Recently a friend has acquired a Multimoog via eBay. The instrument was in a pitiful condition, more mechanically than electrically (lucky!). We have pretty much refurbished the Multimoog now, but we are left with one question. We did all the tuning according to the Technical Service Manual and the instrument is pretty stable, only the Filter makes some problems (at least we think it does...). When the Filter is in NORM or FULL mode, and the Cutoff knob is turned Counter Clockwise beyond the 10 o'clock position, the volume of the sound also decreases much more than one would expect - in fact we have compared the filter with the one on my Prophet 600. The question is whether the behaviour of the Multimoog filter is ok, which means no sound at all below the 9 o'clock position, or whether there is something wrong with the filter components ?
Oh..., we did one modification, it is described here: http://www.physicsenterprises.andrews.e ... cfmod.html
which is paralleling the C506 with a 100uF Capacitor ot get actually MORE bass out of the Filter, not less....
Any help is appreciated.
Multimoog Filter Problem
Where are the Tri, Pots ?
Hi, thanks for the input. In the technical manual 4.5.3 and 4.5.4 two trim pots inside the synth are described (R514 and R381). However, there is no indication where exactly on the mainboard they are located. My Multimoog has Serial Number 1450, so it should have the pots - right ?MC wrote:I designed that mod. Shouldn't cause the problem you're seeing.
Sounds like the calibration isn't right on the filter. It should have plenty of range in its sweep of the cutoff knob. Try recalibrating the range trimpot again.
When I glimpse between the cover and the mainboard I can see two trim pots, one above the "mod source" Pot and one above the "Volume" Pot - are those the right ones ?
The manual also mentiones PL3/6 where one should monitor 5.00V - where is that ?
I would be very greatful if someone could answer the questions.
Mat