Marbles calibration

I’ve had a Marbles module for a couple of months, now, and used it with just one oscillator, Plaits. The voltages an octave above the central voltage (am I making sense? I hope so!) are flat, and the voltages an octave below are slightly sharp. In both cases, as much as a semitone.

I thought, “You’re doing something wrong,” but even when I set Spread all the way CW, the problem persists. I got another oscillator, recently, and it’s doing the same thing when connected to that, too. So it’s not Plaits’ fault.

This makes for a rather unmusical sequence, which can be demoralising, and I’ve noticed that this happens to other synthesists’ Marbles in one or two YouTube videos, so I’m glad it’s not ineptitude on my part.

What can I do about this, please?

Thank you for any suggestions, good people.

Are you using the module to process external CVs, or to generate random CVs?

The module has no user-accessible output calibration procedure (you would need a rather expensive 5 1/2 digit multimeter to make the necessary measurements anyway!).

You can send it back to me for calibration. support@mutable-instruments.net to know more. I will happily have a look at it, since I can’t really think of a mechanism through which calibration data could erase itself.

I’m using it to generate random CVs. Thank you for your kind offer. I’ll send an email to that address.