unnamed fuzz

[Maroslav]

Hi guys! I'm from Poland and I'm new Here
Last weekend I've decided to build X FUZZ.
After hours of tweaking I ended up with this:

Can someone verify this layout?

[stonerbox]

THE WIZARD! 

The fuzz sounds great man, gonna have to build one. Cheers!

[Puguglybonehead]

Nice fuzz! Will have to try this one myself. Where did you find the AC121s?

[Cozybuilder]

Your Vero layout looks fine. I built this one awhile ago, its a good one.

[Maroslav]

Thanks, man, I really appreciate it.
I found AC121's in my Dad's electronics stuff
Q1 hfe is 325 and leakage is 0,4mA
Q2 hfe is 300 and leakage is 0,5mA
I'm confused about how this sounds that good with that leakage 

[DDD]

Impressive sound!
Well Maroslav, is it possible to make one more soundclip with Si trannies just instead of both Ge ones? (No any more changes)
There's a solderless bbd on the picture, so it seems not to take too much time (?)

[monksanto]

Are those AC121s the same as Russian MP20As such as on ebay? - http://www.ebay.com.au/itm/20x-MP20A-AC121-Vintage-Russian-Germanium-PNP-transistor-/191037487091

[Maroslav]

I can try MPSA14 if you want.
MP20A should work, but my AC121's are from VII Hfe group, so they should have Hfe from 125 to 250

[Gus]

Reminds me of the MinuteMan fuzz posted in 2011

[DDD]

Hi Maroslav,
MPSA14 are Darlingtons, so they are not "typical" here.
Something like BC556...560 are to be the best choice for that purpose.
Thank you in advance.
*** It's a good chance to compare Ge and Si features using the SAME SOUND CHAIN. 

[deadastronaut]

 

[Maroslav]

I'll try BC560's tomorrow
Signal chain is just guitar, fuzz and amp.

EDIT:
Here's BC560's.
Brighter, little less gain and more choky on chords

 

[DDD]

Thank you Maroslav for the BC560's test.
As far as I can hear, your Si version sounds very close to the original version of XFuzz.
Ge version seems to be much more interesting.
Maybe some filtering (HF cut) may improve the Si version, but I'm not sure that the Si version can be very close to the Ge one. It's a pity.

[Maroslav]

Board is already soldered 

[Elijah-Baley]

Good job!

Thanks, man, I really appreciate it.
I found AC121's in my Dad's electronics stuff
Q1 hfe is 325 and leakage is 0,4mA
Q2 hfe is 300 and leakage is 0,5mA
I'm confused about how this sounds that good with that leakage 

I found AC121 on musikding, but the hfe is very low compared to your transistors. Are those much differents?

By the way... Is that a Crate amp?

[Maroslav]

Yes, It's Crate FW15R 
I can't say anything about difference, those AC121's are only germs I have   

[ghostsauce]

Sounds awesome!

Hmm, a name.. Fuzzymodo.

[DDD]

"...AC121's in my Dad's electronics stuff
Q1 hfe is 325 and leakage is 0,4mA
Q2 hfe is 300 and leakage is 0,5mA..."
IMHO too high values (hfe and leakage current) for usual non-Darlington Ge trannies. It seems there's something wrong with the measurement method.

[Maroslav]

Hfe is just slightly bigger than in datasheet.
Leakage is 500µA and 400µA so it's bad, but it happens

"measuring leakage a higher gain transistor will show more leakage, because the leakage is being amplified"

Q1 (325Hfe, 0,4mA leakage)
A first reading shows 0,98V
0,98/2,472=0,396...mA
A second reading shows 4,23V
4,23V-0,98V * 100=325

Q2(300Hfe, 0,5mA leakage)
A first reading shows 1,23V
1,23/2,472=0,497...mA
A second reading shows 4,23V
4,23V-1,23V * 100=300

[DDD]

Anyway, the circuit produces very impressive tones.
Great!