Newbie... first and common questions about CA3084 and

[Edward Leckie]

The uA726 is a supermatched pair of pnps with built-in temperature
compensation/control. They're also used in Roland SH-2. The 3094 is near
impossible to get pnp tranny array, similar to the 3086/46 npn array.

btw does anybody know of any decent mods for the SH-2

Ed Sydney, Australia.

____________________Reply Separator____________________
Subject:    Re: Newbie... first and common questions about CA3084 and uA
Author: Andrew Schrock <aschrock at cs.brandeis.edu>
Date:       5/08/98 23:07

Hi Denis! 

On Thu, 6 Aug 1998, Denis Lavaud wrote:
> . Is there any replacement IC for the CA3084 and
> uA726 ICs ?! If not, I would be very interested in
> any datasheet about these ICs or replacement
> solutions ! I read on Rick Jansen's page that he
> would use the MAT02 and MAT03 but I do not have
> any clue of what it is !

The uA726 is super-rare, used in the early moogs for scaling, I believe.
It would cost you at least $75 if you were to actually FIND one, so I
would _highly_ suggest working around it. The MAT02 is a matched
transistor pair, used for temperature-compensated stability. You can just
use a pair of 3096's (or whatever) easily enough. MAT02's are pricey (for 
a single part), around $5 or so. 3084 I'm not sure about.. I know 3046's
are transistor arrays, I think. 

> To indroduce myself, I am an Electronical Engineer
> but in digital IC design and digital signal
> processing. I am supposed to have knowledges in
> analog electronics but as I did not practice this
> last years...
> 
> My project is to build a fully MIDIfied Formant
> using microcontrollers (reading analog pot and
> switches values and of course MIDI controls and
> sending bulk dump and all of this classical stuff)
> and controlling digital potentiometers and analog
> switches. It seems easy to do, maybe easier than
> finding replacement chip to build the analog parts !
> This is still the beginning of the project and I
> plan to start with the 12dB filter and then,
> MIDIfying it. Any comments are welcome !

Wow! Sounds great.. keep us updated, good to have ya here among us without
any degree whatsoever... 

take care,
Andrew

| Andrew Schrock                                                        |
| Network Programmer, Synthesizer and electronic music enthusiast        |
| aschrock at cs.brandeis.edu                                                |