Very unstable tuning / intermittent problem

[runew]

Hi

My Minitaur is behaving weird. Most of the time it stays in tune. However sometimes it detunes quite a bit. Most of the times it tunes approximately a whole note flat. It is the same for both oscillators - so it's in relative tune... When I restart, it's back in tune for a short while.
At first I thought it was because of temperature changes (as it first appeared at a concert).
But at a rehearsal tonight (in a room with aircon) it happened again. The first 3-4 hours it stayed perfectly in tune. Suddenly it started being a whole note flat. I tried restarting a few times, but after about a minute each time it got out of tune again... While being out of tune I then performed a calibration. This, however, resulted in it tuning exactly half a note flat (half a note higher than before)! The "fine tune" being in center position of course.
I run the latest firmware (2.0.21). After updating I do a factory restore and a pitch CV reset. It has happened on several firmware versions.

Are the oscillators really this sensitive - even to the slightest temperature changes? I just find it weird that the oscillators stay in relative tune...
Is it possible that this is a software bug or do I maybe have a faulty unit?

Thanks in advance,
Rune,
Denmark

[Amos]

No that doesn't sound temperature-related, and the oscillators aren't that temperature-sensitive anyway. It sounds like a fluctuation in either the fine-tune (which is completely analog, no firmware control of fine tune) or the external pitch CV (which is scanned and summed with the other pitch variables in firmware) - so, I'd say it's not purely a firmware bug but is either an analog-only problem, or an interaction between the hardware and the software...

[Karsten42]

Hi,
I'm currently testing my second unit of a minitaur. The first one issued the bootloader problem. Now I've got a new problem. When filter envelope sustain is all down the unit is in perfect tune with my other gear. When increasing it there's a sudden transistion just before the second marking when boths oscillators detune by approx. +38 cents. When increasing filter envelope sustain even more this detune keeps constant. This effect is independent of filter eg amount.

What to do?

Kind Regards,
Karsten

[Niklas]

Hi there,

I have the exact same problem.

I just got my Minitaur today. At first it had a problem with the the VCO 2 which was tuned a little to high. After calibrating this was solved but then the filter envelope sustain turned out to mess around exactly like you described it.

Did you find a solution?

Thanks,
Niklas

[Amos]

That is a very unusual problem. I would suggest you try updating to the newest firmware.
This version has not been officially released yet but it will be very soon; perhaps give it a try:

http://www.moogconnect.net/downloads/mi ... v2_1_0.zip

update instructions:
http://www.moogconnect.net/downloads/mi ... README.txt

let me know if this helps.

[Niklas]

I just updated the former firmware (v2_0_26) and did a calibration - now it works totally fine!
Hopefully it'll stay like that.

So probably no need for installing the new firmware. Are there any big changes or is is just more stable?

Thanks Amos !!!