A Guide to Buying a Secondhand Analogue Synthesiser

We get a lot of phone calls along the line of … “i’ve seen a XYZ synth on Ebay/local ads, is it a good buy, what should I look out for?” and even crazier questions like…
“I have seen a Prophet 5 on Ebay with no voice card, how much will it cost to repair this?”

Almost all of the desirable analogue synths are about 30 years old and spare parts of almost any kind are proving more and more difficult to acquire as the years go by.

So our viewpoint is…

Never buy a synth with missing circuit boards… even if you can find them, several limbs will have to be sacrificed. Some synth circuit boards have almost become a commodity on Ebay, including Oberheim OBxA voice cards, and also voice cards for the Rhodes Chroma, the Jupiter 8 and the Memorymoog. These cards are getting scarcer by the month and their cost is now running into hundreds of Euro per card. All of the above voice cards contain valuable components that are worth even more than the purchase price of the whole card.

Another point of note is that if the synth card is for sale, then a synth was broken up to supply it and we can’t condone this practice. The breaking up of old analogs and parting them out piecemeal is becoming more common in recent times, and unfortunately, to use an example, a Roland Juno 60 is worth more in parts than the complete synth.

Any other circuit boards are going to be almost impossible to get, you’ll have to monitor Ebay for a long time in the hope that what you are looking for will turn up and then you have to win it and pay for it.

Do not buy the battered and beatup if you want a pristine result, a lot of modern buyers want perfection but a battered chassis will be either impossible to fully restore or more expensive than buying a decent model in the first place.There are companies that can replace the entire wood frame of certain synths, but this can cost several hundred Euro, likewise there are companies who can refinish scratched and damaged metalwork but this is also expensive.

Other items of hardware to check are ones specific to the synth. This includes broken sliders/pots missing switches, missing switch caps,missing knobs, broken pitch bend/ mod wheels and broken output sockets.

Certain brands of synth are reasonably well catered for by manufacturers who have cloned the original parts. These clones are reasonably priced and are as good as the originals, especially when the originals have been unobtainable for more than a decade. As for the rest, the available stocks of the synthesiser parts specialists are diminishing by the month.

A couple of synths are infamous for their major failings, the Roland Juno 106 and the Korg Polysix.

The Juno 106 was the MIDI capable update of the Juno 60, it has a great MIDI spec. for the time, and it sounds very good. The downside is that to save space on the voice circuit board, Roland integrated the Filter and output VCA from the Juno 60 into a module built with surface mount components mounted on a ceramic circuit board which was vertically mounted on the voice board. These have been failing for years, and we think it would be fair to say that they will all fail in time. The cost of buying a full set of cloned modules is 250 Euro and to this must be added installation, recalibration and the almost inevitable repairs to the pitch bender and the front panel tact switches, a number of which are guaranteed to be faulty.. Whatever you pay for a 106, be prepared to spend another 400 Euro on it some time soon if you want it to work properly and to last.

In fairness to Roland, lots of products from lots of different companies tried the ceramic module approach, quite commonly switched mode power supplies for everything from Power Amplifiers to PC’s to medical equipment.

They almost all failed very early on, the technology was flawed, not the company.
As far as we know, no other synth manufacturer tried this technology, and Roland never did again.

The Korg Polysix is a lovely synth, it was concurrent with the Juno 6 and in terms of facilities they are fairly close.

There are some detail differences, but the programmability of the Korg gave it the edge over the Juno for the 6 months that it took Roland to bring out the Juno 60.
The major flaw of the Polysix is the battery that backs up the memory that stores the patches. In a forward looking piece of design, Korg used a Nickel Cadmium battery which could be recharged while the synth was powered up thus in theory meaning the battery would never need replacing. Alas after about 10 years, the battery started to break down and leak acid over the circuit board it was mounted on. The synth would keep working and remembering its patches for many years after, but the acid was quietly and insidiously leaking and eating through the nearby circuit board traces, eventually leading to weird problems with the Programmer section.

Again, this is not Korg’s fault, the underlying technology was the problem. Other synths that had NiCad batteries include the PPG Wave 2 and the Oscar. If you are buying a Polysix, check that the programmer buttons work and that the corresponding LED’s light up (faulty buttons are common due to oxidisation of the contacts but if a switch works and its LED lights up then that is good). The battery acid problem normally only affects the programmer section, so if that is working OK, then either you are extremely lucky or someone else in the past has fixed the problem.

All of the electronics in a vintage synth are repairable, the outer hardware is far more difficult and expensive to obtain, so our view is…

Buy the best that you can get, it is cheaper in the long run than finding that you bought a beatup ugly synth that you could spend a fortune on and still not be as good as your friend’s one.

Leave a Reply

Your email address will not be published. Required fields are marked *