Out of tune on higher octaves

[bolovintsev]

After calibrating my MicroBrute using 2 screws on the back panel (I did it same way as for MiniBrute) I got good results.
At the same time on last 2 octaves pitch is going sharp on all notes (the higher the note is the more it's out of tune).
I read that MiniBrute has the same problem due to it's construction.
Is it normal behaviour for MicroBrute?

[Bruno@arturia]

by how much cents?

[bolovintsev]

I'm using tuner that shows me base frequency (not cents).
This tuner works great with synths (NordLead is perfectly in tune there).
For C6 it shows 1050.5Hz (should be 1046.5) and for C7 (last possible C on a keyboard) it shows 2108 (show be 2093).

[Bruno@arturia]

so it's around 5 cents on C6 and 11 on C7. It's not crazy for a VCO.
Are you perfectly in tune in low octaves? you can maybe very slightly turn the slope trimmer. It will make low freq a bit sharper, and High freq a bit flatter.
Anyway, you can get a little bit better than 11cents on C7 but it will never be perfect on the whole range.


By the way, I think the NordLead is a Virtual Analog, not a real analog. If so, it's of course in perfect tune everywhere, but that's a different technology.

[bolovintsev]

Got it.
I have pretty good results in low octaves.
I mentioned NordLead just to show that my tuner works well with synths and I can trust it's results.

[an3]

can u please explain to me (or refer to media sources) how the tuning of the two screws worx. my micro is far out of tune.
regards

[snowcrash]

Don't forget to give it at least 30-45minutes of warmup time before tuning.

[Lars]

got my microbrute yesterday.

how can i figure out that he is "in tune" ? is there a tool to find it out ?

thx

[dalasv]

Yes, a tuner.

[an3]

yes.. yes no novice here.. warm up a tuner n all.. but How to use the 2 screws on the back ?!

[Bruno@arturia]

the one next to fine tune is the offset, the other one is the slope.

[an3]

great ! ialtough i coudl gues howit applies a bit mor info would be great. direction relative to what.. maybye a drawing of the relation between the two parameters

tnx

[Bruno@arturia]

you can follow the enclosed process. It's been written for minibrute, but it the same for the micro. As I said, the trimmer next to fine tune is the offset, the other one is the slope.
This technote describes one way to calibrate a VCO. you can find another way on the great Yusynth site:
http://yusynth.net/Modular/index_en.html in VCO page.

But take warning, if you're not familiar with this kind of operation, you could very easily have a result worst that what you currently have. It could difficult to have a better result that what the factory does, and you can't go back to factory settings. So use it at your own risks.

[BichoVergara]

Hello everyone ... I think I can explain in simple words how the rear screws works.
I've been trying to tune my microBrute for the past few days, and it was a headache for me to understand how the rear screws works ... after trial and error I have come to the following conclusions:
First of all (as Bruno@arturia said) "the one next to fine tune the offset is, the other one is the slope" ... for me that means nothing, but it serves as a reference.
Sure... warm up for 30-45 minutes and have at hand a tuner.
Take as a reference C3, which is the center C of the central octave (octave 0).
The first screw (Offset) serves to place the knob "fine tune" centered (something like a "gross tune")
The second screw (Slope) serves to zoom in or out C2 from C4.
and there you go!!
The truth is that I am not an expert in analog, and I'm far from being a keyboardist... more like a guy who likes to make noise
If someone wants to correct me, please go ahead!!!.