Post your questions, opinions and reviews of the MPC1000. This forum is for discussion of the OFFICIAL Akai OS (2.1). If you wish to discuss the JJ OS, please use the dedicated JJ OS forum
By Paradigm X Mon Dec 20, 2021 10:11 am
Been looking into improving the audio quality of the 1000s, and can see some potential upgrades. Ive also seen similar posts in here on the 500.

The output board uses a load of dirt cheap (probably bare minimum sizes) electrolytic capacitors and cheap as chips mylar polys. I was thinking of replacing these with high quality low esr caps (probably make biploar in the audio path to reduce distortion) and WIMA polyboxes for the mylars. And upgrading the psu filtering caps with similar HQ caps. I like the panasonic FR/FM models and ive got a ton on hand. Its also likely/possible that increasing the size of the audio caps/psu reservoir caps will help, possibly bypassing the audio ones with a small poly prop or similar.

Ive recapped a number of old desks/fx units/synths and the difference is usually very noticeable. IN a good way. but the mpc isnt as old as most of these so not sure if the difference will be as big. that said this was defnitely built to a budget so i hope that there will be some improvement.

Just wondering if anyone else had tried this first, and/or had any tips/findings? Im thinking i might try to do just channels 3/4 first so i can compare to 1/2. But quietly optimistic it should be an improvemet.

In an ideal world id also experiment with replacing the opamps, but they are smd and a pita to desolder and this is an order of magnitude more difficult (high speed/quality opamps can need all sorts of additionally filtering/decoupling etc which is beyond my skills at this point). theyre already 5532s which are much better than the cheapest types so will leave them be.

Ive fully searched and spent an evening on this website going through all mentions of 'capacitor', 'opamp' etc and theres some interesting topics, especially the 500 post relating to a similar upgrade, but none specific to the 1000.

If i go ahead ill share photos/results. As i said im quietly optimistic it shoudl improve things, but a bit reluctant to lose the centre of my studio. should be doable in a day tho.

cheers
By Paradigm X Sun Dec 26, 2021 2:30 pm
Hey

Yeah, been looking into it. Couple of things putting me off;

The audio board is a complete PITA to get to; its beneath the main board, so id have to take the entire thing apart and remove all the cables. Not in itself a big problem, but obvioulsy more can potentially go wrong compared to just leaving it alone.

The PSU is an off the shelf one, not made by Akai (why its not in the service manual). An earlier version is known for causing problems in other audio gear, specifically due to to the caps, so may well be worth replacing with high quality caps.

My unit works perfectly, and doesnt actually sound bad; no hiss etc. Its just got this 'cheap' grimey smeary sound to it compared to say the s2000 i also own. Im hoping the cheap caps will improve it but no guarantees so again a bit reluctant to pull it all apart.

The main thing is ive had some time off work and had so much fun just playing with the akai again its putting me off pulling it apart. ILl have to see.

FInally, the worldwide electronics drought seems to be hitting caps too. some of the sizes used are hard/impossible to buy at the moment. For example the feedback caps in the outputs is a very specific 18pF capacitor. This is a non standard size which makes me wonder why Akai chose it - 22pF is a bog standard size and is used on the inputs (although there are 8 opamps used per channel and they all use different sizes which is odd). I cant personally see why it would make any difference TBH (theyre all just used to stop very high frequency osciallation of the opamps and theyre all well above hearing range), so i cant see any problem with replacing them, but im starting to have doubts. There must be a reason akai used them, if it really was built as cheaply as possible i assume theyd have just used standard sizes for all of them, so im wondering why they didnt. They know better than I do... and makes me think i should not change them.

I was hoping someone else might have done it first or had some thoughts.

So at the moment its kind of stalled/on hold. I still beleive that replacing the cheap electros and mylar polys with high quality like for like will only improve things, but maybe not a huge amount, and im debating whether its worth it or not tbph. I have recapped a few old units and noticed a big improvement but they were much older units. That said the older stuff used decent quality parts ... hmm.

If i do anything i will post here. Still debating.

cheers.