[sdiy] Useful equipment

[mark verbos]

  Why not send an alternating 0v and 1volt from a sequencer. also 
croosfade between the original oscillator square wave and a octave 
devided one. Then you just tweek until you hear no change in frequency.

The arp sequencer has quantized otus making this really effective. i 
guess you do need a DVM to cal the sequencer though....

mark

René Schmitz wrote:

> At 10:46 03.08.02 -0500, Paul Schreiber wrote:
>
>> You guy's are doing it "backwards". You can get a cheap freq counter 
>> for $100 on eBay. As long as
>> the VCO frequency is correct, the 0.000001V on the DVM doesn't 
>> matter. My Kenton Pro-2000 is
>> about 5% off from my Encore Expressionist MIDI-to-CV, but who cares? 
>> [:)]
>>
>
> Well I don't know if this qualifies as "sdrawkcab", but the way I have 
> been doing VCO calibration doesn't involve a DVM. I simply play octave 
> jumps on my controller (usually a Midi2CV interface) doubled by 
> another instrument, and bring the VCO in tune using the normal tune 
> pot for the lower note. Then I calibrate the V/oct setting until the 
> higher note is in tune. Then the cycle repeats, until the right 
> setting is found.
> I also occasionally used a shortcut to this. I feed the VCO into a 
> delay, whose delay time is the same as the octave jumps from my 
> sequencer (via the interface). I mix the VCO with that so that both 
> notes blend into each other. One can easily find the proper setting, 
> as the octaves blending into each other have a characteristic harmonic 
> sound. No need to touch the tuning pots to find the proper v/oct gain. 
> Also it makes it easy to check that gain over the sweep range, by 
> changing the VCO frequency manually. Or by going to two or three 
> octave jumps.
>
> However when calibrating the Midi2CV interface I used a DVM.
>
> Cheers,
> René
>
>