I need to switch to decaf :) Anyway I gave this some more thought, and had a chance to look over the schematics of the MOTM modules I have now. Square is useful as a clock (although I would say a 310 is a better choice than the 390 if you want a really stable 1U clock), but PWM isn't that useful. Saw without sync doesn't isn't that useful either, and you can easily get saw out of other 1U modules. Everyone seems to want sine. So this is my revised version of a micro dual VC LFO: ~~~ >I need "utilitarian", "cheap". OK :) >a) 3 pots, 6 jacks: (jacks cost less than pots, LED's draw current and make noise) 1) RATE 2) FM 3) LFO 2 6 jacks: 1) FM 2) LFO 2 3) SQ 1 4) TRI 2 5) SINE 1 6) 2 SINE At it's core are two tri LFO's. The second LFO (the one not used as a clock source) is deliberately very unstable. The module uses inexpensive sine shapers (like the overdriven OTA's in the 410), no tempcos, no exponential converters (although it might make sense to make RATE a log pot), no "gold plated" op-amps, and no LED -- 100% low-budget. LFO 2 and FM are reversing scaling attenuators. LFO 2 is normalled to a positive voltage. FM could also be normalled, to a small voltage, and used as a "fine" control. The second LFO can be controlled in two ways by using a switched jack. Without a plug, its input voltage is value of LFO 2 plus the voltage input to the first LFO (which is the sum of FM and RATE), such that LFO 2 serves as an offset, and FM and RATE serve as master controls for both LFO's. When a plug is inserted into the LFO 2 jack, the LFO 2 knob becomes an input attenuator. This way you can patch either output of the first LFO into LFO 2, or control each LFO independently. SINE 1 uses a switched jack -- unswitched, 2 SINE contains the sum of both sines (notice its name). While the SQ 1 and TRI 2 jacks could also use a summing feature, that might be confusing.
Message
390 uLFO: "Regis, this is my final answer."
2001-12-07 by mark@indole.net
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