when I get some time, I plan to research & see if these are possible:
add a CV in, to control the Filter Spacing ( I dislike having to tie up a mod matrix, just to do this )
add a switch to disable each OSC 1,2,3 PWM/WAVE shaping ( right now it’s a global control that affects all 3 OSC )
add CV in, for PWM/WAVE mod of each oscillator
Something else I really like about the model D reissue, is the LFO control down by the mod wheels. Being able to ride the mod wheel, pitch wheel, and LFO speed with one hand is super flexible. Have been thinking about adding that to the Voyager…although a foot pedal controller could accomplish the same. Not as “handy” to use though!
build an authentic CP3 mixer circuit, on it’s own board. figure out how to interrupt the signal between the digital board ( which handles the pot information ) and the stock mixer circuit
install a toggle switch for “vintage” and “modern” mixer circuits. Then you would have the stock Voyager sounds ( and all the existing presets ) but also be able to use the dirty CP3 vintage style mixer, instead. Would be interesting to run some of the presets through, too
the stock mixer circuit on the Voyager is probably on an IC…but it should still be possible to switch between them?
Funny I was just checking the back of the Voyager for a Spacing CV input the other day. I couldn’t remember if it had one. But as long as there’s midi CC control I don’t find much if any additional value adding a direct CV.
yes, that document by Don Solaris it is what made me think individual OSC PWM control may be possible
my goal is to improve CV interfacing with other modular gear, and even the Voyager itself.
MIDI CC for spacing would involve too much extra equipment, I think? I would need another controller, plus a MIDI to CV converter
Although I wonder: has anyone setup a CV—>MIDI device, that has direct access to all the Voyager’s CC parameters?
the MIDI step values might be audible, in some parameter sweeps. Turning off the Voyager parameter display increases it’s internal resolution, but I doubt that would apply to external MIDI?
There is one device I konw you already have that takes in CV and transmits midi; the Voyager! Send a CV into Mod 1 or Mod 2 and it transmits midi out. I realize this defeats the purpose since you already stated you don’t want to give up a mod bus. But there are lot’s of other boards with CV >> midi out capability although we think of them strictly as expression pedal inputs. So you may already have something available. For a dedicated device maybe Kenton has something?
I just tried it - works great. You do have to use one of the mod buses but since you’re not using them for the spacing control maybe you can use one of them for this .
If you’re still determined to modify the hardware then it sounds like you’ll want to switch out the Wave In Jack as opposed to either one of the bus inputs since independent CV control is your main concern. Should be just as easy and you could add 3 switches ( or multi pole switch) for complete independent CV waveform control of each oscillator. I would recommend grounding the NO contact of the switch so as not to introduce noise into that input of the Op-Amp. Not sure why Don didn’t do that.
Edit: Sorry Uma - just re-read your last post and repeated much of the same idea you stated. It sounds like we’re on the same page
If you use the authentic CP3 circuit, it would not be controllable via existing knobs or by the patch memory. You you would need a brake-out box and use a CP3 mixer external and feed it back to the Voyager via the external audio input.
And remember: part of the CP3 magic is caused by the amplitude of the ingoing Moog 901 oscillators. If you use 921 oscillators, a CP3 changes the sound in a different way.
Yes, the real problem is no schematics or knowledge of how the Voyager works internally. I am just trying to imagine how to make a vintage style mixer switchable with the stock one, and guessing at how the digital pots feed the analog ( I assume? ) mixer
I have been exerimenting with FX/external distortion/mixers/drive, but have not found anything I like in the Voyager mix/out loop.
In fact the mixer is not a normal mixer but a array of summing VCA.
The knobs are just doing a drop in voltage.
A multiplexed A/D measures every pot voltage many times a second.
The digital numbers representing the knob position are only used, if there is a certain amount of change since the last loading of a patch. Otherwise the stored virtual knob position number is used. This virtual or real nob position number is than used by a multiplexed D/A to send to the nalaog sound generating board. Also all other informations like MIDI or keyboard notes are D/Aed and sent to the analog board. The analog board got 57 CV controlled parameters. Every continues knob on the front panel is a CV. And there are switched that are controlled by the digital board.
So even the resonance and the individual stages of the envelopes are CV controlled on the Voyager.
So the mixer knobs are in no way connected to the mixer electronics. The mixer just receives more or less steady analog CVs generated from the digital board (by the knob position or the stored patch data). So the mixer knob of VCO 1 is in fact a VCA. And all the mixers channels VCAs are then summed together in a static manner.
All this mixer thing is more or less like on all synths with digital patch memory and real analog sound generating.
You can do a break-out of the signal of the VCA channels of the mixer and change it by some Op-amps to get the right level to mix their signal in a CP3 like mixer (that would be set on a fixed all open position to use patch memory). And then lower the CP3 signal and feed it into the external audio in of the Voyager. I would do this only with the oscillators signal and the noise. The external signal would be untouched on the Voyager’s mixer.
Finding the needed points to get the signal would be no problem (but will take some time) if you got a scope and take the needed precautions when working on running opened electronics.
in light of all that, it wouldn’t be much different than just using the mix out/insert to run thru a CP3 style circuit/effect
I was hoping to get individual OSC/noise/ext level control, thru the CP3. Similar to the Grandmother/D mixers & how they interact
Actually I guess you WOULD have control over the individual OSC/noise, but then they would be summed and fed into the EXT. And you would not be able to use the EXT on its own, with other sources?
ps your op-amp dropping note makes me think that perhaps the mix/out I have been feeding my FX needs to be attenuated
I am somewhat embarrassed to admit, that I have been using the wrong mix out/insert cable, in my efforts
I built the mix out/insert cable described in Knobtweaks: which sends the voyager signal back into itself, and acts as a breakout so you can tap the signal and run it through external effects. I have been feeding this into various devices, and returning it via the EXT in, blending it with the original OSC’s in the voyager mixer
Well, just using a regular Y stereo–>2x mono cable lets you run the voyager OSC’s through effects, and back into the synth, with no need to do any of that. Or use the EXT in. No wonder I was dissatisfied with the sounds I was getting…I was only blending in effects via the mixer, and not modifying the internal OSC sound at all
( the apple hit me on the head while I was trying to attenuate the mix/out signal via the CP251/XL front panel, to bring the signal down & be more “guitar pedal” friendly. I realized I could just feed a Y cable through the pedal itself )
Don’t be embarrassed because it’s not quite what you say. Using the Knobtweak cable provides 2 paths for the oscillators to get to the filter; The mix output using the tip (send) /ring (return) is direct (I.e. no feedback on its own) and the other path tip/send only which is fed back through the external input creating a mixer feed back loop. Once the mixer starts feeding back the direct signal is also affected. It’s not like it’s bypassing the feed back loop. So you can’t really claim to be mixing a clean signal and a feedback signal. Yes they blend but not the way you’d expect. And it’s very much dependent on the mixer levels which affects both paths (send/return and external input).
Using a conventional Y-cable is perfect for Integrating external effects so good on you for resolving your issue. Btw the original mini feedback trick uses the post filter output signal. So you need to connect the L/R output or the headphone output to the external input. Not sure how much goodness you get from just mixer feedback as provided by the knobtweak cable.
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