Ashbass - FUZZbrite

analogguru · Post by **analogguru** » 26 Nov 2007, 03:52

Maybe you won´t believe it, but "ashbass" himself is bidding on this Mosrite Fuzzrite:

https://cgi.ebay.com/1960s-Mosrite-of-C ... dZViewItem

I thought he is the only one already with the secret recipe...? Does he need to update his secret schematic ? Hmmm.... For this he doesn´t need to buy this unit, he only has to visit the sellers homepage:
http://www.reinmoser.com/Mosrite.htm

As you can see there, it is the second version (ungooped) Fuzzrite with 4 x 470k and two TZ82.

analogguru

soulsonic · Post by **soulsonic** » 26 Nov 2007, 03:59

Heh, maybe he collects them.

HonkyMofo · Post by **HonkyMofo** » 14 May 2009, 20:00

Hi. I've been looking around the web for Fuzzrite info and I found a pic that Ashbass had posted at the TGP forum of the ungooped guts of his Fuzzbrite. From the pics it looks like it is the same as the popular TZ82 schematic with (4) 470K resistors but with one additional resistor to ground from the collector of Q2. That would make it different from posted schematics as he claims but it looks like there are at least 4 versions of the circuit now: germanium, silicon w/ 4 resistors. silicon w/ 5 resistors, and encapsulated.
Thread here: http://www.thegearpage.net/board/showth ... 787&page=4

The pic is B&W so you can't read the color codes and I think there is another capacitor hiding behind the large one.

analogguru · Post by **analogguru** » 14 May 2009, 20:50

That would make it different from posted schematics.....

maybe

.... as he claims but it looks like there are at least 4 versions

wrong....

... of the circuit now: germanium, silicon w/ 4 resistors. silicon w/ 5 resistors, and encapsulated.

.... because the "silicon w/ 4 resistors" always contained 5 resistors. The fifth resistor is a 22k to ground placed directly at the potentiometers.

Not verified yet is if the encapsuled version is identical to the silicon version.

analogguru

theehman · Post by **theehman** » 14 May 2009, 23:07

If you look at the silicon schematic circulating on the 'net it doesn't have the 22K to ground Analogguru mentioned. I RE'ed a ZB Custom rebranded Fuzzrite years ago and it did have the resistor in it, which actually goes from the junction of the .002 cap from Q2 and the lug of the Depth control to ground.

What does the 22K do in the circuit? I've seen the same arrangement in other fuzz circuits.

soulsonic · Post by **soulsonic** » 14 May 2009, 23:39

theehman wrote:What does the 22K do in the circuit? I've seen the same arrangement in other fuzz circuits.

High pass filter

analogguru · Post by **analogguru** » 15 May 2009, 00:23

theehman wrote:If you look at the silicon schematic circulating on the 'net it doesn't have the 22K to ground Analogguru mentioned.

I don´t care much about wrong schematics on thew net - there are too many.

In the actual units there was this 22k resistor - in both versions - as you can see below.

What does the 22K do in the circuit? I've seen the same arrangement in other fuzz circuits.

As soulsonic said it acts (together withe the 2n capacitor) as a high-pass-filter.

analogguru

doug deeper · Post by **doug deeper** » 16 May 2009, 00:30

to be fair, the missing 22k resistor does change the sound quite a bit.

Uma Floresta · Post by **Uma Floresta** » 18 May 2009, 22:06

Silly putty? Bubble gum?

theehman · Post by **theehman** » 18 May 2009, 22:17

Uma Floresta wrote:Silly putty? Bubble gum?

Bondo is what I've read.

Fuzzer · Post by **Fuzzer** » 18 May 2009, 23:39

The chewing gum is bondo. It is there to protect the parts inside.

That says the builder.

soulsonic · Post by **soulsonic** » 19 May 2009, 05:21

Fuzzer wrote:
The chewing gum is bondo. It is there to protect the parts inside.
That says the builder.

Should say, "It is there so I don't have to bother making a board for it."

Fuzzer · Post by **Fuzzer** » 19 May 2009, 13:15

There is bakelite, FR4, turrets, eyelets,... bondo.

HonkyMofo · Post by **HonkyMofo** » 20 May 2009, 14:10

I have successfully de-gooped a Fuzzbrite belonging to a friend. The pictures show the standard 5 resistor circuit (4 x 470K and 1 x 22k). It's exactly the same as the schematic theehman posted except the transistors are PN2222A (labeled CENPN 2222A) . The pot values are also the same.

: ashbrite1.jpg (22.32 KiB) Viewed 2590 times

: ashbrite2.jpg (21.86 KiB) Viewed 2587 times

My first de-goop!

Uma Floresta · Post by **Uma Floresta** » 20 May 2009, 14:33

HonkyMofo wrote:I have successfully de-gooped a Fuzzbrite belonging to a friend. The pictures show the standard 5 resistor circuit (4 x 470K and 1 x 22k). It's exactly the same as the schematic theehman posted except the transistors are PN2222A (labeled CENPN 2222A) . The pot values are also the same.

ashbrite1.jpg
ashbrite2.jpg
My first de-goop!

I'm surprised he's not using the the metal can 2N3904 or whatever transistors from the original. If you're going to go mojo with the carbon comp resistors, why not go the whole nine yards?

theehman · Post by **theehman** » 20 May 2009, 14:34

Nice work on that. So, it looks like it's the same as my Fuzz-O-Matic, except I use different transistors.
Another mystery laid to rest.

theehman · Post by **theehman** » 20 May 2009, 14:43

Uma Floresta wrote: I'm surprised he's not using the the metal can 2N3904 or whatever transistors from the original. If you're going to go mojo with the carbon comp resistors, why not go the whole nine yards?

The original transistors were TZ82 made by Sprague. Hard to find these days.

Uma Floresta · Post by **Uma Floresta** » 20 May 2009, 14:58

theehman wrote:
Uma Floresta wrote: I'm surprised he's not using the the metal can 2N3904 or whatever transistors from the original. If you're going to go mojo with the carbon comp resistors, why not go the whole nine yards?
The original transistors were TZ82 made by Sprague. Hard to find these days.

Ah, thanks for correcting me.

Sardon · Post by **Sardon** » 21 Oct 2009, 22:15

Can anyone suggest some ge and si substitute transistors and their values? Thank you

chicago_mike · Post by **chicago_mike** » 21 Oct 2009, 22:25

PLAYDOH!