Roland SH2000 wacky tuning

dafydd · Post by **dafydd** » Mon Jun 23, 2008 5:11 pm

Hi folks

Last night this SH2000 I have on loan went a little crazy tuning-wise. It was doing fine, then I came back to it an hour later and the overall pitch had shifted dramatically, and the internal tuning was way off. Currently the intonation across the length of the keyboard is compressed by about a whole tone, and this is after some messing - it was almost a perfect 4th when I started.

I've found 5 pitch controls - there are 2 on the outside which affect the overall pitch. On the inside there's another overall control trimpot marked "VCO TUNING". There are also 2 trimpots marked "LOW TUNING" and "HIGH TUNING", which seem to affect the stretch of the scale as you move away from the middle of the keyboard. Currently I've got both stretched as much as possible. The upper half is _almost_ okay, but the low end is really compressed - you have to play a -9 to get an octave.

Has anybody come across this before? Any suggestions? Is there anything I'm missing?

Thanks for any help.

cheers
dafydd

Post by **Maschinengeist** » Mon Jun 23, 2008 11:46 pm

http://technopolitan.se/manuals/Roland/ ... Manual.zip

Please find here the service manual and the tuning procedure is on page 23.

Hope that helps

dafydd · Post by **dafydd** » Tue Jun 24, 2008 2:26 am

Wow. Thanks! This is going to be a big help.

Wish me luck.

cheers
dafydd

dafydd · Post by **dafydd** » Tue Jun 24, 2008 3:14 am

Damn. It's not working. I think there are some old, old components here that are going to need replacing. Where to begin?

Thanks for your help though. This manual is brilliant!

Cybananna · Post by **Cybananna** » Tue Jun 24, 2008 3:40 am

fyi, my sh1000 (somewhat similar and from the same time) has the same problem, i think. my guess is that it is power supply related. I have tried the cal procedure several times with no luck. just haven't had time to replace the caps. in a synth that old, it could be any number of things though...

Cybananna · Post by **Cybananna** » Tue Jun 24, 2008 3:41 am

fyi, my sh1000 (somewhat similar and from the same time) has the same problem, i think. my guess is that it is power supply related. I have tried the cal procedure several times with no luck. just haven't had time to replace the caps. in a synth that old, it could be any number of things though...

dafydd · Post by **dafydd** » Tue Jun 24, 2008 3:45 am

Well, it turns out a friend of mine knows a whole bunch about these things. Whaddya know. We're going to dig up the problem. When we figure it out, I'll post it. thanks for the tip - I'll start with the power supply.