The "Kraftwerk" Polymoog (SN 3247):

Stefan Bornhorst (Hamburg, Germany) Jul 2006


Greetings from Hamburg, Stefan.

The story starts in 1993. A bit younger then, equipped with some musical ideas, a little knowledge about analogue synthesis and a Korg MS-10 but not much money in the pocket, I wanted to get a polyphonic synthesiser. Matthias Becker's book "Synthesizer von gestern" was my 'bible' and in that book was an article about the Polymoog which said it was a great synth but didn't cost too much on the 2nd hand market. Unable to finance one of the really expensive "flagships" like a Jupiter8 or Prophet5, I finally found a Polymoog 203A offered in an advertisement from a vintage synth dealer in Cologne, more than 500 kilometres away from Bremen, my hometown. But it cost exactly as much as I was able to pay, so I decided to make that trip and after about 5 hours of driving on a cold and rainy Saturday morning in February I arrived in paradise!...


The shop had just opened its doors (it was about 10 in the morning) and they had simply everything. ARP 2600s, a Multimoog, a Memorymoog, even one of the last 25 Minimoog’s, just to name a few. And among all that old machinery was the Polymoog I wanted. It was all black outside - the "wooden" pieces on the top had been removed, the Moog logo on the back was missing, it had no legs, there were semi-professionally-drilled holes in the top lid, and I was not able to afford the Polypedals as well. But nevertheless I bought it. When I brought it to my car together with the guy from the shop, the guy somewhat mysteriously told me that this Polymoog (s/n 3247) had been previously owned by "Germany's most famous electronic band". "OK, then it must have been Kraftwerk or Tangerine Dream".


"Kraftwerk" was the reply.

That didn't really make me nervous at first because although I've been a big synthpop fan at that time (I still am) I never cared much about Kraftwerk and didn't own any of their records, but I opened up the Polymoog when I was back home to look for a name plate or something like that. I didn't find a name plate but some stickers from the once-famous "Synthesizerstudio Bonn" and some custom potentiometers with hand-written stickers above them that told what the pots were doing. So I considered the Kraftwerk story to be true and bought "Die Mensch-Maschine" some days later because I felt that if I own one of Kraftwerk's synthesisers, I'd have to own at least one of their records as well. And I was immediately hooked to that record. I couldn't stop listening to it...


Here is a video of Kraftwerk from their 1981 "Computerwelt" tour where Ralf Hutter is seen quite clearly playing "Stafan's" old Polymoog 203a for the lead line. Also in the clip you can see his Minimoog on top (all instruments being stripped of brand-names and wood of course to emphasise the INDUSTRIAL look required by the band.

Download Video (Div-X AVI) >>>





The Polymoog was a different story. I felt that it sounded by far not as big and fat as it looked and there seemed practically no way to make it sound "bigger". It seemed to be quite complicated to use as well, compared to my only other "real" synth, the MS-10. The only other keyboard I owned at that time was a strange analogue string/multi keyboard from Elka called "Elkatwin 61" which is fully polyphonic, has two groups of preset sounds that can be detuned against each other, then put through one of the two separate chorus/ensemble circuits (or both) and on top of all there's of the most beautiful phasers I've ever heard. To cut a long story short: This was a really MASSIVE sound compared to what I got from the Polymoog although I was always stuck with the Elka's few presets... The situation got even worse when I got a new toy, a Mellotron, in the summer of 1993 (instead of going on holiday that year). This seemed to be much more interesting and so the Polymoog was gathering dust in a corner for about a year before I took the time to play it again one weekend. What happened then is something I still remember very well: I don't know why, but I had never turned up more than one slider on the mixer. This time I did it - I turned up the VCF (the attack time of the VCF envelope set a bit above zero), turned up the "Direct" slider a bit as well and what came out of the Polymoog then blew me away. "Pheeaaoouuw!" It was exactly the lead sound from Kraftwerk's "The Model" that I found by accident, and it was the beginning of a real love affair. I cancelled everything I wanted to do that weekend and started a belated discovery tour. There was quite a lot I discovered: First of all FREEing the VCOs from sync is a very good idea, the resonators are a wonderful tool and great phasing effects can be achieved when more than one slider on the mixer is up. From today's point of view it seems really strange to me why I didn't find out those Polymoog basics immediately. Maybe the step upward from the MS-10 to the Polymoog was a bit too big at first...

