MOTM-190 features
2002-07-14 by Paul Schreiber
The 2 VCAs are totally independent (they are not even connected to each other). The top-most knob is a little freaky (and hard to label), because it has 2 *different* functions. In RM mode: The pot is like a "Dry/Wet" blend on a '410. Fully CCW, the output is the input (a wire!). At 12'oclock, it's AM, and at full CW, it's RM. In VCA mode: The pot acts like "Initial Gain" on a '110 BUT, the circuit uses a 'trick' so that the pot setting PLUS the incoming CV is normalized to *unity* gain. Example with ADSR input (0 to +5V): a) Fully CCW, the output = the input (a wire again!) b) at 12 o'clock, the gain goes from 0.5 to 1.0 Now this is a little strange, as it won't gate the audio off/on (like it would if the gain was say 0 to 0.5). c) fully CW, the gain goes from 0 to 1 (I would call this 'normal VCA operation') It was dones this way to save 1 pot position, and to offer the AM/RM blending feature. Rather than the '110 that has 1 VCA and 1 RM that makes a so-so VCA, the '190 has 2 good VCAs AND a good RM. This one funky control is hard to "get your head around" until you use it. In VCA mode, you just turn the pot all the way around and it behaves as you expect. Same with RM. Most times, the pot will sit over fully CCW. But in RM mode, it does sound uniquely different than other RMs you may have heard. Paul S.