Fuzz Face
 

Hello,
I'm planning to build a Fuzz Face according to the first schematic here : Fuzz Central -- Arbiter Fuzz Face

I have multiple questions that may sound dumb, but I'm totally new to DIY :

- There are multiple versions of the AC128 transistor on Banzai Music :
these : Fuzz Face high gain transistor set :: Transistors (matched / selected) :: Semiconductors :: Electronic Parts :: Banzai Music (there's also a selection of diverse version of the AC128 for different gain settings)
or these : AC128 :: Germanium Transistors :: Transistors :: Semiconductors :: Electronic Parts :: Banzai Music

Why such a price difference ? Which is better ?

- I also want to ditch the battery and operate it only on a 9V adapter, I just have to remove the battery connector and put a 9V connector instead, right ?

This is the same circuit used in the two transistor version of the Vox Tone Bender. I made a lot of them in the late 60's and early 70's. The circuit is very sensitive to the transistor used.

I built a board with transistor sockets and just tried lots of parts. Most PNP transistors will work and create some sound. A few will not. Everything that I tried had a different sound. The unit that I kept for myself for all these years has transistors out of an old Sony radio, 2SB383 I think. If you have any PNP germanium transistors, try them. Anything out of a 60's vintage Japanese transistor radio should work. Most silicon transistors work but don't sound so good.

You can experiment with the resistor values in search of the right sound. I wouldn't go beyond 1/2 to 2X the values shown in the diagram.

The AC128 went extinct a long time ago. There are some "new reproduction" parts but they are likely another type that has been relabled AC128. I don't know anything about the parts you linked to since I have never tried them.

Thank you for your answers ! I will try first with the cheap ones and I'll change if the sound doesn't satisfy me.

If you can get them the NKT275s are the best. There's a guy in Germany on ebay called minifux who normally stocks them. Be prepared to pay. :)

"minifux" has nothing to sell right now, but I found these : 4x ASX12D Germanium MATCHED Transistors / NKT275 J FUZZ | eBay

Would they be suited for the job ?

Me too...... (showing my age..)

A socket is a good idea. The sound you are after may not be found without some experimenting.
Silicon transistors will work but, as said, the sound willnot be right. Stick with germanium.

OC71/72 OC81/82, even OC44/45 ( Mullard types) as well as the AC127, AC128 mentioned.

http://www.ebay.co.uk/itm/7-x-oc-71-...item1c21691c1f

Old '60s transistor radios are also a possible source - thrift stores.

Andy.

.

I never got around to finding good germanium transistors for the Fuzz Face.
But you might want to try a Big Muff circuit as well. Uses diodes for clipping and smoother results with Si transistors.

You will need to make sure the transistors are properly biased, there's an elaborate article on geofex.com which describes the FF circuit. It's called "technology of the fuzz face".

Thank you for all your answers ! :)
I'll try the OC71 as well as the others.

@Jarno : that article is really great, thank you

What enclosure will you use?
I think a diecast aluminum enclosure would work well for peddles, and provide some shielding.