BE fuzz face SZ vero v1

BE: Fuzz Face, SZ-3 (Sziklai pair)

by

Just one of my little side projects – it’s a pretty hot day here, so not one for playing with germanium transistors in a big black box with a tin roof (also known as my garage / workshop).  The leakage goes nuts, and they sound like balls…  

While playing around with a bunch of old low-gain silicon transistors with moderate success, I remembered the Sziklai pair.   A minute later, and it was silicon fuzz heaven, so I had to come up with a layout to build one, hence the post.

BALMORAL ELECTRIC, SZ-3 FUZZ FACE

There are a few random values used that obviously aren’t for everyone.  They just happen to be what’s on my breadboard.   But hey, the post isn’t for everyone; it’s mainly for me to come back to later.

Transistor types are not listed, in part cause I can’t recall what is on the breadboard.  They are all very low gain silicon transistors – I think about 50hfe or thereabouts.  I’ll update the post with details later.
The Szik collector measured about 4.3v on a 9v supply.

SZIKLAI PAIR

What’s a Sziklai pair?  It’s a bit like a Darlington pair, but it uses an NPN and PNP transistor to create a single high-gain transistor out of the two low-gain devices.   They tend to act more like a single transistor than a Darlington does, which makes it handy for a fuzz face.

Before you get too excited, this works best with silicon; it’s not a magic bullet for not so great germanium transistors, as leakage and noise are also multiplied.  

FURTHER READING

Leave a Comment