Analog synthesizer repair, parts, sales, and innovation. I buy broken synthesizers!
We repair another handful of problems with the vintage Oberheim Four Voice Synthesizer (FVS).
00:36 Dirty & misadjusted key contacts repair
04:37 Scratchy Pots repair
07:55 SEM4 no pulse waveform repair
10:59 Some poorly played sounds of the Four Voice
We repair a handful of problems with the vintage Oberheim Four Voice Synthesizer (FVS).
00:14 Demo of some of the problems
01:27 SEM3 stuck on fix
03:17 More programmer problems
05:30 Why shotgun repairs are not always a good thing
07:30 Memory bank select repair
10:32 SEM1 & 2 Memory Mode repair
14:42 To be continued…
I’m going to be doing some repairs on this Oberheim Four Voice synthesizer and I thought I’d make a repair video on it. But first I want to provide some better context for the repair work that’s to come. So in this video we’ll look at the inside of the Four Voice, see the different modules that make it up and discuss how they work together to make an amazing synthesizer.
A customer brought in his ARP 2600 that started smoking while he was using it. I show you how I quickly locate the offending component and what I’m going to do to help his synthesizer kick its dirty smoking habit.
New synths seem designed to be disposable, or repairable by replacing a whole board, which often costs more than the synth is worth. Today we do board level troubleshooting and repair on this Korg MS2000R that had no output and gave a “MPUtoDSP check error”.
00:00 Intro & where I’ve been the last few months
02:48 The problem & troubleshooting plan and setup
06:08 Oscilloscope probing
12:27 Removing the old DSP chip
14:33 Soldering the new DSP chip
16:15 Test and head off for a cold drink
USPS is delivering again to Australia, so orders can once again be shipped down under.
Recently got a question from someone unable to save patches on his OB-Xa. “Where is the memory protect switch located?”. On the OB-X and OB-Xa, the memory protect switch is located on the main processor board inside the case. To access the switch, you will need to unscrew two screws on the left and right of the synthesizer to lift the front panel and access the board. The switch is located as indicated in the pictures below. On the OB-8, someone finally got a clue and moved the switch to the back panel where it can be accessed without opening the synthesizer.
Today we have a look around inside a of couple Oberheim OB-X synthesizers. I give a techincal overview of what goes on inside the synthesizer, we look at some of the differences between the earlier and later OB-X, and I show you the weak links that you’d want to address or at least keep an eye out for when repairing or restoring one of these synthesizers.
In this video we troubleshoot and repair a dead Juno 106, that powers on but either the LEDs flicker or the display reads “8” and the synth is non-operational. The theory I touch on and process I use can easily be applied to any other microprocessor based system that isn’t booting.
Some people claim the Oberheim OB-SX is a smaller, preset version of the OB-X. But is that really true? In this video we take a look the voice cards of the OB-X, OB-SX, and OB-Xa and explore their similarities and differences.
