Moog Voyager Oscillator Octave Issues

[JLal]

Hello All,

I'd like to know if any Voyager owners out there have ever experienced twitchy Octave settings on their Oscillators. In my case, when switching feets on the Octave Pots there are times when the screen will show a quick change to an incorrect position and go back to the correct setting. For example, when I change the Octave on Oscillator 3 from 8' to 16', the screen will briefly switch to 32' and immediately go to 16'. Sometimes it happens quickly and disappears, other times, it's more pronounced. On some rare instances, the incorrect setting will stay unless I slightly nudge the pot so that the correct setting appears. The results are reflected in the tone as well - when switching the tone shifts with the change in setting, so the sounds of the Oscillator are jumpy when changing. It happens intermittently with me, and at the end of the day, the Octave settings end up in the correct position.

I am considering sending the analog board to Moog for repair (if it's EVEN that - an associate of mine said it could be) as Oscillator 3 and 2 are showing this behavior, but wanted to run the scenario here and get some input.

My questions are:

1) based on what I shared, could this be a calibration/tuning issue? If not, what could be the culprit?
2) is this something I can fix on my own? - to add context on my skillset: I have no soldering experience, but I am a bit handy with repairs (depending on what it is).

Thanks for taking the time to read this.

[VCO]

I have a voyager . It doesn’t have any of the problems with the octave settings like you were mentioning. I usually have my settings at 32, 16, 1. I do have drifting issues with my voyager. I can get it in tune and it stays in tune once I tune it
upon turning it on. Although if I change the preset to another preset that preset will be out of tune . As long as I don’t change to another preset it will stay in tune with the current preset that I have already tuned. I have OS 3.5. I purchased my voyager used in 2015.

[till]

The display only shows what the panel sends to the digital board. there is no information going from the analog board to the digital board or the display.

If the digital board get bad information due to bad switch contacts or connecting cables, it will pass the unwanted data as CV to the analog board.
So the analog board is not the cause of this problem. It will just react according to this problem.

Check the switch for a good contact. Check the panel to digital board cables and connectors. Also move them while checking them. Check the panel board traces. Check the multiplexer diode matrix or what ever they used in the A/D section. Finally check the PSU in Voltage and use an oscilloscope to find maybe voltage peaks and alike, if the other points did not discover a problem.

As you have to check these things while the Voyager is connected to mains, this is nothing to do yourself, unless you know what you do and your precautions needed. Do at your own risk. Better find some electronic technician to check this for you. A person able to repair radios should be helpful, even if they are not specialist on synths. But this is nothing synth specific to check.

[JLal]

Thank you both for your responses. Issues with the digital board seems more plausible given the circumstances. I definitely don't want to send the main PCB board in if that is not the primary area of concern. I will look at local synth repair shops for review of the digital board and see if, hopefully, there are no significant issues with it. Thanks again!

[Acid Mitch]

I had a similar issue with my Voyager RME. It turned out to be the psu. The psu still wasn’t working correctly after having some parts replaced and all soldering redone so it got completely replaced with a new one. Took Moog repair centre several months to diagnose and fix..

[thereminraul]

Hi!

You solved the problem?

I have the same issue in my Voyager EB.

Thank you!

[stiiiiiiive]

Hey.

I had the experience of rotary switches having "in between contacts" (maybe on a Voyager too, not sure). So as Till said, you can try to turn the octave switch slowly while pressing a key. My guess is that you will here an octave different from the one you're coming from and the one you're going to.

If so, the switch is the culprit and the display is just... displaying it.

[thereminraul]

Yes.

In all octave positions changes they all pass mostly through 32'. The screen shows it and you can hear it.

Also you can put the pot between 16' and 8' and when you play it sound 32' and screen show it.

So in your opinion the problem is with the potentiometer.

Thanks for the information.

[stiiiiiiive]

Well, to be honset, I would not be able to say whether it is a problem or the normal behaviour of such a selector. Maybe someone more experimented than me will know.

[thereminraul]

I have done the test with a Voyager Old School and have the same issue but instead of 32', with 8' sound between the change values.

This is, if you move the switch very very slow changing the octave selector between different values, it sound 8' in the middle positions

Only the selection is clear between 16' to 8' and 8' to 4'.

It is curious that it happens on different units with different values.

[stiiiiiiive]

Indeed. I guess it depends on how the selector is wired.

BTW, you tend to make me think I also saw that on my old Voyager OS. I cannot remember what the "in between" value was though.

[Lumin]

Did you happen to solve your issue? I have cleaned the contacts of my switches and it gets better sometimes, but other times, the problem still persists. I wonder if I need to replace the switches. Anyone know what replacement part number would be? If I recall, these switches were ALPS.

I have done the test with a Voyager Old School and have the same issue but instead of 32', with 8' sound between the change values.

This is, if you move the switch very very slow changing the octave selector between different values, it sound 8' in the middle positions

Only the selection is clear between 16' to 8' and 8' to 4'.

It is curious that it happens on different units with different values.

[molotov]

Hello, I also have this issue on all three Octave selectors. Did anyone come up with a fix?
For cleaning the switches, do I need to take the front panel off to access them? I tried removing the back, but couldn't get to the switches that way...