I got my Voyager OS back from Moog Music this afternoon and this is the 1st day of really getting to know the instrument. (I sent to Moog Music because Oscillator 2 was dead, out of the box) I was messing with the spacing and notice that when I sweep to the right the sound sweeps on the left and vice versa. When I plug the headphones into the Voyager then when I sweep right the sound sweeps on the right side and sweep left, the sound sounds sweeps on the left. That makes more sense to me but why is It that the headphone outs and main outs are reversed? I checked my cables and tried two different mixers to make certain I did not have the audio outs backwards. Anyone else notice this with their Voyager OS?
No, if that is so on mine too, I have never noticed. One thing that I noticed right away and that is working reverse on my OS, or maybe more accurately mis-labelled is KB gate and pitch out, since pitch is gate and vice-versa. No big deal, but you have to know when patching.
I spoke to Perry in tech support at Moog Music today and asked about the audio being being reversed in the headphones compared to the main outs. Off hand he thought that was the way it is, a quirk of the Voyager OS. He said he would check and get back with me to confirm.
I had not heard anything back on that issue.
I’d be curious to know if that’s also the case on regular Voyagers too ? Not that it’s such a big deal… Since one could simply open the back panel, and reverse the red and white wires on the 1/4" TRS female headphone jack connector. But not if it’s still under warranty, though, as this would cancel it.
I suppose they could do a re-wire. I actually thought the way the sound was positioned with the filter spacing in the headphones sounded correct or more logical verses the main outs. Oh well, right now I am using the main outs as stereo but I could just either use a mono connection or not bother with the filter spacing knob.
Well, it’s much easier to reverse to output jacks to match the headphones out… 
Also could just reverse the outputs connected to the mixer.
That’s what I meant; switch the output cords around. 
Yep that makes since now.. I am curious if it does this on the other Voyagers too and what quirks they may have in general. I would like to get a Voyager select but sometime in the future maybe.
I finally made the test. Same results as you. The way I interpret the book, the main outputs are reversed and the headphones are normal.
While this is a ‘bug’, if you use both outputs on a regular basis, just plugging the outputs reverse is an acceptable workaround. It is to me a better option than sending the synth for repair, or even do it yourself. I never opened the back panel to see if an easy fix is possible, but again, the workaround makes the situation entirely tolerable.
@Portamental:
Do you have a Voyager OS?
Thanks for confirming this on your Voyager. I was curious as I am getting to know the ends and outs of my Voyager OS.
If you use the pan jack on the rear is that backwards in regards to the outs too?
Logically, since the user manual doesn’t specify if the sound should pan to the right or to the left when an expression pedal is pressed down, there’s no “wrong” way… But the “right” and “left” audio output on the back will still be inverted in regards to the headphones…
The manual states that the effective input range is -5 to +5V, where -5V = fully left and +5= Fully right. I have no way to try it at the moment.
Oooops, you’re right. 
I had missed that on page 30, sorry about that.
But it also says: “Note also that you will not be able to pan left with the pedal without additional offset programming because the expression pedal voltage does not go below 0V.”
Yes.
The Pan jack works as advertised, pans left for negative voltages and right for positive. That’s for the headphones, The effect is reversed for the outputs, which is normal since they are indeed reversed. The pan test confirms the reversal. Testing that was easy with the CP-251.
There’s something that is (sort of) conceptually limited with the way the pan jack works. A full swing from -5 to +5 volts is not easy to achieve with an expression pedal. The CP-251 attenuator will reverse voltage, but then you have to use the CP-251’s knob, so with the attenuator will give you either -5 to 0, or 0 to +5. You can always use the mixer instead, and set the offset to -2.5, for a -2.5 to +2.5 voltage swing, thus not the full pan.
I always thought the CP-251 should have a voltage amplifier. This would be useful, for example, for fine tuning an incoming pitch CV that is a bit short of 1v/oct. It would also allow a -5 to 5 voltage swing using an expression pedal only, as opposed to twisting the knob of the attenuator/inverter.
There is a workaround though. This is one of the best little known secret of the CP-251 that I have never seen documented anywhere. There is a way to double the voltage on the CP-251 by plugging the voltage source (or expression pedal) into the mult, and double patch the output of the mult to both Input 1 and 2 of the mixer (3 and 4 would also work). Clipping (it seems) does not occur as the mixer is able to deal with 10 volts. I would have to check with a multimeter, but with from the headphones, i sounds like full pan. Come to think of it, tripling the voltage could also be achieved using the three mult outputs, maybe with some attenuation to keep voltage safely under 10 volts.
So all in all, full pan can be achieved with an expression pedal only (or with CP-251’s LFO) and the CP-251, albeit with a rather complex patch that monopolizes two or three sections of the CP-251.
I guess my next step will be to implement that technique with the fourth CV of the Step64 for a sequence that swings full left and right at every note (or a more gradual pan too) 
Thanks for sharing that. I sold my CP-251 a few months back and regret it. So it’s on my list to get again since I got the Voyager OS.