Midi to CV converter for Voyager Old School

The Moog Forum Minimoog Forum
1

Hi

I recently took the plunge and bought a Voyager Old School. After getting to grips with it, I now want to sequence it from Logic.

I’m looking at the MP-201 or Kenton pro solo 2.
After some great help here and because it’s a moog product I know the MP-201 will work 100% with the OS. However I’m unlikely to tap into its many other features. Do you think it’s over-kill as just a midi-cv converter?

The SOS review of the Old School has made me weary of the Kenton. However I’ve read a couple of posts stating that it works fine with the Old School.

What do you think?

Thanks

Vin

2

I doubt that very much, there are so many things the MP-201 does above and beyond the call of duty for a midi-to-CV converter. LFO’s and envelopes. With a CV equipped (and non-midi) synthesizer you want to grab just about anything that does CV’s.

Maybe. But again, for all it offers, it’s a mighty piece of equipment. If you’re looking for a lower cost though, there are many good ones. Be careful about reviews. I have seen many reports things that were not entirely true. I tried quite a few of the available midi-to-CV converters. The Kenton I am not crazy about. My own favorite (besides the MP201) is the Doepfer A-190-2, which is a euro rack modular format. There’s an external version of it, in a little box that looks like the Kenton, (nothing looks more like a square box than another square box), different color.

Have fun!

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If you use a MOTU audio interface I’d recommend Silent Way or Volta over both of them. With Silent Way (which is only $50) you get LFOs, envelopes, triggers, gates, CV recording (you can actually record the output from a VX351 for instance and play the CVs back to your Voyager), midi to pitch CV, automatic VCO tuning/scaling and all your settings get saved with your Logic projects. Same with Volta.

4

Just finished reading that SOS review and it seems the Vogayer OS did not respond to a standard 1V/Octave CV on the pitch CV input. That’s why there was a problem controlling the OS from the SH101 and Kenton.
So you would need a MIDI to CV converter that can be scaled to the same volt per octave the OS is scaled to. Not sure what that is though? My Vogager PE is about 1.028 V/Octave.

From the MP-201 spec:

“CV SCALE: This is where you adjust the CV output so that the thing you’re controlling will track pitch correctly. Not everything is scaled to exactly 1V per octave (example: Moog MF102 Ring Mod tends to be around 0.7 V/Octave) - you can choose any scale in the range 0.667 V/Octave to 1.333 V/Octave.”

So the MP-201 would be a good choice. Any MIDI to CV that is locked into 1 V/Octave probably won’t tune properly.

5

I don’t agree. I don’t know nothing about the SOS review but I find the OS perfectly in tune at 1volt per octave.

6

Interesting, perhaps they tested an early revision OS?
Paul Nagle did the review, here is the quote from SOS:

“Unfortunately, it was the incoming pitch-CV response that caused me real problems. Driven by the SH101 or by my Kenton Pro 2000 MIDI-to-CV converter, the Old School did not track accurately at all. Moog inform me they decided to omit CV input calibration from the design, and I am advised that the best solution is to use an attenuator from either a VX351 or a Moogerfooger CP251 Control Processor (or a similar module, if you have a modular synth) to tweak the incoming voltage until the Old School plays in tune.
Personally, I can live without patch memories and MIDI control of knobs — but without basic MIDI note reception, I can’t drive those chuggy Moog basses from a sequencer without added cost or complication. At this point my nostalgia transferred briefly to the dawn of MIDI: the solution to exactly this kind of voltage incompatibility.”

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I don’t know. Could be. I have read a pot upgrade from Moog available about that. Didn’t ask about it, don’t need no placebo. Not counting foogers (some are not 1v/oct), Moog 's been manufacturing Voyagers for many years now, with CV inputs, and the spec is 1v/octave “period”. The whole tuning of the instrument depends on it. I don’t see why it would have been different for early OS’s.

I wonder if SOS measured the CV’s from the Kenton and SH101 outputs at all, and passed the bucket to poor old school when they didn’t get the results they expected. Laughable really.

