Fuzz Face output capacitor value discrepancy

[ErikMiller]

Having built a few NPN silicon FF's, I decided to use a couple of the old germanium transistors I found in my parts bin and make a Ge PNP.

I've got the thing all soldered up, but just now noticed that the schematic I'm working from shows the last cap before the volume pot as being 0.1uF.

My NPN sili's used 0.01uF. I got that schematic from Philip Bryant's Fuzz Central site.

This time I happened to be working from a J.D. Sleep schematic I found at General Guitar Gadgets.

The schematics at General Guitar all call that cap 0.1uF, whereas the schematics at Fuzz Central and Technology of the Fuzz Face call it 0.01uF.

This seems like a pretty big discrepancy. Anyone know which one the originals were? I like the sound just fine with 0.01uF in there, but now I wonder....

[jsleep]

You may or may not hear any difference in output cap values, depending on where the output is going (type of amp, etc).  

As far as I can tell 0.1uF is the original germanium transistor Fuzz Face output cap value.  This is also the value used in the reissues that I've seen.

JD

[Rob Strand]

I spent quite some time stuffing around with this one.  The majority of units appear to use a 10nF cap on the output.  Ammscray said he has seen the odd  few with 47nF (but never 100nF).  The Fulltone units have the 100nF.

[phillip]

All the original Fuzz Faces that I've handled use the flat yellow polyester film capacitor marked 0.01µF.  Take a look at the picture of an original Dallas Arbiter silicon Fuzz Face circuit board below:



The value of the output capacitor is 0.01µF with a voltage rating of 250V.  I tend to like the 0.01µF, but the 0.047µF is also nice without making the tone too muddy.  I also like to replace the 500K "volume" pot with a 100K audio.

Hope this helps!

Phillip

[phillip]

And here's a picture of the circuit board of an original Germanium Fuzz Face that I just dug up.  This is one of the NKT275 units:

 

Phillip

[R.G.]

There ain't no magic there.  Even getting one of the original caps themselves won't make the sound magic.

Go get yourself a 0.001, 0.01, a 0.022, a 0.047, and 0.1.  Now sub them in and listen for your own personal ears to tell you what is best.

It will either matter to your ears or it won't.  If it does, you know which one to use, regardless of what any schematic may say is right. If it doesn't, the schemos don't matter either.

Trust your ears.

R.G.

[ErikMiller]

Thanks, Phillip, for clearing that up. 0.01uf it is (was).

Yes, R.G., the "right" value is the one that sounds best to me, however, when building these things, I like to start with what the designer specified, then experiment from there. My formerly stock Cry Baby GCB-95 is now on its 3rd set of transistors, its 4th "Q" resistor, its 2nd inductor....I'm very much into swapping parts in and out to see what sounds best.

My Fuzz Faces use 100K volume pots because I prefer the sound, but I definitely started with the 500K.

I'm going to make one of those FF's with sockets so that I can experiment with different transistors.

[Dai H.]

A while back, either here or at Ampage, someone reported an apparently stock 22nF (0.022uF) in a Silicon FF (IIRC). Also, the original pots may have been way off in some (many?) units, judging from buying, measuring old new pots, and hearing reports of far off value pots in old Marshalls, for example (about the same era--late 60s or so). Today's pots (and parts in general) seem to have much better tolerances. Also, FWIW, I tried a big value tantalum (100uF) for the 20uF, with potentially interesting results (more tighter, modern sounding according to my recollection). I'd be interested in someone else's impressions (if they try it).

Dai

[bwanasonic]

I'd planned on fooling with output caps in my homemade Ge FF eventually, but after reading this thread I decided now was the time! I had the GGG spec'd 0.1 in there and was quite happy with the tone. I just soldered in a socket and compared the *original* 0.1 metal film, a 0.01 metal film, and a .01 ceramic. I went with the .01 metal film. The 0.1 was *woolier*, which I kind of liked for some things, but overall the lower cap value seemed more versatile. The ceramic's "grain" didn't seem to work well here ( although I love a 0.0056 ceramic input cap in my Rangemaster clone). It's funny- until I recently started building my own effects, I thought all this talk about being able to hear the difference between different cap types was a bunch of audiophool hooey!  :idea:

Kerry M

[Rob Strand]

difference between different cap types was a bunch of audiophool hooey

Ceramics are about as extreme as you get for cap audibility, yes you can hear the difference.  Audiophiles would never use ceramics, when you get into to realm of film caps it does become a lot of "hooey" .

[gez]

I can't remember the details, but Electronics World did a never ending series of articles on cap testing and small value ceramics came out of it pretty well if I recall, having quite low distortion  (I think that was the case - I kept nodding off as it was a a bit of a dry read).

[Dai H.]

Note that there are different types of ceramics though. The temp. compensating (NPO, etc.) are supposedly better sounding for some situations/ears.

[Rob Strand]

> small value ceramics

Yes that's true, small ones are OK.  The smaller ceramics use materials which have lower dielectric constants and this tends to result in better linearity.  You won't find many larger ceramics made with the same material as the smaller ones- they would be too big.   The dielectric material is the main cause of non-linearity.

[analogmike]

It's funny- until I recently started building my own effects, I thought all this talk about being able to hear the difference between different cap types was a bunch of audiophool hooey!  :idea:

Kerry M

It is all Hooey according to Jack at AMZ, check out his website

:wink:

[Dai H.]

This is supposed to be a 70s vintage FF (looks like BC109s) which appears to have a 473 (0.047uF) tropical fish metal polyester cap stock:

http://page5.auctions.yahoo.co.jp/jp/auction/e31290859


Dai