microbrute pitch cv output: cv offset issue [partial fix]

[bartleby]

i love to use the microbrute so sequence my modular synth. that's why i have two microbrutes. but both of them have the same nasty problem with their pitch cv outputs: both have a negative offset, one of -20mv, the other one of -30mv. so when playing octaves, instead of

0v ... 1v ... 2v ... 3v ... etc

i get

0v ... 0.97v ... 1.97v ... 2.97v ...

this is really annoying. when sequencing an analog vco, a workaround is to avoid the brute's lowes prime interval and tune the vco a little up. but with some digital oscillators, like my beloved mutable instruments tides, where the 'coarse tune' knob is already quantized for half tones and the 'fine tune' knob is normalled as an attenuator for the fm input, that is not an option. so i really need a solution for this.

@arturia:
is there some way of recalibrating the cv output?
or should i send in my microbrutes?

@other brute owners:
do yours have the same issue?
have you found some kind of solution?

any help would be greatly appreciated.

[bartleby]

as usual, no help whatsoever from arturia - either here or via their support. i think the way arturia treat their customers is a discrace.

by contrast, arturia's german distributor tomeso have been super helpful. they checked back with some arturia tech people and found that the pitch cv offset can be set by an internal trimpot, t1. that way, i was able to all but fix this issue at least on one of my two microbrutes (the other one seems to have an additional cv scaling issue which i haven't found a fix for yet). using t1, i was able to adjust the pitch cv output so that all notes except for the lowest c now have a correct v/oct output.

so instead of:

0v ... 0.98v ... 1.98v ...

i now get:

0.02v ... 1v ... 2v ...

not perfect, but good enough for me.

if you have the same issue and want to try this fix, it's really easy to do. (if you brute is still under warranty, i would advise against opening it without first checking back with their support or at least your local distributor, though) all you have to do is remove the 12 screws holding the bottom plate in place, gently lift up the bottom plate (watch out for the ribbon cable conneckting the kb), find t1 and adjust it for correct voltage for the second or third c (1v or 2v respectivley).

many thanks to frank of tomeso for researching this for me - and no thanks at all to arturia's useles support.

[protman]

I found this information in another thread.

On rear board:
T1 Pitch CV gain
T2 pitch CV offset
T3 LFO CV offset
T5 Saw offset (PW range , and triangle shape depend on this one too)
T7 Saw amplitude (Sub/5th range, and triangle shape depend on this one too)
T6 VCO offset
T8 VCO slope

On top Board
T3 Filter cutoff range
T2 filter resonance range

http://forum.arturia.com/index.php?topic=14446.msg39669#msg39669

I have a Make Noise 0-Coast on the way and heard about the offset issue.

It says here T1 is the CV gain and T2 is the CV offset.

Is T1 still the relevant one to adjust?

[LarryMal]

Is this Anvarol review still the relevant one to adjust?

I think so protman, can anyone confirm?

[mebitek]

I use the t1 screw to let the microbrute send correct 1cv/oct