Another Really Simple Voyager Mod.

Tips and techniques for Minimoog Analog Synthesizers
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Markyboard
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Another Really Simple Voyager Mod.

Post by Markyboard » Mon Jul 29, 2019 12:41 pm

Bottom Line:
Modified Pitch CV output includes pitch bend, glide and all oscillator 1/2 modulations.

Background:
I’ve never seen this posted anywhere but apologies if this has been discussed here before. Those using the Voyager to control modular and/or semi-modular gear may really like this. Up until now I’ve used the Voyager midi-ed to a MP-201 pedal to control one of my modular skiffs and a SEM (non-midi). 3 of the 4 CV outputs from the MP-201 are used to provide pitch, gate, and expression. The SEM does not have a glide/portamento function. However the MP-201 does and adds it to the converted midi note data which appears on the CV output set up for pitch. The problem (at least for me) is there’s no way to change the glide setting in real time with another controller. And with the pedal on the floor editing is not very convenient. I’d really like to use the Voyager glide knob for this which transmits CC5… but no dice.

More blah blah blah:
I tried some other options including using the Voyager CVs via the VX-351. No luck as the Pitch CV output is not only “glideless” but also does not add in the pitch bend modulation. I knew this going in but…well ok, I’m trying to build some drama here.

Next I tried controlling the SEM with my 0-Coast which has a midi to CV converter with pitch and gate outputs. Surprisingly this works great and you can control the glide from the Voyager using its glide knob transmitting CC5. Almost end of story but … I started thinking how round about this is; Voyager >> midi interface>> PC>>midi interface>>O-Coast>> SEM. Not exactly intuitive when patching up the modular.

Getting to the Point - Finally:

Wouldn’t it be nice if the Voyager just put glide on the pitch CV output? And pitch bend? Well it does now. I found the modulated pitch control signal that goes to the Voyager oscillators and rewired the DB25 accessory port to use that signal. Really simple – cut 1 trace and add one alternate wire.

Anyone Still With Me?

There is one caveat; the pitch CV output is now greater than 1V/octave so you will need to run it through an attenuator first. Fortunately, the VX-351 has a couple of these as does the CP-251 (edit – err never mind CP-251, not enough positive range). Once adjusted the tracking is pretty good though maybe not quite as accurate as the internal tracking of the Voyager which that signal is calibrated for. Had there been a spare op-amp driver I would have added a circuit with a trim pot for internal calibration. But no matter, calibrating externally with an attenuator might still be the best approach.

But Wait…There’s More:

Not only do I get glide and pitch bend but also anything else that’s modulating pitch (on oscillators 1 and 2). This includes anything on the mod buses that’s routed to pitch -all controlled direct from the Voyager. This is way cool. I realize all these modulation components are available as individual outputs and can be combined with some effort and the right modules. But it really is nice having this built into the pitch out CV. That’s it.

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ummagumma
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Re: Another Really Simple Voyager Mod.

Post by ummagumma » Mon Aug 05, 2019 9:52 pm

that sounds intriguing, do you have any pics showing the wiring?

Markyboard
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Re: Another Really Simple Voyager Mod.

Post by Markyboard » Tue Aug 06, 2019 5:44 am

Here are a couple of pics. I forgot to snap a pic after modifying the modification and so did a photo edit. My original attempt worked with the glide but not the pitch bend. If you recall Moog offered a modification to the filter keyboard tracking such that it would be affected by glide and pitch bend. This is the the signal I originally tapped off of for the Pitch CV modification but I suspect the pitch bend component is too weak at this point before further amplification downstream in the filter section.

No matter, this latest incarnation taps off the final modulation signal going to Oscillator 1 and 2 which allows for many more modulation possibilities.
Remember you do this at your own risk. Probably not too many folks using a Voyager to control external modular gear but with this mod I'm finding it to be an excellent controller.

Image
Image
Last edited by Markyboard on Tue Aug 06, 2019 10:55 am, edited 1 time in total.

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ummagumma
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Re: Another Really Simple Voyager Mod.

Post by ummagumma » Tue Aug 06, 2019 10:42 am

thanks!!

that is super useful, and that is exactly what I plan on doing with my Voyager: interfacing with 5U modular

ps if you have any clues to where I could tap into the "spacing" CV, I have been wanting to add a CV in for that, as well

Markyboard
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Re: Another Really Simple Voyager Mod.

Post by Markyboard » Tue Aug 06, 2019 3:33 pm

This should help...


Image

:o

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ummagumma
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Re: Another Really Simple Voyager Mod.

Post by ummagumma » Tue Aug 06, 2019 5:10 pm

wow!!

that is the white unicorn I have been searching for...thank you!!

1. so for spacing CV in, I need to interrupt those two points with a 1/4" jack?

2. and for your glide CV out, tap off the original point in your post above?

3. for all modulations going to OSC 1 & 2, tap off the 2nd revised point in your post above?

if there is no need to use the VX351, you don't need to cut the trace ( for example I have a Voyager XL, and there is plenty of room on the patch panel to add a few 1/4 jacks ), correct?

and I suppose ground would be the sleeve of the 1/4" jack, tip being the signal

*edited* as pitch bend wasn't included in #2, just glide
Last edited by ummagumma on Tue Aug 06, 2019 5:21 pm, edited 1 time in total.

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ummagumma
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Re: Another Really Simple Voyager Mod.

Post by ummagumma » Tue Aug 06, 2019 5:17 pm

hmm: for spacing CV in, should it be a switching jack? so if there is no cable plugged in, the circuit is continuous?

Markyboard
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Re: Another Really Simple Voyager Mod

Post by Markyboard » Tue Aug 06, 2019 6:42 pm

ummagumma wrote:wow!!

that is the white unicorn I have been searching for...thank you!!

1. so for spacing CV in, I need to interrupt those two points with a 1/4" jack?


Oh sorry- if you look really close you’ll see both those solder nodes are connected. So which ever one you find easier to solder to. If you’re adding a jack I suggest adding in a series resistor. And a 5V pull up if you want to control it with an expression pedal. And of course ground the jack sleeve connection. I was just showing where to access that spacing signal, not how to do whatever you’re trying to do :wink:

ummagumma wrote:
2. and for your glide CV out, tap off the original point in your post above?


Not sure I understand the question. You’ll solder one end of your alternate wire to a new jack tip instead of the accessory connector as I have done. The other end still connects to R51 ( top end point of the drawn in alt wire)

ummagumma wrote:3. for all modulations going to OSC 1 & 2, tap off the 2nd revised point in your post above?

Exactly.


if there is no need to use the VX351, you don't need to cut the trace ( for example I have a Voyager XL, and there is plenty of room on the patch panel to add a few 1/4 jacks ), correct?

and I suppose ground would be the sleeve of the 1/4" jack, tip being the signal

*edited* as pitch bend wasn't included in #2, just glide



Ah...yes, forgot you have the XL. No need to cut the trace since you’re adding a new jack. And yes, ground the sleeve. Btw I’m not sure what if any other differences may be present in the xl verse standard Voyager.

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ummagumma
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Re: Another Really Simple Voyager Mod.

Post by ummagumma » Tue Aug 06, 2019 8:33 pm

that is great information, thanks again!

I owe you a beer, if ever we meet

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