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Possible bug - can someone try this?

Possible bug - can someone try this?
« on: October 15, 2016, 09:15:48 AM »
Hi all, have to say my ob6 has been pretty great in the bug department - have been using it extensively without running into anything, until now.  Here is the issue I am seeing:

1)  Start from an Init patch (press manual and write at the same time)
2)  Turn Sub-Osc volume all the way up
3)  Turn Osc 1 and Osc 2 volume all the way down
4)  Press the Sync button on VCO1

Now pick a key and press repeatedly.  When I press C2 every 6th note is a full octave lower, pressing other keys the octave shift occurs either more or less frequently, or at the high end of the keyboard not at all.  There is a member on Gearslutz having a similar issue - but for him/her every 6th note is silent.  A member over there with the module could not reproduce the problem, so it may be limited to the keyboard.

Can someone with the keyboard version give this a try and see what yours does? 

Not a deal breaker by any stretch but thought I'd see what others had happen so I when I contact DSI support I can let them know if it is widespread or not.

Thanks in advance!  :)


Re: Possible bug - can someone try this?
« Reply #1 on: October 17, 2016, 01:28:01 PM »
Yes, behavior confirmed exactly as described if set to a positive detuning in VCO2.

Re: Possible bug - can someone try this?
« Reply #2 on: October 17, 2016, 03:38:31 PM »
Hi black953mj. For the record, I'll post the same thing I wrote in response to your support ticket I answered this morning:

What you are hearing is normal and has to do with the sub octave oscillator in conjunction with oscillator sync. It is the known and expected operation of the sub oscillator when sync is enabled. Nothing is physically wrong with the synth in this way.

The sub oscillator is a square wave generated by a flip fop which is driven from the start of oscillator 2's waveshape. When sync is on, oscillator 1's waveshape is retriggered by oscillator 2's frequency. This means that oscillator 2 is retriggered as well, though the frequency of the sub is half that of oscillator 1.

Depending on the oscillators' respective root notes, the sub oscillator may not work consistently from one voice to the next since it is being retriggered at the same time as oscillator 1.
Dave Smith Instruments

Re: Possible bug - can someone try this?
« Reply #3 on: September 25, 2017, 10:32:29 PM »
I did the same test routine on my OB-6 (first OS) and it hasnīt such an issue. Th sub oscillator always sounds stable.
Are there different versions on the market?

Re: Possible bug - can someone try this?
« Reply #4 on: September 26, 2017, 10:38:37 AM »
No, there are not different versions of the hardware. The sub-oscillator behavior with oscillator sync enabled will vary, as I explained above. For the same reason it can differ from voice to voice, it can also differ from unit to unit.
Dave Smith Instruments