Anyone interested in building a seymour duncan tweak fuzz?

[wampcat1]

If so, here are some pics I took for an article for the magazine.

http://www.guitareffectsonline.com/diy/tweakfuzz.zip

At first glance, it looks very similar to a fuzzface type circuit. Shouldn't take that long to reverse engineer though, if you're interested in doing that instead of buying one.

Take care,
Brian

[jimbob]

I Do ..but Im also curious about the Seymour Duncan SFX-01 Pickup Booster.

[Marcos - Munky]

Thanks a lot for the pics.

[Phorhas]

"Pick-up Booster"

Do you know of a guitar booster not designed for pick-ups?


oh well...

[Joep]

Great pics!

Any idea on the pot values and tapper (log/lin)?

Thanks,

Joep

[jimbob]

Do you know of a guitar booster not designed for pick-ups?

:shock:  :lol:  :lol:

[wampcat1]

Great pics!

Any idea on the pot values and tapper (log/lin)?

Thanks,

Joep

Not sure of the taper, but the gain is 500k, and (IIRC) the volume is 100k.
Hope that helps!
Brian

[wampcat1]

I Do ..but Im also curious about the Seymour Duncan SFX-01 Pickup Booster.

IIRC I was thinking that Andy (dragonfly) took one apart and said your basic lpb1. Don't quote me on that, though!

[brian wenz]

Hello Hello--
    CRAP...I can't get the pics to download.......
    bugger--bugger--crap-crap.....
Brian.

[cd]

It's a straight ahead FF clone with input cap switching; change 33k to 22k, use 470 ohm and 8.2k, and a 22uf on the GAIN pot.  BTW I would triple check the values of the pots, 100k seems plausible for volume but 500k seems a bit large.

Oh yeah, the input cap values are:

2.2u (the electro, can't see it clearly, but a safe guess)
.12u
.068u
.0047u
.01u
.033u

Also put a small value cap on the input transistor from base to collector, and a 100ohm series input resistance AFTER the input cap.

[cd]

Also, as far as I can tell (since the rotary switch obscures the PCB) with the input cap switching: the end of the caps that go to the input transitors are all tied together.  The "input" of the input caps all have their own individual 100k pull-down resistors, and the "input" of the input caps are switched.  In other words, ignoring the bypass switching (which is a vanilla true bypass using a 3PDT) the guitar signal goes to the common of the rotary switch, and the switch then selects between caps.

[cd]

Forgot, the transistors are SMD 2N3904s.

[cd]

Hmmm come to think of it, 500k as the Gain pot makes sense with the input cap switching, it would reduce gain but with the frequency response changes of the input cap switching, it would be useful.  Hmmm, time to try that one out.

[Fret Wire]

Forgot, the transistors are SMD 2N3904s.

Ok, it's NPN. It would be interesting to check a couple more units to see if they used standard values for Q1 & Q2's collector resistors, or they actually attempted to bias them individually. Probably not. I'm always curious which manufacturers will go through that trouble. For a homebrew, you'd use your own q's, and bias up accordingly. It would probably like Q's of 150hfe and up.

Nice pics, Brian.

[brian wenz]

Hello Hello--
     still can't get the photos............shit...
 Yeah, it seemed that it was a FF variation.......I put a  Gagan-style input cap pot in my "clone" awhile back [instead of a switch] that goes from 2.2uf to .0068uf.   As I get closer to the .0068 alot of the "oomph" and fuzz goes out of the pedal.....too much high end.
 So the Tweak uses 2N3904 transistors?   I wonder if the Afro Fuzz is PNP [in order to match up with a germ tranny]
It almost doesn't seem worth it to build one.....no big deal here!
Brian.

[Fret Wire]

Nope, just a Si fuzz with a cap selector. It's more interesting to see how they build em.

[cd]

Forgot, the transistors are SMD 2N3904s.

Ok, it's NPN. It would be interesting to check a couple more units to see if they used standard values for Q1 & Q2's collector resistors, or they actually attempted to bias them individually. Probably not. I'm always curious which manufacturers will go through that trouble. For a homebrew, you'd use your own q's, and bias up accordingly. It would probably like Q's of 150hfe and up.

Nice pics, Brian.

No need to bias for individual Si transistors, they're consistent enough in terms of gain that one set of values will work for all (of a given type, of course).

[wampcat1]

Hello Hello--
     still can't get the photos............shit...
 Yeah, it seemed that it was a FF variation.......I put a  Gagan-style input cap pot in my "clone" awhile back [instead of a switch] that goes from 2.2uf to .0068uf.   As I get closer to the .0068 alot of the "oomph" and fuzz goes out of the pedal.....too much high end.
 So the Tweak uses 2N3904 transistors?   I wonder if the Afro Fuzz is PNP [in order to match up with a germ tranny]
It almost doesn't seem worth it to build one.....no big deal here!
Brian.

Hi Brian --
Are you able to download the zip file? Are you then extracting it? If not, that is probably where your problem with the d/l is.
OH! You are on a windows computer, correct? I don't think mac's can open .zip files.

If nothing else, I can upload the pics individually, but it would be a bigger download for you.

Thanks,
Brian

[Fret Wire]

No need to bias for individual Si transistors, they're consistent enough in terms of gain that one set of values will work for all (of a given type, of course).

In the same manufacturing batch (or run), they are pretty consistant. Overall, even 3904's can very from around 150 to about 300hfe. You're probably right, if they order a decent amount of one manufacturing lot, they can sample enough trannys to set bias values for the whole batch. They next batch, however, they'd have to re-sample, and re-adjust.

If they ordered 5,000-10,000 trannys, they wouldn't even worry about it. By the time they run out of one specific batch, it won't be in production anymore....on to the next fad.

Funny, in 20 yrs, kids will be modding these with their smd stations.

[cd]

OH! You are on a windows computer, correct? I don't think mac's can open .zip files.

Oh come now, let's not propagate THAT bit of BS.  Macs can open .ZIP files, .RAR files, whatever, as long as you've got a recent version of Stuffit Expander installed.