So then, I ended up being not only a big fan of Kraftwerk but also made great friends with their (ex-) Polymoog. A friendship that sadly was not to last longer than six years. The beginning of the end was in 1998 when the Polymoog started to put out a very high pitched tone (about 16kHz) that became tiring to the ears when I played for more than half an hour. So I took the Polymoog to a tech who worked at a local organ shop, got it back quite soon and it worked. But some weeks later the high tone came back, followed soon by a clearly audible distortion especially on the higher notes. After some months of simply avoiding to play higher notes, I took the Polymoog to the only other technician I knew who was working at a local music store. When I got it back after more than a month, the high tone and the distortion were gone but just to come back after two days! And while I was still thinking what to do next, it broke down. Totally. No sound at all anymore. The LEDs and switches first looked as if they worked but soon they gave up, too. Cleaning of the contacts of all the cards and connectors followed but that didn't work. Reluctant to give the Polymoog to one of the local technicians again, I finally rang up the highly respected Moog specialist Rudi Linhard. But Rudi didn't want to help, he told me that he wouldn't even touch a Polymoog. So that was the end. When I decided in 2000 to sell my Minimoog because I felt I didn't need it anymore, I sold the non-working Polymoog as well, both to a guy called Jens (aka "Polymoogie" in the Polymoog Owners Club). After the transaction we stayed in contact and became great friends (we still are), so at least that was the good thing about selling the Polymoog...

After the Polymoog had left my flat, I started to look out for a reliable replacement and finally ended up with an Access Virus A which was in my opinion the most analogue-sounding modern synth at that time. I must admit that I was quite happy with the Virus for at least two years - it never broke down, it always did what it should do, it was continuously updated with new functions for years and it sounded analogue-ish. But although I never missed my Minimoog for even a second, I started to really miss the Polymoog and each time I visited Jens I ended up playing one of his Polymoogs for hours. Especially my ex-Polymoog which Jens had got repaired for next-to-nothing by the tech guy from the organ store! Those were the moments when I felt that something went wrong with my life...

Meanwhile, "thanks" to Ebay, Polymoogs got more and more expensive and because of that it became a definite "no" for me to get one this way. But after some more years of Polymoog-less misery, Jens offered his Polymoog no. 1144 to me last summer. He told me that this one was working but the least reliable of the bunch of Polymoogs he had, so he offered it to me for the same price that he had paid for my non-working Polymoog five years before. A really fair deal from good ol' Polymoogie and of course I DID buy it! By then my frustration with all that pseudo-analogue machinery had reached a point at which it seemed better to have a totally unreliable Polymoog than no Polymoog at all. The good thing about this is that this time I was prepared. I even made a guess how long it would work before the first breakdown! The guess was six weeks. I was wrong.

I came home together with the Polymoog that was mine now at about 5 one sunday morning in summer 2005. Too early to ask my neighbours to help me carrying it but as I didn't want to leave it in the car, I carried it upstairs alone and although my back was aching badly after that I plugged it in immediately. There was that sound again: "Pheeaaoouuw!". One or more octaves up the keyboard, the sound was accompanied by a "brzzzz". Not only was that sound finally back at my home, but also that distortion! I immediately took up my "avoid the high notes!" technique from years ago again and was happy for the time being. About three weeks later I got an MAM RS3 resonator bank. It seemed a good idea to check that one by putting the Polymoog's sound through it, so I plugged the two together and the sound was simply brilliant - at first. But after about 10 minutes the Polymoog started to put out some heavy crackling noise, the sound got quieter and quieter before it completely died, the LEDs started to flicker, there was no reaction to the VAR/PRE switches anymore... and then it was gone. In the following weeks I tried again and again but apart from a very quiet sound (sometimes) and some flickers from the LEDs it had nothing to say to me.

