I just ordered this module , now what the hell are I going to do . Any of you readers for any amount of time knows that Norm Fay is not f to be regarded in the least bit lightly.. those of us who make serious noise or serious money doing this must pause. .. C'mon guys I work for the feds and have been detached hence no time.to volunteer. Help G Wong "J. Larry Hendry" wrote: > > Norman, > This is some really great stuff. You got me thinking WHY? And then you > answered. A very thoughtful mail no doubt. > The CV input of the 700 already feeds a comparator. The + side fed by the > switch pot is already scaled for + / - 5 volts by the resistors at the ends > of the pot. So, I cannot see any reason that you could not use a voltage > input here instead of the switch pot. My lack of expertise leaves me with > some questions though. > > Standard Stooge Disclaimer - I have not tried this. Do not do this. This > is for the purpose of discussion. > > 1 - would you need to buffer the input - I don't see why > 2 - would you need a filter on the CV input like Paul has > put on the actual CV input (R9 and C7). > > But, in general, it seems like you should be able to interrupt the > connection between VR1 and the LM311 pin 2. Put your CV input jack here and > set VR1 wiper to the switch on the new jack to that when nothing is plugged > into the new CV jack, VR1 functions as normal. > > If you wanted to still have the biasing ability of VR1, it would seem to me > you would need to add a summing stage to add the voltages of the pot and > this new CV input prior to going to the comparator. But, that seems > unnecessary and beyond what you were trying to accomplish. > > Very interesting. I like your thoughts on this. > > Larry > > P.S. without modification, the 822 voltage switch will only output 3.917 > volts max. > > ----- Original Message ----- > From: norman fay <NFAY@...> > To: <motm@yahoogroups.com> > Sent: Friday, February 09, 2001 6:58 AM > Subject: [motm] suggested mod for motm700 (longish) > > This is a module I haven't got yet, though I do mean to get one, as I > can imagine several uses for it. At the same time, I've been looking at > the serge "com" (dual comparator) and comparing them feature-wise. > Though both modules are based around a voltage-controlled switching > function, both modules produce different results. The MOTM switcher, > I'm sure you all know about. The serge comparator, OTOH, has two inputs > marked + and -, a threshold knob and a single output per channel. what > they do is this: one runs a different voltage/signal into each channel. > If the + signal is greater than the - signal, the output goes high (+5v) > if not, it goes low (0v) Using the threshold control, one can either > generate square waves/pulses from a single input, or raise or lower the > + signal (I think....). I've been racking my brains trying to come up > with a way for the motm700 to do this. The voltage bit is easy - set > the mode to voltage, and feed it with +5v into one input and 0v into the > other (you could use l. hendry's octave switcher to generate the 5v) > however, the dual cv inputs are a problem....the only way to do it would > be to add another cv input to each half of the module, which would > interact with the "switch" knob. In this case then, if the > signal/voltage at "cv in" is greater than that at our new input, the > module would switch one way, if it were lower, it would switch the other > way. In this case, the "switch" knob could add or subtract from the > voltage present at the new input, thus acting as a threshold control. > Now, I'm absolutely *sure* that there are folks on this list who could > perform this mod! > Now, the question you'll be asking is this: why? Well, here's a few > possibilities: > > 1/ from the MOTM700 page at www.synthtech.com: > "audio demo - chopped up audio switching between 2 waveforms with the cv > as a 250 hz triangle. you can hear the timbre shift as we manually move > the SWITCH control" > with this extra cv in, you could control this timbre shift with an > envelope or an lfo. > > 2/ with a sequencer - clock the sequencer with a narrow pulse wave lfo > signal, also run pulse wave into MOTM lag processor (fastest attack, > slower decay) run lag proc out into CV in of MOTM700, run cv source (eg > lfo or second row of sequencer knobs) into new switch CV input. 5v into > one i/o socket, 0v into other - result = VC gate time! > > 3/ vco triangle wave into cv input, lfo or adsr into new input, +5v into > one i/o socket, 0v or -5v into other - result = second (or third, using > both sections of motm700) pwm wave from single VCO! > > pretty cool, eh? Any thoughts? Anyone fancy getting to work on this? > > please! > > best wishes > -- > norman fay >
Message
Re: [motm] suggested mod for motm700 (longish)
2001-02-10 by J G Wong
Attachments
- No local attachments were found for this message.