The Blackfire is a screamer!

[jmusser]

I spent several hours building Joe Davisson's Blackfire Overdrive last night, but it was well worth the time. It has a huge amount of gain, as you might expect, from five 2N5089s. Basically, it has a whole lot of everything, no matter where your guitar volume is adjusted, or what pick up you're on. The sustain is almost in the same league with the Big Muff, or Whisker Biscuit. It has a rolling boil break up that seems to go on for a week. I haven't gotten into Overdrives too much really, so I still have several to make to compare this one to, but I can't see you getting a whole lot better quality overdrive even from a commercial source. I have Joe's "Vulcan" in cue, and I have have a sneaking suspicion that with the diodes in the design, it'll make a wonderful overdrive for my Si amp, on the order of his Antiquity Fuzz. The main contender for any overdrive that I'm going to build, is going to be the 3 Legged Dog I use with my solid state amp. Any Overdrive will be hard pressed in my estimation to beat that combination. I still like it's tone better, but that's personal preference only. This is a GREAT overdrive period, and I believe anyone would be pleased to have it in their arsenal. I would love to hear this thing through a Marshall. It would have to be wicked. As usual Joe, great job!

[petemoore]

  I turned my Buddy Bill on to a 'blind' Blackfire [and other circuits], test.
  He said "What's that One"?..
  I said "Blackfire"...a small amount of "Serious Distortion' talk followed, but was squelched by long, loud jam.

[WGTP]

I know that's right.  The Vulcan has great "squish" for more of a tubish feel.  Both are favorites.   

[MartyMart]

There's a Blackfire and Vulcan layout in my Gallery above :
http://aronnelson.com/gallery/Martys-layouts-and-photos

MM.

[Paul Marossy]

I like the Blackfire with a Marshall tonestack. That's how I built mine. 

[jmusser]

Hey Paul, do you have a sketch of your version with the tone stack? That would have to be awesome. To me, this distortion has a little bit of the Marshall quality to it to start with. I believe what I'm really looking for, is the ultimate in tubish squish, so the vulcan may end up being the one. I need to order a chip for Mark's 49er OD, and give it a try. The 3 Legged Dog got as close to the tone that I've always had  in my head and that I was looking for. That tone may be nothing more than good old fashioned overdriven tube meltdown. I love the different fuzzes, and their individual voices, but for an every day tone, I think it's going to be tubish.

[Paul Marossy]

Hey Paul, do you have a sketch of your version with the tone stack?

I did a add-on PCB for it. It's simply stuck onto the output of the Blackfire. Here it is.

[Toney]

What an excellent and neat little "add on".
Thank-you for that one Paul, I'll definitely be using it too.

Toney.

[squidsquad]

Heheee...Jeff is still rollin along...cranking em out.  I was gonna ask if you'd ever built a Rocket Fuzz...I love mine.  But now you've moved on.  I'm curious how you'll like the Vulcan.  I always meant to make one...w/some tweaking of the resistors to lower the gain a bit.  But....I have no time at the moment.

[gaussmarkov]

Heheee...Jeff is still rollin along...cranking em out.

yeah.  he's smokin' ... or maybe his soldering iron is.    go, man, go!  thanks for all the reports ... you are adding circuits to my todo list.

[jmusser]

Yea Squid, I've kind of been on this quest to build some of the vintage fuzzes to see what they sounded like back in the day. Some of them are pretty intense, and some of them are just so so, but you don't know until you build them. I built The Rocket about 5 years ago, and haven't had it out for awhile. I can't remember exactly what it sounded like. I believe it was either my second or third build. Thanks Paul for the tone stack wiring. I don't have a lot of time to do building much with my son's marching band schedule, since my wife and I are heavy into the band boosters, but right now, he's in between football and basketball seasons, so I'm making up for lost time. What I really need to do, is go through a boxing up frenzy! I have several more circuits in que to build. I'm going to have to break down and order some parts for things other than fuzzes. After stripping so much stuff out of old tape decks and VCRs, I doubt I'll ever run out of intrconnecting components, but I'm needing specific chips, pots jacks and switches now to build some of the circuits. Switches and jacks you run out of pretty quickly, and there always seems to be a pot value that you're missing.

[Paul Marossy]

What an excellent and neat little "add on".
Thank-you for that one Paul, I'll definitely be using it too.

Toney.

I'm glad that you like it. 

[audioguy]

Paul-
That tone stack- are those pots Log or Lin?

[Paul Marossy]

Paul-
That tone stack- are those pots Log or Lin?

AFAIK, the "standard" Marshall tone stack uses linear pots for the treble & mid and a log pot for the bass.

[jmusser]

Paul, could you clarify the two middle cap values of the Marshall tone stack? I can see a 33K resistor in red, then 70pf next to it, which I'm guessing is 270, 470pf, etc.,  because I can see a hint of green behind the pad. The next one I'm guessing is a .022uf, but I can't see the dot for the pad. The last cap on the far right is clear, and is a .022uf.

[Paul Marossy]

Paul, could you clarify the two middle cap values of the Marshall tone stack? I can see a 33K resistor in red, then 70pf next to it, which I'm guessing is 270, 470pf, etc.,  because I can see a hint of green behind the pad. The next one I'm guessing is a .022uf, but I can't see the dot for the pad. The last cap on the far right is clear, and is a .022uf.

That's a 470pF and a 0.022uF cap. I should have changed the color of that layer to grey so it would be more readable. I was in a hurry, as usual. 

[jmusser]

Thanks Paul!

[Paul Marossy]

Thanks Paul!

You bet. Let me know how you like it with that tonestack on there.

[audioguy]

I built a blackfire and added the Marshall TS and it sounds amazing... however...

I have to have the volume all the way up to get unity gain going into a tube amp. Going into a solid state amp it works just fine... nice and loud! do I need to buffer it or something?

Any thoughts?

[robotboy]

Agreed. I built the Blackfire for a friend. He uses it in front of his Marshall JCM800. Sounds amazing.