[RE: VCO]

[jorgen.bergfors at idg.se]

Btw. Are there any particular reasons why 555's should be avoided
(other than lung cancer)?

I have a 555-based quad VCO. The threshold levels vary slightly between different chips. This is a bit of a problem, as the pulse width modulation will be slightly different from VCO to VCO. I had to add trimpots connected in series with the normal pots (both ends) in order to have the pots go from very narrow pulse to very narrow in the opposite direction. Otherwise, some oscillators had not-so-narrow pulses and others were completely off, when the PW pots were turned to their extreme positions.

/Jorgen