Sub 37 Oscillators tuning issue

[wildecat]

Hi everybody,
I'm writing from Italy, new owner of a wonderful Sub 37.
I tried some days ago to tune the secondo osc a minor third over the first oscillator's frequency.
It seems there is no possibility, since the sound is highly distorted, full of overtones as a FM sound.
I can't understand the problem.
The problem occurs with each oscillators wave, at any volume, no matter how open the filter is.
If I tune the second oscillator a fifth, the problem disappear.
Where did I go wrong?

[ChiLam]

Don't suppose you have the "Hard Sync" botton engaged do you?

[wildecat]

No hard sync engaged.

[Amos]

works fine here. can you make a recording of what it sounds like when you start from INIT PRESET, turn up Osc 2 (so both osc1 and osc2 are same level), then turn Osc2 frequency to +3 (adjust by ear for minor third)?