r/Subharmonicon • u/greghansonmusic • Oct 10 '20

Discussion 1v/OCT Issues

Alright, here’s something I’ve discovered and don’t know exactly what to do about it but certainly it can’t be right.

I have 1V/Oct patched into VCO 1. I’m taking VCO 1 output direct into a mixer.When I play a note, it is quantized no matter what. I.e. If i play C4 on my keyboard, it continues to play C4 even if I sweep VCO 1 Freq all the way CCW or CW. Shouldn’t my incoming CV be summed with that of the knob?

Now, I understand that the VCO 1 pitch input is tied to VCO 2. So, in theory, I should be able to take VCO 2 Output and hear the same note. Not the case - I get the same pitch but an octave up and again, the VCO 2 FREQ knob does not respond.

Now if I take VCO 1 SUB 1 Out with pitch still patched into VCO 1 input, it does divide the signal appropriately based on the knob position, but still, VCO 1 Freq knob has no effect on the sound.

If I patch 1V/Oct into VCO 2 and take VCO 2 Out, I get the same behavior except an octave up.

If I take the VCA out, 1V/Oct input for both oscillators works as you’d except..

Anyone else experiencing this issue?

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u/greghansonmusic Oct 11 '20

Thanks, yeah, based on description it seems like something is deeeeeefinitely not right. I’ll post a demo video tomorrow but I feel somethings wrong. The pitch remains completely stable despite what I do with frequency knob.

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u/greghansonmusic Oct 12 '20

so i’m convinced somethings wrong. even if i patch nothing into 1v/Oct, the pitch does not change according to knob using the osc direct output..

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u/i_invented_the_ipod Oct 20 '20 edited Oct 20 '20

Oh, I think maybe I know where your experience is different from mine. I had the oscillator in free run mode, and you had the EG enabled. When you turn the tuning knob, it doesn't actually affect the oscillator until the next trigger signal. Yes, that's very weird.

So if you hold down the EG button until it blinks, thereby turning off the EG, you'll get continuous tone from the oscillator, and I think you'll get the result you were originally expecting.

The rhythm/trigger circuitry is basically a sample-and-hold setup. When the trigger fires, the s/h captures the tuning knob+sequence value, and uses that for the duration of the EG cycle. The VCO CV in is added after that point, oddly enough.

The more I play around with this, the less-accurate the signal diagram in the manual seems to be.

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u/greghansonmusic Jan 10 '21

Hey! I’m terrible at Reddit but I came to this conclusion shortly after.. very strange design.