not to stir up trouble, but...

[torinkrell]

The biggest difference between the 1978 Minimoog D I used to have and the 1973 Minimoog D I have now was the way the oscillators beat against each other. The 1978 Mini produced bright sharp irregular ripping like overtones (as the osc locked in and out of phase) whenever the oscillators were set just slightly apart pitch wise while my 1973 Mini D just gives me that rich "phat" sound I am looking for. It was to the point where If I wanted to slightly detune 2 oscillators for richness I would prefer my Pro One instead of the 1978 Mini D. My 1973 Mini D has no such problem and sounds better and richer than the Pro One when I slightly detune the oscillators against each other the same way. Unfortunately I haven't opened either Mini up to see which version of the oscillators they have although neither had the 9 oscillator tuning holes on the back (I am aware though that, according to some techs, the oscillators can be upgraded without putting on the new back panel with the 9 tuning holes). The 1978 had very stabile tuning and the 1973 takes just slightly longer to stabilize but then is just as steady. Can anyone explain what was going on with my 1978 Mini D?

[MC]

That irregular "ripping" sound is the oscillators attempting to "lock". The power supply has just enough dirt on the rails that it knocks them out of lock. Back then Moog built an "improved" power supply for the minimoog but the oscillator locked so they left it as is.

Your '78 probably has cleaner power rails than most others, so you need to make them dirtier. Try throwing some sand on it (kidding). Maybe another scavenged power supply would "cure" it.

[torinkrell]

The 1978 Mini D was the 2nd Mini I owned (the first was a 1975 Mini). I sold it around 2000 to Tom Brislin as he needed a Mini D for his keyboard duties for Yes. A few years later I acquired my 3rd Mini, my 1973 Mini D, which is the best sounding of the three and still pleases me more and more each day!