[sdiy] 566

[Cynthia Webster]

on 1/27/04 10:34 AM, john mahoney at jmahoney at gate.net wrote:

> ----- Original Message -----
> From: "René Schmitz" <uzs159 at uni-bonn.de>
>> 
>> I don't know really why all craze about this chip. ...
> 
> I've been skimming through T.H.'s 566 book again, and the following quote
> suggests that Rene has a good point:
> "Like I say, if ultra precision is your goal, then there are more
> effective ways of designing an exponential VCO for synth work."
> This comment (in the next to last paragraph on page 10) was in light of some
> tracking problems. Basically, the 566 exponential VCO was flat above 9kHz.
> 
> I still say, if you've got the parts, you should at least build a prototype.
> (Otherwise, the parts are *guaranteed* to be useless. ;-)
> 
> One interesting feature of the 566 is that you can get quadrature square
> waves from it -- 4 squares that are 90 degrees out of phase from each other.
> This is really cool for certain modulation uses, although I'd much rather
> have quadrature triangles, ramps and saws.
> --
> john
> 

In his 566 book, Thomas Henry suggests a single resistor solution to the
infamous glitch in the sine converter section's output waveform.
(I wonder if Rex at STS has ever seen this, as it is ~exactly~ the
way Serge Sine waves appear on a scope...)

Cyn