All posts tagged synth

Oberheim Four Voice (FVS-1) Restoration – Part 8: The SEMs


In the spirit of saving the easy stuff for last (…or so I thought), I tackled the restorations of the four Synthesizer Expander Module (SEM) units.  These were more work than I had anticipated, but then again I opted to completely disassemble them, clean, re-cap, and repair any issues along the way. Fig. 1 – […]

Oberheim Four Voice (FVS-1) Restoration – Part 7: The Programmer


In 1976, the Four Voice began being offered with a programmer module.  Oberheim’s  patch storage implementation was a bit different from that of the microprocessor-controlled polyphonic synths to follow (Prophet-5, OBX, etc…) in that it was capable of  multi-timbral storage/recall of sounds.  In other words, each SEM could be setup differently using the programmer’s controls […]

Oberheim Four Voice (FVS-1) Restoration – Part 6: Cosmetology


I’ve been making some progress on this restoration, and thought I’d lump together a bunch of the more superficial, cosmetic-oriented work in this post. While I’ve had the synth chassis separated from its roadcase, I felt that it would be a good time to freshen things up a bit.  The I/O and power supply panels […]

Oberheim Four Voice (FVS-1) Restoration – Part 5: Keyboard Rehab


Forging on ahead, I felt it was time to give this keyboard some new life.  The bushings were pretty much shot, and several were starting to crumble away – yielding the all too familiar snaggletooth keys and loud metal-on-metal action:     Getting the Four Voice’s keyboard assembly out involves excavating the synth from its […]

Yamaha CS-40m


These are some photos of my old CS-40m.  I loved the filters and ring modulation in this synth, and it was built like a tank!  The design lacks some niceties like FM and sync between VCOs, but it was still a joy to play.   This synth also interfaced well with my modular.  Here it is with […]

Oberheim Four Voice (FVS-1) Restoration – Part 4: Hearing Voices


Now onto the fun stuff…  I’ve been seriously digging this thing even as it limps along with two-voice polyphony, but its time to hear a happy quartet of SEMs! SEMs 3 and 4 were not firing from the keyboard, and the continuous assignment mode would only step between SEMs 1 and 2.  Between all of […]

Oberheim Four Voice (FVS-1) Restoration – Part 2: Modification Removal


Well, where to begin… I thought I’d start by tracing out and removing the modifications.  Overall, the mods looked to be in a questionable state, and I felt it would help in troubleshooting the primary issues if I could rule-out the modifications as a contributing factor. The “Mediamix Triangle Mod” board was held in place […]

Oberheim Four Voice (FVS-1) Restoration – Part 1: Introduction


I’ve been fascinated by this synth most of my life, and I finally got a chance to lay hands on this one in June 2011. In or around 1975, Oberheim released the four voice polyphonic synthesizer (dubbed the FVS-1), which was basically comprised of four Synthesizer Expander Modules (SEMs; keyboardless, monophonic synths that were originally […]

Fun with Breadboards!


I snagged an old Heathkit “Electronic Design Experimenter” off Ebay for around US $23, when all was said and done. Didn’t think I’d be excited about a breadboard – but this thing’s neat!  In addition to the breadboard, it contains a bi-polar power supply (each rail independently variable up to 15V), pads to distribute 15 […]

1974 Minimoog Model D Refinish


I acquired a 1974 Minimoog Model D that plays and sounds absolutely amazing, but this thing was really rough in the looks department.  I had to get into it to repair its volume pot (it had been replaced with an 16mm center-detent pot of the wrong value) and do a couple other minor things, and […]

Pro-One Easter Eggs


I remember reading somewhere about the hidden Easter eggs etched and screened on the PCB of the Sequential Circuits Pro-One synth.  These are only visible when the board is completely removed from the front panel. Here are some photos I snapped while mine was in pieces for servicing…   Chenrizig:   I believe this is […]