Sawtooth oddities

[Agschool]

Hello all

I've got this weird problem with my semi-modular synth. If I use two slightly detuned
VCOs on sawtooth, then the final audio output appears to be very unstable. For about
a second or so, the sound is the usual rich phasing type sound, then suddenly the sound 
changes as though one osc. has sync'd with the other. In fact, the output sounds rather
nasty. When using triangle or square outputs, or any combination, this sync'ing feeling
just does not happen.

If I modulate one of the VCOs with a LFO then the problem never occurs. Probably because
the oscilators need to have a fixed frequency to lock.

The VCOs are CEM types and only share the same psu. The outputs are totally isolated from
one another until summed in the output mixer.

Any ideas?

TTFN

Tony Allgood
-- 
Appleby Grammar School, Appleby, Cumbria
Phone 017683 51580
Email TJA at agschool.zynet.co.uk