This weekend I’ll be doing minor repairs to the Roland JX-3P and Realistic/Moog MG-1 synthesizers, as well as some modifications to the Marantz PMD-221 cassette deck and Intellijel Eurorack 2HP passive Mult module.
- Record example sound with chorus off, chorus on. Check volume pot and output level switch. DONE
- Replace volume pot, output level switch as necessary. VOL POT DONE, OUTPUT LVL SWITCH OK
- Replace MN3009 BBD x2 DONE
- Close up and test. Re-record example sound with chorus off, chorus on. DONE. FAIL. NEW ARTICLE WILL BE POSTED SHORTLY.
Realistic Moog MG-1
- Record example playing of all keys – explore defective notes. Explore delay from poly to mono osc.
- Replace octave divider(s) as necessary. BUILT TWO OCTAVE DIVIDER REPLACEMENT BOARDS USING BOB GRIEB’S PCBs
- Confirm defective notes are repaired.
- Replace CV extraction capacitor per Bob Grieb’s recommended keyboard delay mod.
- Test keyboard delay.
Marantz PMD-221 Pitch Control Mod
- Test deck in delay loop. DONE
- Install “pitch control while recording” mod DONE
Modify Intellijel 2hp passive Mult module
I took some pictures while I worked. It will get its own article later this weekend.
Tested. An S-trigger is generated when the voltage goes above approximately +0.55V. All things said, this was a very worthwhile mini-project. New article with details will follow shortly.
Next priority jobs:
- Sequential Multi-Trak – Tauntek Update IN PROGRESS
(This job would have been my top priority this weekend, but Mouser decided to not ship my Schottky diodes for no good reason)
- Korg EX-800 Sale Preparations: Moog Slayer / FM / Side Panels
- Yamaha CS-40M Repairs
- Display Replacement: KorgWavestation A/D (and maybe get some rack ears)
- Display Replacement: Yamaha TG77
I will post further updates. Use the tags if you are trying to follow something specific.