Could I have fried my AC128s ?

[scuzzphut]

I'll tell you DIYSB, I'm having terrible trouble with my f*zz f*ctory clone.

I bought a pair of AC-128s and after 2 days of fault finding I realised that I had the emitter and collecter mixed up.  Reversed them and I'm getting some noise out of the thing but it's still not right.

Having checked everything else, I'm reaching the conclusion that it might be the transistors themselves - could I have fried them by having them upside down and powered up for a while

[tubelectron]

It is possible, but not a certainity. The best way to know it would be to measure Hfe and Iceo on these AC128. Have a look to R.G. Keen's article "the technology of the FuzzFace" : there's is some clues to do it easily.

In the FuzzFactory, some transistors work better than others, and the original hand-painted FF that I had in hands didn't use AC128, but transistors of a different shape that were re-labelled "ZVEX 609", so I don't know what they are really. These Ge transistor sounded always a bit better than any of the NOS US or EC transistors I tested, I mean that I approached the sonic results very close, but not equal, particularly in the fuzz decay, which was not as smooth.

A+!

[scuzzphut]

Thanks for your help Bruno - I'll take a look at that article and take the measurements.   

[Pyr0]

^^^ @ Bruno.
I was repairing an original Fuzz Factory a few weeks ago, and I noticed the same transistors labeled ZVEX 609, they were in a T05 can package.
I wonder what they really are ?

[LucifersTrip]

in a million breadboardings I've never blown a transistor by putting it in the wrong way...remember, if you do that, you'll usually just get a much smaller hfe and it works poorly.

if you've blown it, I think it's most likely from overheating during soldering or a short you may have caused accidentally.

[tubelectron]

^^^ @ Bruno.
I was repairing an original Fuzz Factory a few weeks ago, and I noticed the same transistors labeled ZVEX 609, they were in a T05 can package.
I wonder what they really are ?

Ah, yes : it's a TO-5 package - I forgot it when I wrote my post, sorry & thanks, Pyr0. These have the same size as a 2N1711. But I really don't know what ZVEX609 transistor are, except that they are Ge, and - maybe, but unsure, only a free supposition - a re-labelling of a 2N609, which is a Ge PNP transistor in TO-5 case also 

in a million breadboardings I've never blown a transistor by putting it in the wrong way...remember, if you do that, you'll usually just get a much smaller hfe and it works poorly.

if you've blown it, I think it's most likely from overheating during soldering or a short you may have caused accidentally.

You're right, LuciferTrips. It would be quite surprising, but...

A+