My Brute's pitch scaling gets slightly sharper in highest octave

[dexfx69]

Loving the Brute much. Kudos to Arturia! 

When I select the Octave button's highest setting (+2 octaves), and play the highest octave on the Brute's keyboard, the pitch is slightly sharp. Not a big deal but is this normal?

[elthorno]

Hi,

I have noticed the same thing- just the top octave for me. I've looked at it on a guitar tuner and it does drift out by quite a few cents. Generally I can usually correct it using the fine tune, sometimes I leave it because it can sound kind of cool. I would also be interested to know if there's a fix using a trim pot.

I'm already on my second Minibrute. The first one I got had a glitchy pitch bend wheel, which produced random pitches just above the centre. I tried updating the firmware, nothing happened, so I took it back.

Sorry for going slightly off topic, but the tuning thing did make me think, have I had two dodgy units in a row, or is the tuning a result of the VCO design?

[Bruno@arturia]

The actual design of the VCO is indeed sharp when you reach the last octave available with the built-in keyboard, in octave +2 mode.
Usually a VCO turns flat, this one is sharp because it has been overcompensated during the design.
If your VCO is fine over every octave except the last one, you won't get it much better.
But if tuning is turning more and more sharp over several octaves, you can use a trimmer to correct it, but it won't help for the last octave.
I mean you can trim the VCO slope but no trimmer is available to set linearity of last octave.

The only way to correct it is to change the value of a SMD resistor.

[dexfx69]

Thanks for letting us know Bruno. Really great keyboard, nothing else like it, and true VCO sound. Now that Dave Smith is moving away from analog and more into digital with his Prophet 12 VA, you guys are taking over the analog scene (along with Korg).

I hope you sell tons and are able to carry on making more new analogs, esp POLY!

[elthorno]

Yes, thanks for the reply Bruno. Put my fears to rest -this is my first VCO-based synth, so I'm getting used to the little quirks.

Overall I think you've nailed it with this synth. You can't beat having all the controls to hand.