[sdiy] Tau VCO question

[lanterma at ece.gatech.edu]

Thanks to the many folks who responded to our questions about the  
MS-20 VCO!

Another of my students built the Tau VCO (using typical TL08x op amps  
instead of the ones shown).

www.oldcrows.net/~patchell/TAU1010/tau.html

This one oscillates! It gives nice triangle and square waves.

The one curiosity is the voltage swings - the triangle wave is shown  
on yh schematic as going from -5 to 5 volts, but on the scope it goes  
more like -2 volts to a little under 6 volts. And the square wave is  
like -13 to +14 volts.

Of course we could throw on some DC blocking caps at the output bur  
we'd like to understand what is going on better. Anything come to mind?

Thanks for y'alls help, as always! :)

Sent from my iPhone