I have measured the Old School CV’s in and the MP-201 CV’s out time and time again, and I am perfectly confident in the gear I own. By the way, the Doepfer A 190-2 is also right on at 1v/oct and drive the OS, guess what… perfectly in tune. :smiling_imp:

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Actually, I am a little bit hyped up about this. This statement is not credible at all. I can’t certify this on the OS (its still under warranty loll) but on vintage gear, the CV in voltage on the pitch input jack is directly coupled with the internal running keyboard voltage. Calibration here makes no sense at all. Not needed. The VX 351 \ CP-251 thing makes even less sense. True, you can use knobs on the CP-251 to offset CV’s or attenuate them, but this is done in an unprecise manner, for experimental uses and effects. Why would you engineer one of the best synth ever, and have people calibrate the tuning of their instrument by twisting knobs with CV’s in and adjust by ear??? This defeats the whole purpose of engineering a standard.

The more I study the OS, it’s a little marvel of analog electronics precision. The whole thing can’t be. Nahh my guess is more simple. Support call was fed that day to a young support service person (i bet not an engineer of those circuits), who, after skating a little, caught off guard, fed him the calibration bit, and probably hanged up the phone all proud, thinking : “Ha, I told him how he needed a CP-251 and more gear”. Problem is the thing un-ravelled in print and people have a tendency to read these.

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Hey Vin, I too have an Old School and just picked up the MP-201. Believe me, it’s uses are well beyond what it appears at the surface yet not too far out there as to be unusable.

I was going to purchase a CP-201 a few months back (already have a VX-351) but instead opted for the utility of the MP as it serves some of the same functions from a LFO perspective so aside from being a great general purpose expression pedal on steroids (it certainly put the clamps on the # of pedals that I was accumulating), it also serves as a sync point for modulation and [for me], syncs my Logic clock with an LFO out for S+H waveforms into the Old School.

Sure there are times that you want full control over the LFO, but others where having it in Sync is handy.

I’ve got a Phatty with CV outs as well and a FreqBox that I’ve turned into an OSC that I’ve been playing with but with all of these new toys, I have to say that I have not yet attempted the Midi-CV for the sake of playing back sequences but I"ll be getting to this next.

If you have something specific that you need some feedback on and would like me to test it, let me know. Per CZ-Rider’s advice, the option to tweak the voltage at the Pedal is gold. I wouldn’t look any further than the MP.

-Mike W. from NJ

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Portamental: Thanks for the heads-up on the Doepfer, the little box version, MCV4, is cheaper than the Kenton. Cost is a factor, as despite getting the OS for good price, it was more than I should have spent!

jon_kull: I don’t have a MOTU interface, I looked into Volta, but my interface isn’t compatible. It sounds like a great solution, but a new interface and the software is more than I want to pay!

CZ Rider/Portamental: Despite having bought my first synth in '92, CV/Gate is new to me! So I’m depending on reviews and this forum for advice. Sounds like the SOS guy had a genuine issue, but perhaps it was his specific Old School.

MikeWfromNJ: Perhaps I would end up experimenting with the MP-201 and finding it of use. I’ve never used any kind of foot controller, maybe it would be fun.

I think the overall consensus is that the MP-201 is the better of my two options but that the Kenton/Doepfer should work fine too. The Doepfer is €280 cheaper, which is significant. I could pick up a old synth for that or a couple of soft-synths. I’m going to think about it for a while longer. The main thing is I’m more informed than I was.

Thanks

Vin

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I should get delivery today on a MIDI to CV converter today. It only works on channel 1 but gives 1V/oct, velocity, gate and trigger out. $185USD. I’ll post up how well it works later.

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[/quote]The more I study the OS, it’s a little marvel of analog electronics precision. The whole thing can’t be. Nahh my guess is more simple. Support call was fed that day to a young support service person (i bet not an engineer of those circuits), who, after skating a little, caught off guard, fed him the calibration bit, and probably hanged up the phone all proud, thinking : “Ha, I told him how he needed a CP-251 and more gear”. Problem is the thing un-ravelled in print and people have a tendency to read these.[/quote]

I own a Voyager Old School (I will hereafter refer to it as a Model E), and it is by far my favorite synthesizer I’ve ever used. I actually sold a Macbeth M5N to buy it because I prefer the sound and user interface of the Model E, at least for making music (the M5N is superior at making incredibly complex sound effects).

