YAFF from Jack's place: Question??

[Mike Nichting]

OK,
Jack, why is the wiring of the switch different in the picture of the YAFF than the wiring diagram??  The pic I'm looking at is at the bottom of the page where the layout and notes are. I can't get this thing to get any signal in bypass or effect mode.
I have the switch wired like the diagram. I also have the pots grounded to them selves on the 1st lug. Should I not do this?? They were like that from the old Fuzz face I took them out of.

 I guess I am going to make a PCB because I Hate perf~!!!! Less problems for me,plus a PCB looks better.

Thanks for the help~!!!!!!!

Mike N.

Oh BTW: Jack, I love the MOSFET BOOST~!!!  It adds some nice tone to my setup without even using it as a boost. It took me 7 trys due to a bad pot and no meter to figure it out  :oops:

[Mike Nichting]

Oh yeah, are there any direct replacements for the trannies that are suggested in the circuit??

Thanks
Mike N.

[amz-fx]

There are alternate ways to wire a dpdt switch and I used the version on the schematic that grounds the input of the circuit when bypassed so that the high gain circuit is neutered and cannot oscillate.  When I built the prototype I used the other method to test worst case conditions.

The two methods are shown at http://www.muzique.com/schem/dpdt.gif

regards, Jack

[Nasse]

Well, I used some TO-18 cased trannies that I got free from a component shop in Helsinki few years ago. There was a box of them near the cash machine and a text "Help yourself and take few of these, they are free". I managed to take seven. After YAFF was online, I digged my junkbox and measured hfe of those silicon trannies. They were low hfe like suggested in YAFF article. Later I mail ordered some components and those YAFF trannies were easily and cheap available same place so I ordered some of these. I tested it with suggested trannies, but also popped in those freebies 2N2369 which were in the same hfe league, and some T0220 sized medium power transistors (BD139). I used mostly yaff component values, but I had a trimmer for Q2. After this test I am a believer for that theory of right hfe range for ff trannies. I liked the sound better with 100 ohm resitor removed and replaced with wire link, but I mostly used it with fuzz control quite high anyway.

Because the circuit and some germanium leakage test circuit was ready for me to use, I swapped the power supply and caps polarity, I tested it with germaniums (found that two vintage AC128´s I have kept for years like treasure were shit leaky, ordred ten new-made AC128s and four and almost the fifth were usable). Tested some pnp silicons in my junkbox in the right hfe range and sound was just as good as npns, no big difference. Germaniums sounded somewhat different, but good. But not so good that I have not bothered to build one face ready and boxed with them. But it is good to have some challenges. I have one old Japanese transistor radio corpse with promising 12 vintage germanium trannies...

What I want to say a multimeter with hfe measurement possibility is nice one to have if you are tweakin a fuzzface or its derivatives. ANd leakage tester from GEO. Thanks for R.G. for "technology of..." Buy few more trannies than you need, hand pick suitable hfe ones from these by careful measurement, and tweak some component values suitable for your taste and for your transistor individuals and you soon have a good sounding fuzzbox.

[petemoore]

I put the socket in the FF and just use that as a transistor checker...
 I seem to be able to tell the 'good' ones, and can definitely tell the 'bad' ones [for FF at least].
 Not exactly scientific and depends on having good memore and ears and experience listening to differences...but alll in all the FF makes a good FF transistor checker...lol

[Mike Nichting]

Thanks all~!!
Man, I must really have something screwed up somewhere. will double check and also check the switching method. I trust the method used on the schematic but I was just curious and had to ask  

 I have some 2N3904's in there now. I am pissed because I have 3 meters and none of them work so I can't check the bias or anything.

 Thanks again for the help all~!!  I am looking forward to getting this working.

Mike N.

[nightingale]

mike~
i really like that circuit! i have built/played two of them... the first one had the exact trannys that the schemmo calls for... the 2nd one i tried some 2n4401's as suggested by gus... and they killed! it gave the circuit more fuzz... but all of the "fuzz" settintgs were still usefull... the cicrucit has a really really good "spongy" touch sensitive feel... it cleans up so well that i used them full time for a a couple shows...

also, i built one on perf, and the 2nd was the PCB layout from jacks site...
i think it's a sweet fuzz... imo of course...