[sdiy] matching discreete transistors can be so easy ...

jorgen.bergfors at idg.se jorgen.bergfors at idg.se
Thu Aug 22 08:25:17 CEST 2002


>I've built the well-known Moog test circuit (basically a 100uA current
source), but
>instead of using a transitor test socket, I connected three flexible wires
and built
>a little probe with 3 contacts that can be plugged into the breadboard
parallel
>to a transistor.

This is exactly how I tested the matching of my SMD dual transistors.
I etched a PCB with room for many transistors. Then I soldered them to the
board (remember - surface mounted).
After that, I measurd each pair and wrote the result on the board next to
it.
When all transistors were measured, I took a jeweller's saw and cut out the
best ones from the board, and soldered to 8 pin DIL component carriers.
See http://www.idg.se/personal/bergfors/bergfotron/vco.htm

/Jorgen





More information about the Synth-diy mailing list