AC128 paired with AC176 for fuzz?

[jm22]

I've been thinking about using the AC128 for my first fuzz pedal, a fuzz face clone. This transistor model jumped out at me as fairly ubiquitous and still readily available from multiple sources.

In any event, I stumbled onto this ebay listing for an AC128 paired with an AC176. The seller says this pair is for fuzz, but the AC128 is a PNP and the AC176 is an NPN. I thought one must have a pair of PNP (or conversely a pair of NPN) for a fuzz. What am I missing here?

https://www.ebay.ca/itm/FACTORY-MATCHED-PAIR-TUNGSRAM-AC128-K-AC176-K-NOS-GERMANIUM-TRANSISTORS-FUZZ/132994574800?hash=item1ef71829d0:g:l~kAAOSw18Bccr9u

[willienillie]

Factory matched.  Tungsram wasn't thinking about fuzz pedals.

[jm22]

Thanks for the reply. Indeed, Tungsram wasn't thinking about fuzz pedals, but the seller of these NOS transistors certainly is, and he says he's sold 100's over the years. I am trying to understand if one can indeed use one NPN and one PNP in a pedal, say a Fuzz Face, and if so, what advantage might it have, and what changes must be made to the circuit topology to accommodate both an NPN and a PNP.

[idy]

Complimentary pair 2 transistor fuzzes... Roger Mayer Axis... what else? That was silicon.

[PRR]

You CAN use complementary. But for 30 years PNP Ge was much cheaper than NPN Ge. (Conversely, for a decade NPN Si was a dime cheaper than PNP Si.) The fuzz market is CHEAP.

I was looking for Ge complements for a non-fuzz application. But for most of Ge's reign, that was very rare. Maybe one NPN as a power stage driver.

[duck_arse]

buy two of the posted pairs, build two two transistor circuits, one pnp paired, the other npn paired. buy three sets, build two tonebenders ..... can't guarantee the hFE/leak figures, tho. suck 'em and see.

[mac]

There are a number of projects out there for npn-pnp, Si or Ge.

For example Sixties 60s Style Fuzz Box.

Also, Jordan Bosstone, Heathkit TA28, Harmonic Percolator, Arsenio Novo's, can be tweaked to use only Germs. I did this, sounds great, but temperature is a problem with some of this circuits.

What about a small guitar amp?

mac