fill up the cabinets and make the resulting instrument look as imposing as possible.
By this point, Emerson's synth was no longer a single synthesizer, because he had patched it so that various modules could be used for specific tasks. This was a necessity; he couldn't re‑patch it during the show to create new sounds, because his audience expected him to play tracks such as 'Tarkus' and 'Lucky Man' at some point in the proceedings, and the patches he used for these were both distinctive and complex to create. So, while there were myriad more things he could have done with the existing modules, he had to modify and add to the system when new sounds were needed. For example, switches were added to inject audio and control signals from new modules into the 1CA panel that still provided much of the primary signal path, while a dedicated sequencer, oscillator, filter and various contour generators and VCAs were added to generate the sequence that ends 'Karn Evil 9'.
Unfortunately, following ELP's heyday from 1970 to 1977, the big Moog fell into disuse, and many stories (some true, many somewhat less so) abound about its mistreatment throughout the 1980s. But in 1991, ELP reformed to tour and record a new album, Black Moon. Gene Stopp was Emerson's synth tech at that time, and he continues the story: "The Moog was in very poor condition when I first got hold of it, and although a partial repair got us through the Japanese tour, a much more thorough restoration was necessary to make Black Moon and In The Hot Seat possible. I then withdrew to bring up my family, and it was to be almost 20 years before I was reunited with the synth. Meanwhile, it had been in the hands of people who knew nothing about synthesizers but had been trying to work on it. Moog even received a call from somebody who asked 'Which modules are the oscillators?' I hope that whoever took that call suggested that the ones with the word 'oscillator' on the front panel might be a good place to start. In truth, it's not that complicated a system, but you need some experience to understand it and track down faults.
"You have to realise that customisation lies at the heart of Keith's synth. If you were able to track down all of the modules that appear to exist within it and then set up the patches that he appears to use, you'll find that very different sounds emerge. Take the vibrato switch. This doesn't sound like an important modification, but it was never an original Moog feature and Keith needed it, so it was added by Moog's engineers, who used it to switch in an extra oscillator, amplifier and contour generator to produce delayed vibrato. When customising existing modules didn't do the job, new ones were built: things such as the tuner that allowed his roadies to retune the 1CA's oscillators even while he was playing the synth and, in particular, the unique 'Keith Emerson Sample‑Hold Module' that sits to the right of the middle cabinet and is necessary to produce the iconic 'Welcome Back My Friends' sound on Brain Salad Surgery.
"As a result of all of this, large parts of the synth were non‑functional when I took delivery of it again three years ago, but Keith was happy for me to work on it at home, which meant that I could devote much more time to it than I had in '91/'92. While I was doing so, Brian Kehew (who has served as the Archives Historian for the Bob Moog Foundation) and I started to question why some of the panels needed to remain empty or non‑functional, so we added some extra LFOs and other options that we thought Keith would appreciate. But we remained very much aware that he still needed to be able to switch immediately to, say, the 'Aquatarkus' patch. This originally disconnected two of the 1CA oscillators from the keyboard to create a drone, restricting him to soloing using just a single oscillator. We thought, how cool would it be to add a switch that turned on two dedicated oscillators, a filter, an LFO and some other modules to create the drone without sacrificing the main oscillators? So we did, and you can now get sounds and effects from the synth that nobody's ever heard before. But while working on this, we began to realise that Keith's synth is like a Stradivarius of the modern era; it needs to be preserved for posterity. You've got to understand that it's not like replacing a broken Minimoog. If you want one of those, you just go out and buy one. If you want to replace Keith's synth, you can't. You can't even replace bits of it. I tried to buy some spare modules, but they simply didn't come up for sale, which meant that there were going to be huge problems in the future if any of the original units were to become irreparable.”
Kehew (who is also well known as a musician and engineer for the likes of the Who, Black Sabbath, the Eagles and Yes) had reached the same conclusion, but from a slightly different direction. "The idea of restarting production of genuine Moog modules had existed for years,” he told me, "but there were already companies building versions of them, so it wasn't obvious that they would generate much interest. Then we realised that we were working on the best‑known synthesizer in the world. We thought about the Moogs used by other artists — Giorgio Moroder and Wendy Carlos, for example — but none of their synths evoke the same awe as Keith's, because no other instrument has been so visible for so long. While other players were replacing their vintage synths with modern equipment or even laptops, Keith continued to use his and, while it isn't the be‑all and end‑all of synthesis, it remains the most revered synthesizer that there ever was. So Gene and I realised that, if we could reproduce the modules from Moog's catalogues in the '60s and '70s as well as the unique modules that had been built for Keith's system, we might be onto something really exciting. Could we go further and clone Keith's synth? With the 50th anniversary of the creation of the first Moog synthesizer approaching, it seemed like the perfect time to see if we could make it happen.”
