For a non serviced unit and bad cosmetics I wouldn’t value it over 2k. I’ve seen a few in bad state for 1k which is still pretty generous. For a serviced unit that’s well preserved it would be fair for 3,5-4K and if it has midi interface and a modern PSU it’s around 4-4,5k.

Oberheim Matrix 1000 new PSU now available, for those who have humming problems.

https://synthronics.de/matrix-1000-psu- ... wAR2rejZCW Ue2yDZC8UJK0Rfq2D5v8s86wGT9xaIk-5WhXL7bhrBbGKZ6NHA

New PSU for JP-4 available now: https://synthronics.de/roland-jupiter-4-new-psu/ Less heat. Efficiency around 78% (incl. linear regulators) (efficiency of original PSU is 55%). No audible noise. Precise Over Current Module that monitors possible fault conditions. Less weight (320g incl. metal cover ...

Polysix PSU replacement now available, much more efficient and less heat: https://synthronics.de/korg-polysix-psu-replacement/

Roland Jupiter-8 replacement PSU is ready: https://synthronics.de/roland-jupiter-8-new-psu/?fbclid=IwAR1apRcq-64s66E3edaD9695AoyU5g_iVKpZuW1_UutQqMmNpEmB7oTcIZ0 No overheat Efficiency around 75% = less heat inside the synthesizer Noise free Precise Over Voltage and Over Current Module that monitors ...

Prophet VS PSU now available! https://synthronics.de/sci-sequential-c ... er-supply/

Just a heads up, Andrej from Synthronics is releasing a bunch of custom replacement PSUs for classic vintage synthesizers and I have to say I'm impressed. Just installed my replacement Juno-6 PSU and on top of being smaller and lighter than the original it seems to have better groundings and isolati...

Oh yeah I know, nothing special about those, just pointing out for future reference as source, I couldn’t find them locally.

For reference, this is where I got my original NOS 2SC2878A pair:

https://www.soundtoparts.com/en/compone ... c2878.html

Nope. Mine sounds the same, normal as usual... Yes, you get a very distinctive distortion in some settings when these degrade. You can hear it in most of Synthmania’s Juno-60 videos and others. I wonder how many confuse this issue with faults on the MN3009 BDDs. I’ve seen this as a suggestion in mo...

Ok I fixed this. I can confirm it was the muting transistors that were degraded, TR7 and TR8. You have to replace them with the exact part numbers 2SC2878A, no equivalents or others will do (I had put equivalents with the same specs when I began investigating the issue. Both the originals and replac...

Any news?? It´d be good to know if at least one worked :thumbright: Sorry, been out of the loop for a week. Logarithmic slider did mostly fix the issue, though still present on extremes and I'm not really that fond of the resulting curve. Increasing resistance at R36 seems the most obvious better s...

It´s intriguing because the positive supply is what tames down the control voltage, like take -10V, add +5V and the sum is -5V... Have you traced the entire control path? Another curious thing is the 10k law faking resistor for vr3 seems an afterthought, as it has no ref. number and there´s no sign...

ha! where is r165?? Are you going to decrease the resistance of r165 from 15k to say 10k? Well it seems the first revision of this board is made to cope with the linear signal and designed not to have R165 present at all (I’ve seen pictures of the other side too). It’s the same in every other way a...

Take a look at this very early board revision and tell me if you see something weird about the VCA scaling resistors ;) http://www.spheremusic.com/userimages/Img15647-4.jpg I think I might be fixing this today, though your method of turning the signal into logarithmic should also work (cause that's ...