General Synth Maintenance Thread

The crown jewel of my synth collection is a Poly Evolver. I drove 12 hours round trip to get one I saw on Craigslist. It’s my favourite synth and it’s in great shape with the new knobs and everything.

What maintenance is required for a synth like this? It’s not ancient or anything, but I feel worried sometimes wondering if a day will come where it’s not operational anymore.

It just sits on my desk, covered up with a cover. Sometimes I’ll go stretches of time without turning it on. Is there any kind of general maintaining that needs to happen with synths of a certain age? Am I screwed if something ever goes bad? It seems like some gear is much more easily serviced than others. I know sequential is known for fantastic service…

I’m still relatively new in this world and as passionate as I am, I’ve only been in this hobby for like 7 years. I don’t have long term experience with gear. Would appreciate any general tips!

1 Like

Firstly that is one hell of a good synth you have there so I understand your concerns!

I have the Poly Evolver Rack hooked up to my Mono Evolver Keys both of which have not let me down and I must have bought them 15 years ago now with some prolonged periods of non use. I dont cover them when not in use but I definitely think that is a good idea for your Poly as it will keep the circuit boards a little cleaner over the years i imagine.

If something does go wrong I think you could still reach out to Sequential for advice and it’s unlikely there would be nothing that could be done. @Scot_Solida will have a better knowledge of maintaining older synths so he might be able to chip in.

I would just get on and enjoy this amazing synth without worrying too much!

1 Like

I wouldn’t worry too much.

Sequential are a thriving business and should be able to help with most issues that may arise. Failing that, there’s always someone who can fix a synth out there.

I’ve owned gear more than twice the age of your poly that works flawlessly and gear that has crapped out after less than a year. It’s always a bit of a lottery, this hobby, but buying from quality brands like sequential should ensure a level of confidence in quality.

Over time you’ll probably have to replace the odd internal battery and it won’t hurt to get it looked at/serviced by a professional every ten years or so (because capacitors don’t last forever), but there’s no reason your synth shouldn’t outlast you.

I bought a Polivoks Pro last year. Handbuilt by people in a country I can no longer send it to and full of largely unobtainable NOS Soviet components. Still managed to find someone who can fix the dodgy filter envelope on it, albeit with a loooooooong waiting list.


A good general tip I’d give for anyone with aging synths in an uncertain market is to identify any IC’s it uses and buy some spares. A lot of them are fairly generic or get superceded by compatible alternatives but from time to time they can be the thing that makes repairs the hardest (or most expensive) down the line due to unavailability, or changes in architecture etc. Buying them when they’re commonly available will be cheap, and even if you don’t end up using them they’ll probably be valuable to someone at a later date.

Otherwise keep it away from moisture/humidity and don’t spill your wine on it.


Super helpful feedback y’all, thank you for these posts! Reassuring for all my gear moving forward.

Btw, what are ICs? Is there a general place to get them/look up which ones I need for a synth?

Integrated circuits. In the context of this discussion they’re the chips that make and process sounds and control various aspects of your synth. Typically black and rectangular with a bunch of bare metal “legs” sticking out the sides. They come in all different sizes and configurations and often have identifying information printed on them. You could probably find a list of the ones used in the poly evolver online or by contacting sequential.
To add to what natehorn said, if there are any other unique or otherwise unusual parts it wouldn’t hurt to keep an eye out for spares of those too (unusual encoders, output relays, etc). Electrolytic capacitors go bad over time but those are usually better purchased when needed as they don’t like to just sit, you can prolong their lives by using them.
Amazing synth by the way. I have the desktop version and it’s a contender for my all time favorite synth.

1 Like

Thank you for the explanation! The desktop was the first one I tried and I was blown away by it.

I got obsessed with tracking down a mono and poly and finally found both. They’re such special machines and the sequencers are just spellbinding!

It would be amazing if there were reissues one day!

1 Like

Great choice of board!

Afaik the main ‘not off the shelf’ IC’s are the CEM3396 (if I remember correctly DSI use a different part number but it’s the same chip) in an SOIC format that they sourced from OnChip. Sequential may still hold a stock of these. I think the processors (2 off) are Microchip PIC’s. They prob shouldn’t be hard to source if required? Again, Sequential may hold these too?

I sent a board from my PEK to them a few years ago when I snapped an encoder shaft and they repaired it fir a reasonable fee. I was too busy at the time to do the repair myself. Although I’ve not done a deep dive into mine the display is just a 2 row super twist so shouldn’t be hard to get a replacement if required. I wouldn’t worry too much about caps and unless you know you’ve got a failed one I really wouldn’t go to the bother and expense of a re-cap. They can last donkeys years and although their tolerance might drift they’ll still work perfectly well in most situations. Yep, they do fail on occasion but they can also last a lot longer than their ‘expected’ lifespan, more so with modern components. I’ve said it before but I’ve got vintage synths and keyboards that are still working happily with 40+ year old Electrolytic’s. The old adage “If it ain’t broke don’t fix it” applies here.


The Poly Evolver is super easy. Just make sure to change the oil every 4500km

I am no expert… I’ve just had a lot of old, broken synths! :sob:.

In the case of the PE, that would be something I’d have to send to Sequential if anything outside of mechanical components were to fail. It’s all SMT, and I have almost no experience repairing such things. Old through-hole boards are easier (depending in the boards), but SMT is a job for someone else.

Even if it weren’t SMT, it would probably go to a tech due to its complexity. Somethings are an internal nightmare and beyond my abilities and/or patience. For example, I don’t like to open up my old Prophet-5, so that one goes to my tech when it needs work.