Their first job was to track down Moog's old manufacturing documents, such as layout films and service manuals. However, this proved merely to be a step along the way, because the original systems had been built by people who knew what tweaks were necessary to make things work, and much of the additional 'know‑how' wasn't documented. But Kehew proved to be the Indiana Jones of the synthesizer world, and he tracked down all manner of bits and pieces making up Moog's legacy: a film for a circuit board or front panel here, a naked circuit board there, pages of scribbled notes about modifications that never made it into the company's library somewhere else. He and Stopp collected everything that they could, and eventually reached the point where they felt ready to approach Moog Music's management to propose building a 'proof of concept' instrument.
Moog had already given Stopp permission to build a small number of the modules that, to this day, hold Emerson's presets. (At one time, there had been seven of these in the synth, but by the time that he took delivery of it in 2011, only five remained. No‑one seemed to know what had happened to the other two, but one thing was clear: should another fail irreparably, it would make it impractical for Emerson to perform some ELP tracks.) Consequently, it was perhaps unsurprising that Moog gave Kehew and Stopp a tentative 'go‑ahead' to develop a complete synthesizer.
The next stage was to assemble some test boards and panels. Using a 921B oscillator as a guinea pig, they ran into an unexpected problem. The electronics were fine, but different incarnations of the front panel came out a bit too shiny, or with a bit of a purple tinge, or were a bit too black when compared with the originals. But finally, after numerous attempts, they got it right. It was a key moment; they weren't just in a position to manufacture new modules, they were in a position to make accurate clones of the originals.
Nevertheless, there were to be numerous additional hurdles as they attempted to clone the whole synth, and it proved to be the seemingly trivial stuff that caused the biggest problems. Panels could be punched and printed, and even obsolete chips could be found in surplus stores. But the biggest headaches came from the red, green, white and blue switches that route the signals within the original synth. These had been discontinued in the 1960s, and although Stopp found a supplier who had some stock, they all had red actuators. So he bought a number and took one to a 3D printing company, together with examples of the actuators from Keith's synth, and asked whether they could replicate the correct colours and degrees of translucence. Astonishingly, the printers were able to do so, so Stopp bought the rest of the switches, and another problem had been overcome. Similarly, Stopp and Kehew had to find a way to replicate the fire switch in the top left‑hand corner of the synth. Although it's not a synthesizer module (it was a gift that was mounted on a panel because Emerson thought that it looked cool) it had become a significant part of the synth's image, so they approached a machine shop that was prepared to manufacture a replica.
Another thorny issue concerned the new synth's power supply. Those installed in early Moogs were designed to power single- (or, at most, dual-) cabinet synths, and no‑one had expected them to be used in something as large as Keith's instrument. What's more, since the aim in 1965 had been to push the boundaries of sound rather than to play semitones in perfect tune across five octaves, the acceptable degree of instability was far greater than when synths became primarily soloing instruments just a few years later. So a decision had to be made: should the clone have an original PSU with all of its limitations and instabilities, or should it incorporate a new design that could power the instrument comfortably? Eventually, the decision was made to install a modern unit that would provide the correct power no matter what loading was placed upon it.
Finally, there was the metal shell that protects the synth while on the road. To reproduce this, Kehew and Stopp approached a racing-car welding shop that they found on the Internet, took them some drawings and asked, "Can you make one of these for us in under two weeks?” To their surprise, the answer was 'yes'. They then had to get permission from Moog's management to incur the extra cost and were surprised, again, to be told, "While you're at it, get three made.” Clearly, Moog Music were now committed to building at least one replica, and considering more, so work proceeded with the target of having the first synth ready in March 2014.
