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.
It’s been a busy week behind the scenes at Studio Nebula. Not a lot of creative stuff going on at the moment, but I’ve taken the time to give much-needed TLC to some vintage gear.
The Maxim MDS-500 is not ready for action yet. Honestly, I’m sure it will ever be. It just doesn’t sound very good. I haven’t given up all hope though – I have a couple of suspicions about some things that might not be working as they’re supposed to, but it’s tricky to troubleshoot with no frame of reference. This is the only one of these I have ever seen, I’m not completely sure what it’s supposed to sound like, and there are no schematics or service documents. (If somebody out there has schematics, please let me know!)
Problems I’m having with this MDS-500:
- The “noise” doesn’t seem to be as loud as it should be. (Try to find the noise source, disconnect it from each voice 1 at a time – perhaps one voice is loading it down for some reason. Otherwise, perhaps the noise has an output buffer that is not up to snuff)
- Most of the front panel pots are intermittent, filthy.
- Despite trying lots of settings I haven’t really heard anything that sounds like it’s filtered by an SSM2044 – yet there is an SSM2044 filter per voice!
I’m just not sure yet whether this device needs mods, repairs, or if it’s just crap.
A photographic exploration
…of my new Sequential Multi-Trak. Planned work:
- Replace the battery
- Install the new Tauntek/Bob Grieb firmware
- Perform battery drain / current draw mod (if necessary)
- Replace buttons which have yellowed over time
- Replace foam in the flight case