June 16, 2010
I recently repaired a 227. It has several problems: A dead channel, reverb wasn't working, I forget. It seemed like a quick turn around repair, until I sent it home and got the dreaded, "this thing's broken again!" phone call. Only now, it was completely shutting off the main output whenever it got hot. So, as long as I kept it on my bench, with air flowing around it, no problem showed up. After 5 minutes inside the boat, the main output went dead. This problem drove me nuts for a while, and in the end it was a Vactrol! Since the main output buss is quad, the panel volume control is actually a 4 channel Vactrol VCA. I guess diodes sometimes go open with heat if they're old enough. In this case the diode was a vintage Vactrol.
February 1, 2010
January 9, 2010
January 8, 2010
I repaired a MArF a few years back, but nothing was like the undertaking of getting the 248-3206 from the Buchla garage sale working. I only know of a couple of these in existence and I don't know that any of them work. Someone bought the panels with only the motherboards attached. I have had them in my possession for more than 2 years. I had to design, assemble and troubleshoot the input board and 3 output boards for this beast. Each board is 14" x 6" or so, no small task. Today it worked for the first time.
Pictured is the working MArF as a reference. and the 2 panels from the double size expanded unit. A 3206 is a normal 1602 unit with an additional 4 space panel added to it. The expander adds another 16 stages of sliders and memory as well as 4 more output channels. The 6 total output channels can address the 32 steps in any way. This thing could be a 200 system's only source of modulation generators. LFOs, Envelopes, Sequencers, Quantizers, Voltage Processors are all possible. More infos to come.
Much more info to follow.