# Pitch issue when turning mixer knob **URL:** \ **Category:** Super 6\ **Tags:** issue\ **Created:** [19 September 2026 14:08 UTC](https://forum.udo-audio.com/t/pitch-issue-when-turning-mixer-knob/4030 "2026-09-19T14:08:04Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![petter](https://avatars.discourse-cdn.com/v4/letter/p/dbc845/32.png) [@petter](https://forum.udo-audio.com/u/petter)\ **Post date:** [19 September 2026 14:08 UTC](https://forum.udo-audio.com/t/pitch-issue-when-turning-mixer-knob/4030/1 "2026-09-19T14:08:04Z")
Hi! I have a strange problem that started occurring recently out of nothing. When turning the mixer knob the pitch changes; a semitone up when turned to the left (DDS1) and a semitone down when turned to the right (DDS2). This happens on every patch, including the init-patch (shit+manual). Does anybody know how to fix this? 😵‍💫 I have the xos\_v1.6 firmware on my UDO. Best regards Petter ---
**Author:** ![HelenMarsh](https://avatars.discourse-cdn.com/v4/letter/h/a183cd/32.png) [@HelenMarsh](https://forum.udo-audio.com/u/HelenMarsh)\ **Post date:** [1 October 2026 07:27 UTC](https://forum.udo-audio.com/t/pitch-issue-when-turning-mixer-knob/4030/2 "2026-10-01T07:27:05Z")
Because the shift follows the mixer control and is exactly about a semitone in opposite directions (DDS1 versus DDS2), I’d first separate a control-voltage/mixer-routing problem from oscillator tuning. With the init patch, tune one oscillator to a known A=440 reference and monitor it alone; move the mixer knob slowly. If that isolated VCO’s pitch changes, check the mixer’s VC routing/normalled CV and any modulation assignment (including MIDI pitch-bend), rather than the waveform level. If the isolated VCOs stay fixed but the combined sound shifts, look for a digital detune/voice setting or calibration issue. Also unplug MIDI/USB and repeat with pitch-bend centred: a stuck or mis-scaled MIDI pitch-bend can move pitch, although the opposite DDS1/DDS2 behaviour points more strongly to routing. Verify against the known A=440/patch-tune reference before recalibrating or changing firmware. For a quick refresher on hearing intervals and tuning checks, [listening and frequency reference](https://kyma369.com/frequencies).