I asked Kehew how much leeway they had been prepared to allow themselves during this phase. "With the exception of the power supply, very little,” he told me. "The whole concept was that the replica had to be almost indistinguishable from the original — not only the sound and the appearance, but even the feel of each knob and switch, the feel of the metalwork... everything. We knew that we might have to change something if it was the difference between the project being possible or not, but we hoped that we wouldn't have to do so. Ultimately, this was a proof of concept assembled to determine just how close we could get.”
Despite the original deadline having passed some weeks before, Roger The Synth was still a work in progress when I arrived at Moog Music on 16th April, with a handful of modules being populated and fine‑tuned to achieve the desired performance. I asked Stopp how close he felt it was to the original. "At the moment, it's more than 90 percent there,” he told me, "but in the next week, without too much effort, I should be able to make it 100 percent.” I then asked whether, allowing for component tolerances, he truly believed that the two would sound identical. "Yes, without reservation. I suspect that the only difference will be that the clone will be more reliable. It has fresh wiring, fresh solder joints, and knobs and switches that haven't been used for up to 40 years. Otherwise, it should be indistinguishable.”
Nonetheless, I wasn't surprised when I uncovered numerous minor faults as I tested it. For example, the main filter glitched. There was no apparent reason for this, but Stopp tracked it down to the sample & hold module, which was leaking a clock pulse into the wiring loom. Usually inaudible, this became apparent in a simple trumpet patch that I had created. Once identified, the problem was fixed within a couple of hours. Another fault involved a popping sound generated when one oscillator was clamped (hard‑sync'ed) to another. Again, Stopp tracked it down and devised a solution. Other unexpected results were also identified, resulting in numerous modules being whipped out, only to be returned a few hours later. I even identified a glitch on Emerson's own synth, which was caused by a clock retriggering a ramp generator in the drone synthesizer. You might ask why these problems only came to light when I arrived, but there is a sensible reason; Emerson's synth had been patched the same way for years to carry out a particular job, and Roger had up to that point been tested only against those sounds. Nobody had had the opportunity to test the modules in a more analytical way, creating sounds that Emerson himself had probably never tried.
Happily, once the glitches were eliminated (and they all were) Roger was in fine shape and I could think about reviewing it. But how? Sure, I could set up simple sounds on both synths — say, something as basic as one oscillator on each directly to the output mixer — and when I did so, I found Stopp was right... they sounded all but identical. I could also patch both synths to create the complex sounds used by ELP, whereupon I found that I could jump between the two without a break, leaving most listeners unaware that I had done so. But while these exercises told me that the new instrument was genuinely what it claimed to be (ie. a clone) it still doesn't help me to tell you how it sounds. Maybe I could save a few hundred words by writing, "listen to Emerson Lake & Palmer's live albums. It sounds like that”. But, of course, Emerson's sounds are just a snapshot of its capabilities. Roger is a huge modular synth that can perform myriad tasks that Emerson never asked of it, and myriad more besides. So I came up with (what I hope was) a neat solution: since I was in Moog's factory and had access to every synth they make, I compared Roger to the company's flagship Voyager XL. I am a big fan of the XL, and with good reason; it's beautiful, it has a five‑octave keyboard, it's a joy to play, and it can sound excellent. But when I placed it next to the modular and set up the lead sound for 'Lucky Man' on both, the XL continued to sound excellent, whereas the modular sounded incredible. Likewise for the detuned 'fifth' sounds that Emerson uses for tracks such as 'Hoedown' and 'Tarkus', and almost anything else, nothing made the XL sound quite like the modular. How can I describe the difference? Weight? Authority? Power? All of these words are appropriate, but perhaps the most meaningful word that I can use to convey my feelings is to say that Roger simply sounded bigger.
Part of the reason for this lies in the Moog 905 spring reverb module (see box). The more that I played the synth, the more I realised how much of its character derives from this, to the extent that it wouldn't be the same instrument if you took it away. Sure, you can add a suitable reverb to the Voyager XL (or, for that matter, anything else) but it just doesn't sound quite the same.
Of course, there has to be a cost, and there is: noise. Moog's modular designs hail from a bygone era when such things were rather less important than they are today. When I mixed the Keith Emerson Band at Moogfest, one of the first things that I had to do was put a gate across Emerson's Moog. Meanwhile, Stopp was busy building an acoustically damped enclosure for the spring reverb tank and soldering a set of extended leads so that it could be placed in another room to avoid the howling feedback that accompanied almost any significant level of signal passing through it. The clone is no different so, if you're expecting it to have a digitally clean signal path, forget it. This thing molests every sound passing through it, distorting it in all manner of subtle ways and adding small amounts of noise at almost every turn. But the defects tend to add to, rather than detract from, the character of the result. As lead guitarists from the 1960s onward have discovered, coloration isn't necessarily a bad thing, and purity isn't always the goal.
