MK2
How about some MK2 tweaks. I've been buying way to many germanium transistors of ebay in hopes of creating myself some killer fuzz pedals. I have a BYOC MK2 that I am using for the listening -*test*-('")s and I am finding that a little leaky can sound much more interesting at times. I also found that swapping Q2 100hfE or so and Q3 125hfE had really interesting results. I prefer a 47K collector for Q2 and upping the 470ohm to 1K added some output but then I had to up Q3's trimmer quite a bit to reach 4.5V on Q3 - I found that as the voltage got even higher I liked it even more. I've got a few that I am building up on perfboard D*A*M style and I'm going to stay fairly stock and try and find just the right trannys and solder em in - no sockets, led's, or pulldown resistors on these. Any thoughts?

How do you -*test*-('") for HFE of trannies. I find beavis audio always has some interesting fuzz mods, but these are for the fuzz face rather than MKII. http://www.beavisaudio.com/Projects/FuzzLab/byocfuzzmods.htm

I use this method http://www.geofex.com/Article_Folders/ffselect.htm I really want to get one of these http://cgi.www.peakelec.co.uk/acatalog/jz_dca55.html but they are not cheap :)

I really want to get one of these http://cgi.www.peakelec.co.uk/acatalog/jz_dca55.html thank you for posting that!!! i need to get one of those. calculating gain and leakage in germaniums is such a huge pain in the ass and time waster.

The reading on Q3's collector will depend on the hfe levels of the transistors within the circuit. please expound. I was told the collector should be biased to read 4.5V

Not the in a MKII. On vintage units it varies from around -7.6V - -8.9V. Even seen em with 9.1V! I take measurements with Zinc Carbon batteries which are around 9.6 Volts when fresh. The original batteries used in the MKII's and its variants were PP4's (Eveready 226) which also read high at around the 9.6V level. Hfe levels are usually higher also. For example my '67 Supa Fuzz measurements... Q1 - 174 Q2 - 208 Q3 - 194

wow thats really cool! I've been trying to do it kinda like a fuzz face with a 65 or so in the first and 80 in the second and 120 in the third. When I reversed 2 and 3 the other day I really liked the results. I will play with some higher gains. I was also blown away the other day when I had a buddy over and he played guitar while I swapped Q1. It seemed that leakage played nearly as big a role as gain with the trannys. Are you still planning on posting some MKII schematics? Also would you mind sharing what you are doing with the trimmer on Q2?

Is that reading taken whilst playing a chord through the pedal or just while the pedal is 'dormant' if you know what i mean? I found having a higher voltage reading meant it cleaned up a little better when lowering the guitar volume, but i'm still experimenting. Also for fellow tinkerers, there's a good site for fuzz schematics etc including an old gooped MKI circuit photo here: http://fuzzcentral.ssguitar.com/index.php

Shit - that is a good site. I'm late to the party...

Q2 IS the transistor
Also think about this... A while back I did alot of -*test*-('")ing with this circuit. I found over and over again that Q2 made all of the difference- especially when it came to noise. I'm talking the bad white-type noise. I could take 2 transistors that -*test*-('")ed almost identical and when the quieter one was in Q2 it made for a much quieter pedal.