MPC 2000 Classic: super strange volume issue.

So I copped a beat up MPC 2000 classic on craigslist for dirt, dirt cheap. (only 50 bucks).

This thing was in bad shape: buttons missing or damaged, scratched up case, the usual lines in the screen, wouldn't load a floppy, plus it smelled like a 2 year-old had been eating on it or it had been living in a dumpster.

So I gave the old girl some rehab...cleaned it up, replaced the floppy and various buttons, did the avery sticker mod on the pads to increase sensitivity...plus I pulled some older SCSI HDs and CD-ROM drives out of my junk closet that work perfectly with it.

I thought it was ready to go until I discovered a serious volume issue. The volume control still works, but the levels on the main outs are completely low. When using the headphone out, the volume is still low, but the volume control now pans the output from both ears to just one side.

Any ideas on how to fix? Do you guys think that getting the 8-out board would bypass this problem? Thanks.

check the board for a short, bad volume pot, or bad caps... maybe something needs to be replaced. I think that while the 8 outs bypasses the main outs and the main volume knob... it wouldn't be worth taking the chance buying a board that costs 3 times what you payed for the machine to likely find out it wont work properly in the end in case there is a problem on that part of the board too. The other problem is, when you are trimming or auditioning sounds..... I dont even think you can assign that to go to any of those outputs... only pads can be assigned to those outs, not system things.

Yeah it sounds like somewhere your loosing some power to the main outs, if it was the volume knob you wouldn't get the panning. Before you get elbow deep in your machines circuit boards make sure you've cleaned your main outs and that the audio cable is pushed in fully. If it still dosnt work then I'd start thinking about going in your machine and checking the cables and their connections. It definitely sounds like something going on between the main circuit board and the main outs because if there was low power before the main circuit board your machine would be acting funny.

I mean it sounds like you bought a machine on the brink of death, it makes sense that it would have some internal issues as well. But it sounds like worse case scenario you have to replace the main outboard.

I can also confirm that buying the 8 outs wouldn't help you, I'm on a classic with 8 outs and I still have to use the main outs when trimming or sampling.

But yeah, sounds like its loosing some of the voltage in either the connection or decayed wire. Im pretty sure because you say the headphone out does this as well which is actually a good thing because then you know it's isolated to that circuit board.

Thanks guys. I just downloaded the service manual. I'm going to check the cable to the audio AD/DA board and clean the ports with contact cleaner. It may be just a damaged ribbon cable.

A couple more questions in case this does nothing:

1. Which should I replace first. The AD/DA board or the whole motherboard. There's a used motherboard on Ebay for 30 bucks right now.

2. Is it possible to send the metronome to through the 8-outs?

Either way this isn't a much of a deal breaker for me. I don't plan on using the internal sampler that much. I have other rack-mount samplers including a Akai Z4 and Esi 4000 (which I also snatched both of those on craigslist for 50 bucks total).

The Z4 overcomes most of the 2000 classic's sampling limitations (file structure, transfer ability, memory), and I guess essentially turns the combo into a MPC 4000. The USB support is pretty amazing...you can just plug in a thumb drive with new samples and save the programs to the internal HD. Aksys works pretty well with Win7 also.

I just want this MPC to be fully functional (in case I need to sell it) and would also like to hear that familiar MPC metronome click.

this is likely NOT a power / digital issue as the main volume pot is just a basic analog stereo pot.

the fact that it pans when turned sounds exactly like a shorted connection.

i imagine if you replace the volume knob it would be totally fine. another option is to just bypass the volume knob...that's up to you.

i will say that getting at the volume pot is not as easy as you'd think.
edit: i have never replaced one on a classic - only xl. so can't really comment on how easy / hard it is to get at.

but your volume pot itself is most likely the culprit.

great snag - and good luck.

tapedeck wrote:this is likely NOT a power / digital issue as the main volume pot is just a basic analog stereo pot.

the fact that it pans when turned sounds exactly like a shorted connection.

i imagine if you replace the volume knob it would be totally fine. another option is to just bypass the volume knob...that's up to you.

i will say that getting at the volume pot is not as easy as you'd think.
edit: i have never replaced one on a classic - only xl. so can't really comment on how easy / hard it is to get at.

but your volume pot itself is most likely the culprit.

great snag - and good luck.

You were absolutely right...it was the volume pot. I ran out, bought some Deoxit, took the volume pot apart, drenched it in fluid (kinda) , and that fixed it. It's back to normal. Now all I need is a better screen.

Thanks guys.

i suggest doing the deoxit to the input gain knob too while you're at it if you haven't already.... great to hear you got it sorted out.

coolout1 wrote:You were absolutely right...it was the volume pot. I ran out, bought some Deoxit, took the volume pot apart, drenched it in fluid (kinda) , and that fixed it. It's back to normal. Now all I need is a better screen.

awesome - i meant to say you could try rehab but sounds like you figured it out on your own.

still keep in mind the rehab will only last so long - pots are cheap and getting it out is the hardest part - consider just replacing it next time it acts up.

props.

My b on the bad advice then, I've dealt with some power issues in other electronics that lead to smearing/panning issues. Glad you didn't have to replace entire circuit boards for a fix. I also concurr a temp fix is just that, temp. Peace