[sdiy] A few Memorymoog questions

[Tim Parkhurst]

A few questions about the Memorymoog voice card:

1) I noticed that the card uses 4066 switches for CV routing, but
4016s for the audio path (VCO 1 and 2 waveform select). Any particular
reason for this? My guess is that 4066s perform a little better, and
their lower Ron is a benefit for CVs, while the 4016 is less expensive
and worked just fine for the audio path. Right? Wrong?

2) The selected waves from VCOs 1 and 2 go into the inverting pin of
the audio summing amp (U12A), while VCO 3's signal gets inverted (this
signal is used as audio and as a CV source for "voice mod") and then
sent to the NON-inverting input of the audio summing amp. This
configuration is an interesting one, in that it saves one op amp, and
lets the inverted and non-inverted signals to be mixed (without
canceling). Is there a noticeable (audible) difference between a
standard inverting summer and a difference summer?

Although i doubt any one of these items is responsible for the sound
of the Memory (some say even better/warmer/phatter than the Mini), but
they may offer some clues.

And finally: I'm watching "The Mummy" and I'm noticing that Rachel
Weisz is a very beautiful woman... sorry, got distracted there. Guess
I drifted OT.


Tim (Go Kimi / Team Ferrari!) Servo
-- 
"Imagination is more important than knowledge." - Albert Einstein