So it took three weeks to break down, not six. Maybe I had been too optimistic. And maybe it was a mistake to put that little 19" unit on top of the Polymoog, right above the power supply, on a warm summer day. Whatever happened, I had to face the fact that I had a broken Polymoog again... Some time later I talked to a friend of mine who is a big fan of analogue synthesisers as well and he suggested to take it to a tech called Peter in Hamburg who is an engineer in electronics and supposed to be a real specialist in analogue synthesisers. I finally did that and when I appeared at Peter's workshop, the first thing I got to hear from him was that he didn't like the Polymoog because it was the most simple divide-down circuitry ("like a Bontempi organ!") in a badly constructed and over-complicated package. Bang! :) But we talked a little bit more and Peter told me that he was just customising a Korg MS-20 with a self-constructed midi in/out interface that is able to send and receive controller data for all knobs and has master keyboard functions as well. He also told me that he had just done the same to the Polyvoks that was waiting in a corner, but writing the software for the MS-20 interface was a more difficult job because the ROM chip only had 512k... I was impressed to say the least, so I left the Polymoog there.

After a week I got a call from Peter: He had just opened up the Polymoog to check it but it worked! I couldn't believe that, so he asked me to come round and check it myself. When I arrived, he had already done an in-deep check and discovered that the distortion was still there. It was interesting to view that on the scope when only the rectangular wave was on: The rectangle had a clearly visible "peak" before the line went horizontal. He had already checked the Faratron PSU as well and showed me that most of the parts had a much higher temperature than they should usually have. Also, the Faratron's output was more than unstable so that there was a lot of noise in the circuits which could be the reason for the distortion. Peter suggested that he would build a custom PSU for my Polymoog because he felt anxious to work on the Faratron PSU which some "non-professionals" had worked on before. I said ok and the final deal was that I only had to pay the full price if his new PSU would kill the distortion - otherwise the price would have been split in half. Nice!

Two weeks later I got another call from Peter: The new PSU was ready but he was not really sure about it. So went to Peter's again and was blown away, again... No distortion anymore, everything was crystal clear up to the highest note! And how nice and clean that new PSU looked, compared to that old Faratron thing! That was a really happy day although I had to leave the Polymoog at Peter's because in the meantime he had found some other small issues like a loose transistor etc.

But some days later the Polymoog was ready to come back home again. A friend and neighbour of mine helped me to carry it upstairs, we set it up and it sounded better than ever before so that I immediately planned to record a whole LP just with the Polymoog! A really nice plan, but it was disturbed after five minutes of playing by a distortion from the sawtooth VCO that was worse than ever before! I switched off the Polymoog and off we went to my neighbour's flat to have a coffee.   I had to get some different thoughts into my head. But when nobody was looking, I returned to my flat, switched the Polymoog on again and the distortion was gone! That was something I had never experienced before - if the distortion was there it was there to stay. I played it for 20 minutes and nothing changed, so I left it switched on and happily returned to my neighbour's flat for another coffee. When I returned to my flat again, everything looked fine except for the beat LED which was alight but did not flicker anymore. And there was no sound at all, a situation I had become familiar with.         So I switched the Polymoog off, went back to my neighbours and changed from coffee to beer.

The next morning I had the idea that there must be overheating problems with the new PSU. The day before I had already noticed that the Polymoog did not become as hot anymore as it did with the Faratron PSU but it was still quite hot on the back. And Peter, logically, only worked on it with the top lid taken off. So I took off the top (of the Polymoog) as well and left it switched for about 10 hours. Everything worked! After some experiments I found out in the following weeks that there's enough air circulation in it when the lid is only a bit open - I simply left the screws removed and put two crown caps under the lid so that it's lifted up by about 1/2 centimetre which is better than drilling holes into the lid like the Kraftwerk guys had done. That seems to be final solution, the Polymoog has its new PSU now for about two months and has turned out to be absolutely reliable since then, even in those hot summer days we have at the moment and even though it has the lowest serial number in the list. The only problem was some quiet crackling in the resonator section that I didn't even notice that first because it sounded like a firework outside (there's a lot of fireworks in Hamburg in the summer and I had put the Polymoog through a long reverb...). After I switched it off and on again, the crackling was gone and didn't come back.

So, after all these years the Polymoog finally became the centre of my little studio again. I play it every day when I come home and on the weekends it normally stays switched on from the first coffee in the morning to bedtime so that I'm able to play a chord when I need one of these chords... and that's often the case! A wonderful synth, I don't think I'll ever get to hear one that I like more...

On behalf of all of us at the Polymoog Owners Club, I'd like to thank Stefan for his story (so far) - cheers =o)