If all of this sounds like the ramblings of a star‑struck teenager, please be assured that it's not. Minimoogs are great, ARP 2600s are great, Memorymoogs, Rev 1 Prophet 5s and Yamaha GX1s are great, digital synths such as the Korg OASYS and the Kronos that Emerson uses nowadays are great, and I love them all, but none of them sound like Emerson's Moog Modular. Furthermore, there's nothing quite like having the instrument under your fingers. While there are some excellent software emulations of vintage synths out there, they're still not the same as playing the originals. So if you're thinking of offering the insane amount of money that would be necessary to prise Roger from Gene Stopp's clutches, you can be assured that — whatever people might think of you, and to whichever institution they might try to have you committed — you'll have an instrument that feels and sounds like no other, except, of course, for Keith's own synth and any other clones that Moog might choose to manufacture.
Sometime in the early 1970s, something important was lost. The early synthesists were genuinely pushing the boundaries of sound, not limiting themselves to generating the next squelchy bass line that sounds almost indistinguishable from the previous thousand squelchy bass lines. And, more than anyone else outside of the avant garde community, Keith Emerson was pushing those boundaries, attempting things that nobody else even contemplated. Sure, by 1973 everyone was soloing brilliantly, and dexterity with pitch‑bend, modulation wheels and aftertouch was de rigeur, but Emerson's sounds were far more aggressive and interesting.
Consequently, it has always been my dream — and that of many other players — to own the sort of synthesizer that made this possible. But on the very, very rare occasions that one has become available, it hasn't necessarily contained the right mix of oscillators and filters, or maybe it had too few VCAs and contour generators, or no LFOs or... well, you get the picture. I was always aware that I could say a tearful farewell to a huge wodge of cash, and never have the opportunity to buy the extra modules, cabinets or power supplies that would make the synth do what I wanted. So I never bought one. I might be a fan, but I'm not stupid.
But today, Moog Music have demonstrated beyond doubt that they are capable of rebuilding their modular synths. Although Roger's birth was orchestrated by Kehew and Stopp (who ensured the historical accuracy of the new modules and took care of the technical details, respectively), many people at Moog's factory in Asheville contributed to its creation: so, whether you want to buy a convenient 1P or System 10, or a mighty 3C or System 55, it's likely that they could now build it for you. And if you want something configured and customised for your own needs, that could also be done. A system with six sequencers and no keyboard? Why not? A system with no oscillators but all manner of filters and modulators for mangling external signals? Again, why not? The metalworkers and joiners who built the shells and cabinets, the printers who recreated the switch actuators, and the machinist who recreated the unnecessary fire switch that does nothing but look good... together, they have shown that it can all be done again. So, amazingly, the next few years could prove to be the heyday of Moog Modular synthesizers. If you ordered one in 1968, you couldn't buy a sample & hold module for it because it didn't exist; if you ordered one in 1978, you couldn't buy a 901 oscillator because it had been discontinued. But it's quite possible that a future catalogue could contain all of the modules from Moog's history, including the special modules and custom modifications that were developed along the way.
Of course, this presupposes that the engineers at Moog Music are going to start building vintage modules for general sale again, and that's not a foregone conclusion, not least because their electronics predate modern safety standards and the ROHS (regulations on hazardous substances) legislation of many countries. What effect conforming to modern standards might have on the modules themselves — whether sonically or in terms of physical appearance — only time would tell. So the decision‑makers will have to ask themselves whether new designs would still be considered 'vintage' Moog modules, or whether that even matters. Mind you, were Moog to restart production, who's to say what new modules might appear to complement the vintage ones? But for the moment, the official line remains that the future hasn't yet been decided, and I don't think that's evasion.
