Fuzz build suggestions, GE transistors

[cbriere]

HI,
Need your suggestions to build a Fuzz box using the GE transistors i got (NPN's)
i really like the Steve ASlbini video demonstrating the Harmonic Percolator,

http://www.youtube.com/watch?v=aVUN9j9ihEM
Please suggest me a build that come the closets to this soune (HP)

tks, chris

[Dragonfly]

HI,
Need your suggestions to build a Fuzz box using the GE transistors i got (NPN's)
i really like the Steve ASlbini video demonstrating the Harmonic Percolator,

http://www.youtube.com/watch?v=aVUN9j9ihEM
Please suggest me a build that come the closets to this soune (HP)

tks, chris

ummm....  why not just build a Harmonic Percolator ?   

Also, Doug Hammonds "Brick" is a Perc variant that sounds great. IIRC, MarkM has a layout in his gallery.

You'll need to make some adjustments for the NPN germ, but that shouldn't be too tough.

[cbriere]

Allright,
i found the schematics for the BRICK,
(outoff wayback machine because it seems Doug has closed its site!?!?!!)

Anyone had succes with this circuit, pls comments/suggest mods.!!!

[mac]

maybe you want to look at this thread:
http://www.diystompboxes.com/smfforum/index.php?topic=55987.80

mac

[ambulancevoice]

build a bazz fuss with a germ npn!!!

[col]

I quite like the brick, it has areally nice tone but it doesn't match the Easy face IMO. I did a post a couple of weeks ago after re-building my easy face as an NPN version. It is a simple circuit, small parts count and sounds fantastic. I'd guess you could use just about any Si NPN as the first transistor as well. I'd also suggest you build an NPN rangemaster to go with it. For these two pedals you'd simply have to turn all the electrolytic capacitors round from the PNP original circuit. Do a search on here for both.

[MartyMart]

Chris, I'm loving my John Hollis "Rockface" with Russian PNP's in it, it's a temp stabalized FF but has
a great sound to it with these 308's
You can reverse it to an NPN Ge easily enough, second choice would be a Roger Mayer Classic FF
It's setup a little differently for more output and is a good one, a LOT depends on the trannies and the
bias/caps used ...... as I'm sure you know !!
MM.

[cbriere]

Well,
i prototyped the schematics for "THE BRICK" last night, with approximate values.
I tried lots of differents GE PNP i got (witch i have tested and i know they are leaky and low gain)
On the 20 parts i tried, there are 2 or 3 that gives pleasent sound. Most of them gives muchy, no gain sound.

Next try i must do is, keep the good sounding parts and tweak the 4 resistors. to see if i can get any better.

BUT, my general observation on this circuit is that it has different sound than typical FF circuit.
(better IMHO) but it seems to be alot dependent on GE transistors specifications

chris

[Dragonfly]

Well,
i prototyped the schematics for "THE BRICK" last night, with approximate values.
I tried lots of differents GE PNP i got (witch i have tested and i know they are leaky and low gain)
On the 20 parts i tried, there are 2 or 3 that gives pleasent sound. Most of them gives muchy, no gain sound.

Next try i must do is, keep the good sounding parts and tweak the 4 resistors. to see if i can get any better.

BUT, my general observation on this circuit is that it has different sound than typical FF circuit.
(better IMHO) but it seems to be alot dependent on GE transistors specifications

chris

It's definitely VERY different than a FF. You mentioned digging Albini, and, amidst all the "versions" of the HP, IMO, The Brick is one of the best.

Be sure to post pictures of your build and a "build report" when you complete it

[mac]

• I wrote about the all Ge Bazz Fuss, using two Ge in a darlington config:

http://www.diystompboxes.com/smfforum/index.php?topic=55004.0

• FAIM fuzz. It uses two Ge and it is temp stable:

http://www.diystompboxes.com/smfforum/index.php?topic=51210.0

also check marty's gallery for his modded version and clip.

mac

[cbriere]

i like the idea of classA type of circuit using transistor, Germanium type here.
but the sound clips of the FAIM and BAZZ FUZZ are not really convincing 
they sound like a dull big muff. 

[cbriere]

I have now moved away from the Percolator circuit,
because i could not tune (playing with the 4 resistors values, swaping transistors) the circuit to have
enough gain and also i could not remove the muddy sound of it.

This now has become "what's the best circuit to build with GE transistors"
I tried the tonebender MKII ,  here
http://fuzzcentral.ssguitar.com/mkII.php
i have NPN's and found it to sound alot better than the Perco.
as the text says, it can reproduce the LED ZEPPELIN I and II sound (think: "whole lot a love" starting riff)  perfectly.

the adventure continues....

cbriere

[mac]

About the bazz fuzz home-made darlington version, try this mods:
• I built one for a friend and the collector resistor was near 22k to sound good with two BD139s hfe = 200. With the std 10k it sounded out of focus. The collector resistor should be a trimmer.
• I noticed that a resistor between q1 emiter and q2 base focuses the sound a little more, much like the TB 3-knob. Also, med gain Ge leaking as much as 200ua can be used without the need of decreasing the collector far below 10k.
• A second revered diode from C to B. Or a diode from q2 C to q2 B.
I'm drawing the schem to post it.

About the HP, IMHO the Hermida version is not easy to tune. To me the best Ge is a PNP hfe=40-70, leakage=100-200ua. The NPN must be a Si or a Ge low leakage, less than 50ua. And the diodes can be a problem. I prefer Si ones, 400x.
The circuit can be easily reversed if you have Ge NPN and PNP Si.
The barge version with two Ge, well, I guess leakage can be a problem.

Anyway, the TB is a good choice.

mac