Pedal Modulation source = Prog, where prog is set to “filter envelope”
Pedal Modulation destination = Noise amplitude
Pedal Modulation shaper = Prog, where prog is set to “offset”
Amount = max
What I expected is a complete modulation of noise amplitude following filter envelope.
Instead we obtain a slight amplitude modulation hardly perceptible. Same thing if destination is one of three VCO amplitude and nothing change with different off-set values in shaper.
Why?
Seems to me this features if well implemented represent a strong way to make dynamic and interesting evolution in sound.
This is actually normal - I can’t remember if this is explicitly stated in the manual or not. Basically if you are modulating the Mixer levels, they are expecting a +/-5 CV to set the levels all the way from min (off) to Max (full volume)
The EGRs are a 0 to +5 Volt signal, even when routed through the Mod bus. The way the modulation of the mixer levels is set up, zero volts is COMBINED with the mixer level - so if the Mixer level is set to 0 then you always have no signal - if you set the mixer level to 5, then the EGR can add on top of that, but not ever turn off the audio all the way.
The easiest way to hear this is to init. parameters, then set PGM Mod Wheel Source to Filt. Env., Set PGM Mod Wheel Dest. TO osc. 1, set Shaping to ON, then set Mod Wheel Amount to 10. and turn up the Mod Wheel. Set the Filt. Env. Amount to center so it is not affecting the Filter, then set the filter attack to a medium long time. decay to short as possible, and Filt Sustain to 0. You can hear that this modulation path DOES affect the amplitude of the signal through the mixer level, but doesn’t offer 100% modulation depth. Try it again with the Triangle wave as the source modulating Osc. 1 level and you’ll hear that the +/- Triangle wave signal shuts of the mixer level VCA. Again - a limitation of the analog hardware.
I hope this makes sense…but it is a limitation of the hardware, not software.
Anyhow if you have a VX-351, you can get past this - simply patch the Filter envelope out into the Voyager’s MOD2 input (MOD2 accepts 0V to+5V input and will output to the analog board a -5V to +5V signal), select On/MOD2 as the Mod Source, and the mixer level as destination… Note that the curve of the control input for the Mixer levels isn’t compensated to accept a linear input, so the volume seems to turn off before the Filter Envelope signal gets close to zero.
I doubted there was a problem wit voltage swing. It is quite clear if you use the same set-up for
modulating the panorama. Audio signal move from center to the right side but never fro left to right.
But for this reason I expected the offset parameter in modulation shaping can assign for negative values a negative portion in control voltage. Clearly if D to A converters are only able to produce positive voltage signals there isn’t possibility to modulate in other quadrant. In case specific of VCOs amplitude and noise amplitude the error reside in the combination of both signals the one produced from potentiometer and the other coming from D to A. Clearly is a sort of product and sum instead of a simply sum. If it was a sum with amplitude potentiometer at zero and the D to A swinging from 0 to + 5V we obtain exactly what we expected an amplitude modulation fro 0 to max. Instead in this condition we obtain pot + pot*mod so when pot = 0 all is 0 when pot = 1 = max we obtain 1 + mod and mod is practically unnoticeable. I don’t know schematics of voyager and consequently interaction between hardware parts an software but I think there is some mistake or strange approach because so done an interesting part of modulation path is practically unusable.
I hope some solution can be found in software because it is easy to update.
Yes, there are some interesting modulation possibilities that the hardware can’t fully exploit. With the shaping, you have a similar situation as described regarding the modulation of mixer levels, except the shaping would be in relation to the Mod Amount control (rides on top of the gain set by Mod Amount)… Beyond that there is no way to bias the modulation signals themselves - there just aren’t any hardware hooks to do that. You have only the routing and gain controllable internally.
Even with the hardware limitations of the mod busses - they are deep and powerful synthesis tools. You can come up with some really interesting modulations - such as a Synced Osc.2 amplitude modulating Osc. 3, or noise modulation of an oscillator level (a different quality than noise mod of pitch - more breathy) or Osc.1 sawtooth modulating the filter resonance or audio rate modulation of pan - far more modulation possibilities than on the original minimoog…
I have yet to try everything. I never get bored trying…
Yes I’m agree with you regard the others possibility of modulation bus.
The Voyager is in any case a fantastic sounding machine and any time
I put my hand in his keyboard I’m happy for money spent. If I think to very limited modulation possibility of model D the Voyager is a fantastic jump. But in Italy we said “hunger come eating”.
