freestompboxes.org

Dragonfly's:

It's the one from DIYSB gallery? It's different to edkoppel's (different collector biasing and gain stages input resistors), but similar to the first one in this tread

Yup. I figured if it's a Big Muff, maybe the degree of variation between units is also BMP-like.

Sinner, if you leave that cap out you're getting a DC path from collector to ground, upseting the bias (and gain) of the stage. Either before the tonestack, or where you drawed it originally would be fine, as long the cap value is big enough.

Regards,
Juanro

sinner wrote:Look here, it cant be before tonestack

Ok, I see it now! Thanks!

juanro wrote:Sinner, if you leave that cap out you're getting a DC path from collector to ground, upseting the bias (and gain) of the stage. Either before the tonestack, or where you drawed it originally would be fine, as long the cap value is big enough.

Regards,
Juanro

So it makes sense? The cap value is 22nF

[quote="sinner]So it makes sense? The cap value is 22nF[/quote]

Yes.

ok, it was nice and sunny out today, so I got to take some more pics.
hope they help!
(if they are too big, right click and view the image)

Great picts

Schemo almost done, just two missing values

Could you help me to fill it out?

Looking on layout posted earlier:
- C6 cap - I think it should be 100nF (.1Z code)
- C9 cap - I think it's around of 3n9 (392 code, or something like that)

Thanks a lot for all

C6 = .1Z 10v
C9 is kind of hard to read.
it the first two numbers are half there so it looks like it says either:
"3047 K 100" or
"0047 K 100" or
"2047 K 100"

I could try and take a pic, but i think you would see the same thing.

edkoppel wrote: it the first two numbers are half there so it looks like it says either:
"3047 K 100" or
"0047 K 100" or
"2047 K 100"

I could try and take a pic, but i think you would see the same thing.

it's 4n7 You're awesome

So it's done. I'll have a look on the other unit picts posted here, and soon I'll post the final schemo, and vero layout

Thanks again

Any other unusual BMP vintage variants/clones you know about?

cool!
glad you figured it out.

well, big muff variations are what i mostly collect.
Besides the Dyna Soar Fuzz, that I am playing right now and sounds really amazing!
I have a few more weird japanese ones.
One of them that I have wanted to know just what the hell it is, is the Vestax Fuzz from (i think) the 80s.
It sounds like a really high gain Civil War muff but with an upper octave.
its pretty weird.


that might be a good one to post.

this:

edkoppel wrote:this:

Bring it on, I'll be more than happy to crank it

Somehow I missed this thread. I could have saved you the trouble. Had a page about the TDB here.
http://www.kitrae.net/music/History_of_ ... #HohnerTDB
And the schemo.

Now then, lads! I'm close to making a decision on my next build. It's decided on my next build and it's going to be a clone of this fine Hohner Tri-Dirty Booster. Thank you all in this thread for the work you've done.

I was wondering if you could help me out a bit with the the transistors, the 2N5172 that are in the original aren't exactly that high in the Hfe department. (100-500)
Would modern 2N5172 be all right and if so, what gain range is best suited for the Tri ? Or are there better suited trannies for this particular pedal ?

thank you

Cub wrote:Now then, lads! I'm close to making a decision on my next build. It's decided on my next build and it's going to be a clone of this fine Hohner Tri-Dirty Booster. Thank you all in this thread for the work you've done.

I was wondering if you could help me out a bit with the the transistors, the 2N5172 that are in the original aren't exactly that high in the Hfe department. (100-500)
Would modern 2N5172 be all right and if so, what gain range is best suited for the Tri ? Or are there better suited trannies for this particular pedal ?

thank you

That's an interesting question you bring up. There's an electronics surplus store near me that has a few giant boxes of 2n5172's (the old ones), and so I've bought a few hundred from them over time. I would say that you're right, most 5172's are not on the high end of their spec. I went through all that I have and sorted them by gain, and I'd say somewhere around 10% or less are at the high end (400-500). But I have built the Tri Dirty Booster with these, and honestly, it roared even without my HIGHEST gain transistors. I'd say you could probably get away with 350 or so... but it's a taste thing, you should try out some different, commonly used Big Muff transistors (5088's and the like) and see what sounds best to you.

In a lot of ways the 5172's are like the 5133's that were in some of those early muffs... very hard to find transistors that measure on the "high end" of the gain spectrum.