A High Gain solution ..... "BLACKFIRE" !

[MartyMart]

With all the recent "Jfet madness" with meteor/Dr boogey/Thunderchief etc, I just
thought that I'd mention Joe's Blackfire circuit.
Super high gain, uses easy to find components, 5089's which are a breeze to get sounding "right" etc etc.
Just SEARCH for "Blackfire" and there's a vero layout in my gallery above.
I got mine out today and was "Blown away" all over again !!

LET"S ROCK !!

Thanks Joe

MM.

[Xavier]

How does it sound compared to the Boogey? I couldn't make my Obsidian work so I still haven't heard any of Joe's circuits.

[MartyMart]

Palm mute type of thing and can do AC/DC stuff too.
Nice full sound and and plenty of top "edge" to it .
No "Mud"

MM

[Mark Hammer]

Lotta power and output in that baby.  Enough that it will easily survive just about any passive tone control solution you want to add to it, whether 3-band tonestack, notch/scoop, BMP style, SWTP, etc.  Responds VERY nicely to changes in the guitar tone control, which not a lot of pedals will do.  Great with a wah in front as well.

[aron]

Great pedal.

[MetalGuy]

It looks like the schematic is not available anymore.

[Rafa]

It was in another thread but: has anyone tryied pedals using 200V mosfet like irf822 which are said to be much closer to valves than common ones like j201 or 2n4547
Cheers
Rafa

[puretube]

GUS`BUZ

[WGTP]

That's what I'm talking about.  With some re-biasing, you can use Mosfets in the BlackFire.   

[MikeH]

That's a pretty serious vero layout.  Does anyone know of a PCB layout anywhere?

[luap77]

Does anybody have a schematic for blackfire please? Thank you.

[brett]

irf822 which are said to be much closer to valves

I think you'll find the JFET configuration is more important than the model.
e.g. tube-like distortion comes from source biasing, no AC feedback, etc.

The blackfire has a monster of a sound.  I'll look for my pcb layout.

[tcobretti]

Does anybody have a schematic for blackfire please? Thank you.

Joe's webpage:
http://www.diystompboxes.com/analogalchemy/

[KerryF]

^-Its not there anymore...

[burnt fingers]

I'm not sure why it's not there anymore so I don't want to post it.  I have it on my Hard drive. 

I guess you can PM me if you want it.  I'll post it somewhere if I get permission.

Scott

[tcobretti]

It is actually still on his site, although not obviously linked.

[MartyMart]

That's a pretty serious vero layout.  Does anyone know of a PCB layout anywhere?

That was quite an early vero attempt .... but it works !
Perhaps soneone could make a smaller one ? 

MM

[Xavier]

I will, later today or early next week

[pyrop]

A link to Gringo's site with his Joe Davisson PCB Pack (Obsidian, Blackfire, Hellfire, Massacre, Cold Cathode, Vulcan, Jfet Vulcan)
Includes PCB & layout for a pos ground BS250 mosfet Blackfire!

pyrop

[brett]

Hi
This Blackfire schematic is somewhat different to the earlier one that I have a layout.  Among other things, that one had a low-pass filter (like the Rat).
This circuit is somewhat unlike the usual ones we see. 
From what I can make out, Q1 and Q3 are a neat type of buffer (1M input impedance, negligible output impedance).  The two gain stages, around Q2 and Q4, seem more conventional (common emitters with bypass caps). 

What do the 10k base resistors do, I wonder?  The 0.0022uF cap and 470k resistor pass high frequencies, with fc=150Hz, so deep bass (for a six string) is cut.

From what I can see, the final stage is has a low-pass filter (220k and 0.001uF), but quite a lot of feedback to the base (220k).  Is that right?

Any comments on how/why this works so well?