uA726 replacement, (the comedy of errors)

[jorgen.bergfors at idg.se]

>>Analog oscillators exhibit "phase wobbles" in the +/- 1 cent range and
>>probably account for that "warmer" sound (not the chip heater).

>I am experimenting with an integrator/comparator saw VCO ("ASM1 style")
>that does this.  Unfortunately it also has an additional "wobble" of about
>+/- 5 cents with a period of about 15 seconds.  I am stumped as to why this
>is happening.  I've tried to use all the proper components: good power
>supply, .01uf caps on the board from supplies to ground, MAT02 pair & C-2AQ
>tempco heat-sink-gunked together, 50 ppm metal film resistors, multi-turn
>trimmers.  Has anyone experienced this kind of behavior before?

When you mention this, I remember that there was some sort of cyclic variation when I made my VCO masurements (see http://www.idg.se/personal/bergfors/bergfotron/vco.htm).
But in my case I think the period was more like a minute. I'm not sure if it was 5 cents either. In any case I don think it was large enough to be a real problem. It just made precision measurements a little trickier.

/Jorgen