[sdiy] CA3046 vs. CA3083 and matched pair madness

[Romeo Fahl]

Here's a schematic and instructions from an old Moog service manual.  
There was a mistake in the original document, but this one has been  
corrected.

http://www.oldcrows.net/~oldcrow/synth/misc/matching.gif

And if you're really crafty, there's even a PCB layout that you can  
use to roll your own matcher:

http://www.oldcrows.net/~oldcrow/synth/misc/mtchrbot.eps

http://www.oldcrows.net/~oldcrow/synth/misc/mtchrslk.eps

I've built this one and use it periodically, whenever the need arises  
to match my own transistors. Definitely use an 8 pin DIP socket for  
the transistors to be matched.

Also, FWIW, don't handle the transistors to be matched with anything  
that will change their temperatures immediately prior to matching  
them (like your fingers). This can throw off the results. I typically  
use a pair of needle nose pliers to load them into the socket.

Romeo


On Nov 14, 2006, at 12:39 AM, Matthias.Herrmann at jeppesen.com wrote:

> owner-synth-diy at dropmix.xs4all.nl wrote on 11/14/2006 09:29:42 AM:
>>
>> Go the Patchell way and use a pair of 2n3906. I bought a bag of  
>> 100 and
> set
>> down to match them for his vocal filter. I could have used them  
>> straight
>> from the bag they were that close.
>>
>> Ken
>
> how do i match them? would i need a specific circuitry?
>
> matthias
>