Dinosaur Fuzz PCB!

[phillip]

Here's my new Dinosaur Fuzz PCB.  I just finished working on it yesterday, so needless to say, it's untested.

NOTE:  Layout is for NPN transistors and negative ground, the original is PNP transistors and positive ground.  I also chose to use the AVX boxed metal film 1uF metal film capacitors instead of the 1uF electros that are spec'd in the original schematic.  

Let me know if there are any errors..





Phillip

[BILLYL]

Phillip-

Where is the orginal schematic located???

BILL

[phillip]

Here it is:

http://www.ampage.org/sounds/files/newdinofuzzschem2.gif

Phillip

[Zak Mc Kraken]

Hi,

Do you have built the dino fuzz ? Which kind of transistor is Q2. It is labelled B22 but i cant't find a B22 transistor.

[petemoore]

Q2 of FF type transistor according to the schematic...Phillip's PCB is for NPN type transitors.
 The first two transistors look to be a FF type circuit.

[Zak Mc Kraken]

I've checked and the hfe of 2N3906(Q1)) is between 60 and 300. To stay close to a FF i must choose one of 60-80 and Q2 120-130. An AC128 for Q2 is a good choice ? And what hfe for Q3 ?

[Freddy205]

Nice work Phillip. Are you gonna do a layout for the skyripper? That circuit rocks!

[Arn C.]

Hey Phillip!  I can't seem to get the link(I got from the properties of the pic) for the pic to work.  I see no pic of the pcb.   Do you have another way to see this pcb of the Dinofuzz?  I built this when it first came around(Thanks Joe G.!), but I could never get it to work.

Thanks!
Arn C.

[phillip]

Wow this is a really old post!  I'll have to dust off and repost the PCB and Layout for the DinoFuzz...

EDIT:  Okay, they should be showing up now.  Someone look over the layout and make sure that it matches the schematic before building it!  I haven't tested this circuit board.

Phillip

[Aharon]

Nice collection of schems and PCBs Phillip,way to go!!!!!!!
Aharon

[joegagan]

This looks cool.
I did not take the time to check it tho.
I found that after several hundred  units sold, no one cared about the treble boosting function (.001 cap and 500k trim from output back to base of Q2). most people thought the pedal had too much high end. the stock setting for the trimpot was 'no treble boost'. I developed the pedal playing live gigs trying to cut through a very loud drummer, so for me the treble content was perfect. .

If I had to redesign the pedal, this treble loop would be absent.

One could install a traditional tone control for taming of highs, I like .047 cap to ground for this

In the factory config, the 2200pf capat the input was soldered directly to the back of the gain pot to cut down on radio ( the only reason for this cap).

When built in PNP config, any good ge tranny will work for q2, but I prefer the gainier ones. Most production units had 2n2614s which were very rich sounding and consistent. I don't have any NPN equivs to recommend, does anyone else?

The third gainstage lends itself to experimentaion with diode clippping etc.

The other minor flaw in the design is the hiss that series resistance adds when the gain control or tone control are in the middle. in most cases this was not a prob,  but with certain guitars and setups people didn't like the hiss. I usually kept the tone full CCw(both input caps engaged) and the gain full cw, there was very little noise in this setting.

[puretube]

hiss: maybe somebody oughtta try conductive plastic pots in this place...