OBERHEIM SYNTH

I found in some of the factory patches, e.g. "POLYSYNTH" modulator RAMP to be routed to destinations like ENV1 ATTACK, VCF RES with maximum or considerable modulation factor and the RAMP set to RATE=0 (instantaneous) and SINGLE (trigger). Any setting of RATE >0 leads to drastic effects on each of the modulation destinations, in particular on RES (modulation=63). But what does the RAMP do with RATE set to 0? I cannot hear any difference, if the RAMP modulator is turned off or deleted from the modulation matrix.

Now, this puzzles me. What is the effect of applying RAMP=0 w/max. modulation (63/-63) on any destination parameter? Is it just to introduce some kind of glitch or uncertainty to the destined parameters (due to the slow processing speed of the voiceboard CPU)?

Who of the sound programming geeks out there might give me the right explanation?

(Else, I will hook up the Synth to my Oscilloscope to analyse the RAMP modulation issue.)

Thank you for your help.

I tried the resonance modulation setting that the OP was describing and found that nothing happened at all when ramp rate was set to 0/mod amount was 63. What "should" happen?

Regarding the ramp speed, a fast ramp never sounds any faster than the regular envelope setting. I think there is a software and hardware limit as to how fast either the ramp or envelope can ever be. There is an untested hardware mod (described over on the Xpantastic group) that should speed up the envelope attack time, but no one has tried it yet.

One trick I did find, while messing around with the ramp mod mentioned above, was that if you modulate the resonance with the same zero attack/low decay time envelope as the filter cutoff (with resonance already set fairly high and mod = 63) this adds a slightly sustained self-oscillating "snap" at the beginning of the envelope. This emphasizes the attack a bit more and gives it more perceived punch. Kind of like how the minimoog envelope "hold" flaw works.