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
>