When I read Paul Nagle’s review of the Old School, I was very surprised that his review model didn’t track accurately with a Kenton Pro 2000. I had been using a Kenton USB Solo to sequence my Model E for months, and it seemed fine to me. I decided to check it out with a guitar tuner, and I was shocked to see that it actually wasn’t tracking well at all! I couldn’t believe that I hadn’t noticed it before, but I realized that it was because I was actually enjoying the slightly out-of-tune effect it had on my sequences. Anyway, I called Moog Music about it, and they were really helpful and informative about the issue. They said that the PITCH input in the CONTROL INPUTS section is definitely not calibrated to track at 1v/octave but that I might be able to pay for a mod to make it work with a sequencer that way. Here is what Rosser Douglas (a very nice Moog Music employee) wrote back to me about that mod the following day:

“We can mod your Voyager so that you can tune it to track 1V/octave indefinitely. This requires removing a resistor, and replacing it with a smaller value resistor tied to a variable resistor in series. This is something that you could do if you please, but it does require some experience to be able to do it cleanly without causing damage to any other part of the board.”

He hasn’t gotten back to me on how much the process will cost, but I’m sure I’m going to end up doing it. The Moog Voyager Old School does not track properly with an external sequencer at 1v/octave. Paul Nagle was right, and his suggestion to “use an attenuator from either a VX351 or a Moogerfooger CP251 Control Processor” is exactly what Moog Music told me to do too. If for some reason your Old School actually does track properly, Portamental, you are a very lucky exception to what the rest of us Model E owners have to deal with. It’s really not that big of a deal to me since I don’t use sequences very often, but I am looking forward to having it corrected. I wouldn’t trade my Model E for anything. I love it!

Now if I could only replace that smoothed S&H waveform with a ramp wave, use OSC 3’s level in the MIXER section to control the depth of the 3-1 FM switch, adjust the keyboard’s over-sensitivity to velocity, vastly extend the upper and lower range of the LFO rate, invert the VOL input in the CONTROL INPUTS section so that increasing the modulation depth preserves the original volume at the peaks and drops it lower at the nadirs, and modulate the waveform of only one oscillator at a time…

13

I would think at least some of that issue could be resolved using the internal editing functions of the Kenton for course tuning, fine tuning, and scale.

Check out pages 6 and 7 of the Kenton manual.

http://www.kentonuk.com/kmanualspdf/usbsolo.pdf

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For the record, I bought the doepfer and found it troublesome. I couldn’t get it to track properly all the time. More importantly it took forever to get it working. Perhaps more down to me than it. I eventually bought the MP-201, it works perfectly every time, no hassles. So far anyhow

cheers

Vin

15

David,
This is off topic, but I wish that the modulation amount could be set as a destination.

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I hear that, EricK. It would be great to be able to modulate modulation depth. Actually, you can kind of do this if you have the VX-351 Expander (or some other repeatable external gate trigger). It’s not quite what you’re talking about, but you might be interested in trying this out:

Send one of the VX-351’s LFO outs (either triangle or square) into the GATE input in the ENV section, and switch the ENV GATE to ON/EXTERNAL. Set the LFO rate to about 40%, set OSC 3 to LO (set it to a triangle wave and switch it to OCTAVE 1’), turn off all oscillators except for 2 in the MIXER section, and set MOD BUS 1 to:
SOURCE - OSC 3
DESTINATION - OSC 2
CONTROLLER - FILT ENV
AMOUNT - 50%

Next, open the filter all the way, and then set the FILTER envelope to:
ATTACK - 75%
DECAY - 0%
SUSTAIN - 0%
RELEASE - 75%
AMOUNT TO FILTER - 75%

Set the VOLUME envelope to:
ATTACK - 0%
DECAY - 0%
SUSTAIN - 100%
RELEASE - 100%

And remember to switch that ENV GATE to ON/EXTERNAL. Now, if I’ve written this all correctly and you’ve followed it all correctly, you should have a droning tone which sounds like it’s being modulated by an LFO which is modulating the depth of another LFO. You can speed it up and slow it down with the LFO rate, but you’ll have to also adjust the envelope settings to get it to sound right. If you experiment with different knob settings and modulation routes you’ll find that there are actually a lot of interesting sounds to be found in this vein.

I know it’s not quite as cool as being able to actually modulate modulation depth, but it’s at least a step in that direction. Enjoy!

17

this whole 1V/octave thing is a nightmare with both the Voyager and Phatty
There is no way I can use them with a Roland MC-4 until we get the service information

kenton suggest with usb/pro solo Use parameter #14 to adjust the scale. Going in a minus direction will
allow you to adjust the scale as required. See info on tuning in the
manual.

Still any form of midi is nowhere as good as the same sequence programed on Roland MC-4
For Roland MC-4 owners this may interest you

http://www.youtube.com/watch?v=e9B4WQHql0w

18

Hi,
Kenton USB solo will let one fine-tune voltages for general pitch and scaling and save the lot to memory.
-Sid