[sdiy] 566

[Cynthia Webster]

Hi Gang!

Thomas Henry still has the 566 VCO chips at $6.00 each.

Warning: These are really quirky chips hat need special support
circuitry to be useful as VCOs and Henry's little book on
using them in circuits is highly recommended!

(Great reading too! I find his style to be the most conversational
form of technical writing I've seen.)

http://www.midwest-analog.com/catparts.html

Best to all!

Cynthia



on 1/27/04 7:30 AM, Scott Gravenhorst at music.maker at gte.net wrote:

> jbv <jbv.silences at club-internet.fr> wrote:
>>> Do you mean the 556 (dual timer)?  566 is anything but cheap
>>> now that it's transmuted into an isotope of unobtainium.
>> 
>> I really mean the 566...
>> A few months ago I got 40 pcs on ebay for less than $30...
>> 
> 
> Ok, "cheap" for you then.  Well, sure, it would work that way.
> But if you want each one to track an expo CV, you need expo
> converters for each one (or lots of good sample and hold
> circuits with one expo converter and the driving logic).
> 
> If you don't care about voltage control, i.e., just a bank of
> oscillators each with a frequency pot, then the 556 dual timer
> actually makes more sense, depending on exactly what the
> intended use is.  If it were me, I would not use the rare 566
> for non VC applications.  Also, if you decide to use the 556
> (dual timer), there may be problems with soft synch, especially
> between oscillators on the same chip.  There may be a CMOS
> version of the 556 which would be somewhat better.  If not,
> there's always the 7555.
> 
> I gave up on finding the 566, it's a single chip tri/square
> VCO, which is something that can be done fairly easily in other
> ways.  LM13600/LM13700 and I assume other dual OTAs as well can
> also be a one chip solution.
>