Metalizer transistor matching.

reve · Joined: Feb 23, 2008 Posts: 149 Location: USA

Hi electro-pals.

So I was thinking about hacking together a polyphonic version of Yves' Metalizer circuit. To make this worthwhile, I'd really have to have the SMT machines build the individual subcircuits for me.

The Metalizer requires two pairs of matched transistors, but I'm not clear how matched they need to be. I guess my primary question is:

Q: Assuming modern SMD parts, would two transistors adjacent / near each other on the same roll be, like, matched enough for this purpose? It ain't 1960 anymore, after all.

(I know the BCM8x7DS series of matched transistors exists, but LCSC doesn't stock the NPN versions. I'd rather include a couple extra through hole parts than hand-solder those little bastards on cheap boards...)

If anyone has any ideas... I'd greatly apprecaite it. Smile

Thanks!
rm

gabbagabi · Posted: Thu Mar 31, 2022 11:18 am Post subject:

ive never saw mentioned that the transistors have to be matched

reve · Joined: Feb 23, 2008 Posts: 149 Location: USA

gabbagabi · Posted: Thu Mar 31, 2022 9:55 pm Post subject:

nice! me and my big mouth Shocked

i had this in mind:
https://www.elby-designs.com/webtek/cgs/cgs52/cgs52_folder.html