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I've built a bunch of Fuzzrite stompboxes and was curious what varieties are out there.

I started with the germanium version:


then, I built the silicon version:


I've built numerous variants, including the one that for my taste beats em all...the germanium Orpheum:


It wasn't until relatively recently that someone posted the schematic for the one in the BG-500 amp:
http://www.planktones.com/Mosrite%20BG- ... tic/11.jpg

...which I cleaned up for easy building:


It's definitely has a bit fatter tone (closer to the Orpheum) than the one in the standalone box (note the larger output caps). I liked this better with germanium, so I built it that way. Details:
http://www.diystompboxes.com/smfforum/i ... #msg837558

According to others, it's the same circuit as in the BG-1000 amp, correct?

Though, I recently saw the post here about the 400 amp that also has a built in Fuzzrite (which is one of the reasons I joined):
http://mosriteforum.net/forum/viewtopic ... c523d3f991

What Fuzzrite circuit is in that? Are there other Mosrite amps with built in Fuzzrites that differ further?

thanx much

In the stompbox thread (re: fuzzrite in Award amps) you linked to you changed the NPN transistors to PNP. Any particular reason for the change? A better selection of germanium PNP than NPN?

Brinkman wrote:In the stompbox thread (re: fuzzrite in Award amps) you linked to you changed the NPN transistors to PNP. Any particular reason for the change? A better selection of germanium PNP than NPN?

exactly...

I do have many ge NPN's that would work here, but I usually save em for when I really need (-) ground.

Also, the datasheets I sourced for the 2N2926 transistor both spec'd a min Hfe of 35 (35-470 being the full range). Above I see you list it at 100. What datasheet gave you that?

ElT wrote:I've built a bunch of Fuzzrite stompboxes and was curious what varieties are out there.

It wasn't until relatively recently that someone posted the schematic for the one in the BG-500 amp:
http://www.planktones.com/Mosrite%20BG- ... tic/11.jpg

...which I cleaned up for easy building:


It's definitely has a bit fatter tone (closer to the Orpheum) than the one in the standalone box (note the larger output caps). I liked this better with germanium, so I built it that way. Details:
http://www.diystompboxes.com/smfforum/i ... #msg837558

According to others, it's the same circuit as in the BG-1000 amp, correct?

thanx much

Yes, it's the same circuit in the BG-1000. Thanks for cleaning up the schematic! I know the one I posted is not easy to read. If you haven't already seen it, there is a demonstration of the BG-1000 Fuzzrite at

-Marty

Say, that was a really nice amp/vs. pedal Fuzzrite demo.

I have several Mosrite amps and two have the built in Fuzzrite. One is the BG 1000 and one is the 400 designed by Sanner. I like the sound of the Fuzzrite in the amps better myself. I sold my pedal a while back because I felt it did not have the depth that the amp Fuzzrite's had. The amps are rare and I think they have a good sound. Some guys don't take them too seriously, and I can't exactly say they would replace a Fender, nor are they road worthy, but they do sound good as you can tell in this demo and are a great rec room or recording amp for guys into this style of music. They were a very expensive amp at the time. I wish they put a Fuzzrite in the model 200 that I have. That little combo amp sounds fantastic! No fuzz though. I have a Mosrite experimental head too that has no Fuzzrite. Those poor fuzzless amplifiers!

Thanks for posting these schematics. The Fuzzrite is such a simple circuit that sounds so great.

The values of the caps both input and output, will change the tone and overall feel of this circuit. If the input caps are too small there will not be enough signal to drive the transistors, but if they are too big they will allow for too much drive and the sound will get muddy and too thick.

Hopefully when I get caught up I'll try and build a Germanium version like yours to see how it sounds.

Brinkman wrote:Also, the datasheets I sourced for the 2N2926 transistor both spec'd a min Hfe of 35 (35-470 being the full range). Above I see you list it at 100. What datasheet gave you that?

I use this for much of the vintage stuff.
http://transistor-spravochnik.ru/descri ... n2926/2664
It's been pretty accurate, but of course it could be wrong:

I see the US datasheets you're speaking of, which is most likely correct, 35-470. It's also most likely you won't get one that's hfe 35 or 470. Most vintage silicon fuzzes I've dealt with use hfe 75-200, with the majority 100-150.

thanx

Nokie wrote:

ElT wrote:According to others, it's the same circuit as in the BG-1000 amp, correct?

Yes, it's the same circuit in the BG-1000. Thanks for cleaning up the schematic!

I know the one I posted is not easy to read. If you haven't already seen it, there is a demonstration of the BG-1000 Fuzzrite

...and thanx for the confirmation and excellent video. I did watch it already...multiple times!

Bob Shade wrote: I have several Mosrite amps and two have the built in Fuzzrite. One is the BG 1000 and one is the 400 designed by Sanner.

Is there a difference between the fuzz sound in those two?

I like the sound of the Fuzzrite in the amps better myself. I sold my pedal a while back because I felt it did not have the depth that the amp Fuzzrite's had. I wish they put a Fuzzrite in the model 200 that I have.

well, you have the schematic for the fuzz in the amp! try a germanium one at it'll even be richer. you won't have nearly as much of the harsh highs...but can still get that if you want with a simple mod.