Amotz was asking about eliminating phasing artifacts he was hearing when listening to two oscillators in unison on his Voyager. So I did some playing around on my Voyager and discovered that if I tried tuning osc 2 or 3 in unison with osc 1, I could get close, but the phasing would still occur.
Today, I tried tuning osc 2 and 3 in unison with each other, leaving out osc 1, and discovered that 1 & 2 not only tuned in unison, but that they actually seem to lock in with each other whenever I even got close to unison. It’s as if they have a PLL circuit, as they sound like they’re locking in phase with each other every time! And they stay in unison, provided the synth is warmed up. They don’t waver at all, even if I shut the synth off and then turn it back on. Another interesting thing is that if you change the octave settings of the two oscs while they are locked up, you can actually hear them go out of tune for a split second, but then snap back into tune almost immediately as you switch one or the other into the same octave setting! It’s especially noticeable switching them from 8’ to 4’, or 4’ to 8’ while listening.
Unfortunately, I cannot seem to get osc 1 to do the same with the other two.
In any event, I hope this solves your problem Amotz.
It seems that I can now get osc 1 to cooperate… sort of.
While oscs 2 & 3 seem to lockup pretty quickly, osc 1 needs you to get closer to unison before it will finally decide to lock with 2 or 3. Even changing the octaves on 1 & 2 or 1 & 3 produces the same phenomenon where you can hear them phase out, phase in, and then lock.
The only problem is that I let a note play on osc 1 & 3 for over 23 minutes, and they lost and regained phase lock 5 times within that time period. Playing the same note on osc 2 & 3 produced no glitches within the same time period.
So, while osc 1 will lock with 2 or 3, it is not reliable, and is tricky to lock up in the first place. However, oscs 2 & 3 will lock up relatively easy, and will hold lock for at least 23 minutes.
I just read something about oscillators having a tendency to soft sych with each other if they’re on the same power supply. I wonder how that works, and if that’s what’s happening here?
Amos told me that the Voyager has a mechanism to prevent accidental detuning. Maybe this is what you’re experiencing here. At a later date, Rudi told me that it also has 14-bit resolution and no matter what you do, the detuning is not very precise as, for instance, in the A6. Try it: +3 or +4 in the frequency knob and there is already too much detuning. If you use the Editor you can get more precise detuning, but you can’t do this live.
I have been bugging Moog for ages to come up with an idea to have more precise detuning available from the front panel directly, but no luck.
I didn’t think this thread was very interesting when I first read it, but now I get it. The Voyager is way too easy to get in tune. Real analog should either drift slightly over time or at least give you a lot of freedom in subtle detuning. After years of living with perfect digital tuning, it never occured to me that the voyager oscillators are deliberately locking. We really need fine tuning and an optional lock-free tuning mode. But these things are pretty much set in the hardware.
