Micromoog basket case

[Voltor07]

The Micro is working great, and has a CP-251 and a Electro-Harmonix 8 Step Program now. Check out that 8 Step, it's a very cool CV sequencer and a bargain too.

Question: where do you take the trigger or gate signal from ? The EHX doesn't generate any (AFAIK) ?

There's a simple mod described online that shows how you can get gate out on the EHX.

[MC]

Here's a question I've been meaning to ask. My son says his Micromoog gets out of tune when the humidity in his apartment gets too high (like 65% rh) although the temperature is 78 F. Anyone heard that one before?

Could be contaminants on the circuit board. As humidity rises, so does its conductivity (it slowly becomes a low impedance). Hopefully it's on the surface of the board.

[thealien666]

Thanks Voltor, I didn't know about the mod.

[armillary]

Thanks MC, your answer makes complete sense. The main board has lots of surface contamination on the top. I have cleaned up small areas with CRC Electronic Cleaner on a q-tip, but there are many areas left.

On the 8 Step, my son uses it as an input to the mixer section of the CP-251. I replaced the 3/16" mod jack on the Micromoog with an equivalent 1/4" Switchcraft jack, then made a patch cable with a male mono plug on one end and a male stereo plug on the other. The tip of the mono plug is wired to the ring of the stereo plug, as per the diagram on page 76 of the Micromoog Operation Manual. This lets the output of the CP-251 control the mod on the Micromoog.

Thanks for the link to the gate trigger mod for the 8 Step. I assume by gate trigger, it's a voltage trigger, as opposed to a switch trigger. There's a v-trig to s-trig converter on page 69 of the Operation Manual. Lots of easy projects in those few pages.

[Voltor07]

Yeah, it's a V-trig, like most modern analog gear. And Alien, you're welcome. The mod is pictured here http://www.muffwiggler.com/forum/viewto ... c&start=40

[Kevin Lightner]

I'm not sure if you're aware, but the Micromoog (and Multimoog) use "heated chip" technology.
There's a trimmer inside that's factory adjusted so the internal temperature of chip is set higher than any temperatures one is likely to see. 131F (55C) to be exact.

If that trimmer is set incorrectly, the pitch of the synth can vary with changes in room temperature.