So, for the moment, the only synths on offer are the three additional Emerson Moog Modulars slated to be built later in 2014. If you're tempted to buy one of these, I suppose that you might like to know what it's going to cost. But, as Rolls Royce salesmen in the 1960s were heard to say, "if you have to ask, you can't afford it.” A figure of $90,000 has been bandied around. I suspect that, once everything has been totted up by the bean‑counters, the final figure might be higher, although, if you extrapolate the prices from the very rare sales of smaller Moog Modulars over the past decade or so, it may not be too wide of the mark. On the other hand, a synth built in 2014 doesn't have quite the same cachet as a similar one from the '60s. On the other, other hand, anyone who buys one of these will not only own a fabulous musical instrument, but what is likely to be an appreciating asset. As for Roger The Synth himself, he'll be going back to Stopp's living room in LA, where he will become the world's best talking point over afternoon tea and scones, as well as a backup for Emerson's own synth.
In the end, it was a huge rush to finish Roger in time for Moogfest, and I doubt that anyone has yet had time to draw breath and evaluate the response to it. Cynics might dismiss it as a gimmick, or merely a marketing tool: not so much an instrument as a collectable. And you know what? They would be right. But that's irrelevant. Forget Keith's iconic system, forget ELP, forget Switched On Bach, ignore the history, and ignore the fact that Moogs look and feel great. If you walk into a room containing a selection of synthesizers and play each of them, there's something compelling about the sound of an early Moog Modular that sets it apart from everything else. Consequently, I suspect that demand for the handful of clones slated for production will outstrip supply, even at $90,000. For those with the money, somewhere to put it, and the willingness to maintain it, an Emerson Moog Modular will be a dream come true. As one senior, but nevertheless awed, Moog employee sighed as he walked past the one I was playing: "so damn cool”.
My thanks to Mike Adams, Emmy Parker, Trent Thompson, Brian Kehew, Gene Stopp, Charlie Green, Mari Kawaguchi, and of course, Keith Emerson for their assistance in making this article possible.
The name 'Emovision' was probably coined when Gene Stopp and Will Alexander were restoring Keith's synth in 1991 prior to the recording of Black Moon. From the beginning, there had been some sort of display in the upper right-hand corner of the synth. Originally, it was a frequency counter used to tune the oscillators during the show, but this was later replaced by a small colour television (still a relative rarity in the early '70s) with an early video recorder tucked away that played tapes with waveforms and special graphics on the screen. Nothing was synchronised to what the band was playing, but it looked good and was just another element in Emerson's showmanship. A third incarnation drew fake waveforms using a matrix of little red lamps, but it wasn't bright enough and became progressively dimmer as the waveforms increased in speed.
During the most recent restoration, Kehew suggested to Emerson that they install an LCD screen in the same location and recreate the 1970s graphics on DVD. Strangely, Keith's first question was, "Will it show pornography?” This isn't as odd as it may seem. At one of ELP's gigs in the mid‑'70s, the road crew replaced the tape containing the waveforms and graphics with an early porn video. Sometime during the gig, the front rows of the audience started cheering and pointing, and Emerson has since admitted that he thought he must have been putting on one hell of a show. Who knows, perhaps the band was playing 'Still You Turn Me On' at the time.
In the late 1960s, the Moog 905 Reverb Module installed in the 1CA used a short spring-reverb tank mounted behind its panel, but legend has it that ELP's sound engineers hated it and, for whatever reason, it disappeared a long time ago. By the time that Stopp received the synth, somebody had modified the electronics so that an external tank could be connected, so he scavenged a unit from an old PA system and, on plugging it in, was surprised to find how good it sounded. So he bought a couple of 17‑inch Accutronics tanks and fitted one of them to Keith's synth and another to the clone. These sounded even better, adding animation and coloration to the sound, and I suspect that something similar had been done in the early '70s, because the character of Emerson's synth is again very similar to that of classic ELP.
But increasing the length of the reverb springs is far from the whole story behind the 905 in Keith's synth because, as originally designed, it had a mix control that ranged from a totally dry signal at one extreme to a totally wet one at the other. Strangely, as soon as the reverberated sound was mixed in, the synth lost some of its low‑end power and its crystal‑clear high‑end. Happily, a simple solution was found. Instead of reducing the amplitude of the source signal as the reverb was added, Stopp and Kehew realised that they could modify the module to make it add the reverberated signal without diminishing the original. Apparently, this took just a couple of minutes, and the module now works as I suspect that it always should have done. The synth now retains all of its power while adding the reverb on top to create that instantly recognisable 'Keith Emerson sound'.