[sdiy] MAT04 / MAT14 and AN-299 Re: Elektor Formant Re: Test / Sequencer / Arduino

[Rick Jansen]

On 25/03/2015 15:27, Florian Anwander wrote:
> Hello Rick
>
> I've built my Formant 1979. So I hope back then I wasn't not yet in the
> foolish-range ;)

Oh yes, you were. But it suits you well :-)

> In regard of the uA726: I bought 10 from the seller utsource in China /
> Hongkong for ~$3 each,  and they were not fakes. I think utsource still
> offers them .

Ah, are they old stock, or produced new?

I stil have some uA726 spares too, I wanted to be safe :-)

Has anyone ever tried a MAT04 (two matched pairs on a chip) as the exp generator in a VCO? 
You could easily use two of the transistors as the matched pair, and use the other two as 
sensor and heater, as in AN-299 (Linear Technology Aplication note 299). The clamp circuit 
could be an external transistor.

Oh, MAT04 is now obsolete, but just succeeded by MAT14 last year!
<http://www.analog.com/en/products/linear-products/matched-transistors/mat14.html>
Time flies..

I see the author of AN-299 has left us, too
<http://web.mit.edu/klund/www/jw/jw-music.html>
and that it mentions a certain Barry Klein book ;-) App note 14 mentioned can be found in: 
<http://cds.linear.com/docs/en/application-note/an14f.pdf>

rick