tonebender MKII build / schematic recommendation

[fuzzy645]

So I'm itchin' to build a Tonebender MKII.   Anybody have any recommendations on schematic, as well as which tranny's sound best in there or any other advise.

BTW, I heard a youtube clip of the Throbak Stone Bender and it sounds pretty darn amazing to me: https://www.youtube.com/watch?v=4nKbHyKgiFg 

[Kesh]

For npn 2N3705s sound pretty good in mine. hfe around 130.

[Mustachio]

I built this one and its great!

http://www.diystompboxes.com/smfforum/index.php?topic=93282.0

Has a charge pump so it will run with regular power. Pure Jimmy page sound!

I used 2 russian GT308B ufo's and an ac128K for Q3.

[LucifersTrip]

So I'm itchin' to build a Tonebender MKII.   Anybody have any recommendations on schematic, as well as which tranny's sound best in there or any other advise.

The DAM forum is prob your best bet for accurate MKII info...ie, stuff like this:

http://stompboxes.co.uk/forum/viewtopic.php?f=10&t=7185&p=110299#p110299

There's many good schematics floating around, like:



Like most fuzzes, the actual model # transistor means very little (unless you're selling clones to the general public who don't know any better). It's all about the gains and maybe more importantly here, the leakage.

[Mustachio]

What lucifer said is correct you can really use many different trannys. I believe a lot of people build these with OC76 or something. I happened to have the gt308's and ac128's on hand. The russian gt308s are known for low leakage and low to medium gain which was great for q1 and q2. The ac128 has a lil higher gain which worked great for me in q3.

Also the layout scruffie made is nice with the 2 trimpots lets you dial it in nice

[fuzzy645]

Thanks guys. I'll let you know how I make out

One other question.  What about ideal gain and leakage for all 3 tranny's?   Should all 3 be in the 100-130 HFE range with very low leakage, or can you get away with using something leaky in one or more of the spots?

[LucifersTrip]

Thanks guys. I'll let you know how I make out

One other question.  What about ideal gain and leakage for all 3 tranny's?   Should all 3 be in the 100-130 HFE range with very low leakage, or can you get away with using something leaky in one or more of the spots?

It seems that usually the MKII is built with higher leakage transistors to get the "authentic sound", but it is a total experiment on your part to find what you really like best. In the end, it is best to build multiple ones....

The low leak ones that Mustachio used could very well sound totally cool, but probably won't get the vintage sound, since you won't get the gating or near gating from a higher leak Q2.  Though, the low leak Russians are perfect for the Darlington pair in a MKIII or Buzzaround.

For ex, look at what Electric Warrior was using:
http://stompboxes.co.uk/forum/viewtopic.php?f=10&t=7185&start=20
"gains were 96, 135, 68. plenty of leakage: 610µA, 525µA, 525µA"

I have built many and it's always Q2 that is most difficult to choose. Depending on the leakage, it will control how much gating you'll get and how strong the fuzz/saturation is. I always wind up getting Q1 & Q3 exactly how I want, then running thru a bunch for Q2 till I like it.

[sgmezei]

Hey guys I am itching to build a PNP MKII as well. I have a bunch of transistors from Luciferstrip and some Russian germaniums too. I have been searching perf/vero layouts and am having trouble picking one. I have "mojo" axial caps already ordered so I would like to use those for the build.

Any recommendations for layouts?

[LucifersTrip]

Hey guys I am itching to build a PNP MKII as well. I have a bunch of transistors from Luciferstrip and some Russian germaniums too. I have been searching perf/vero layouts and am having trouble picking one. I have "mojo" axial caps already ordered so I would like to use those for the build.

Any recommendations for layouts?

always cool to check turretboard.org for that stuff. Here's one for the Supa Fuzz/MKII

http://www.turretboard.org/?p=385
http://www.turretboard.org/wp-content/uploads/2011/02/Marshall-Supa-Fuzz-MK2.pdf

[jrod]

Recently there was a thread on the DAM forum regarding a Marshall Supa Fuzz that David Mains repaired that had low gain transistors for Q1 & 2 and both were low leakage. Which is odd because Q1 should usually be leaky in order to bias.

I've breadboarded this circuit and found that OC75's sound the best. I don't know why because most circuits (like the Fuzz Face) sound exactly the same to me not matter what part number I use as long as the gain and leakage are similar. But with the MKII Tone Bender, OC75's really sound different and better to me. There seems to be a variation in tone depending on what gain and leakage you try in different positions. All the American transistors I tried like 2N1305 & 2N404 were very noisy as well as Russian GT404 (or maybe it was GT402, whichever is PNP). The Throback Stone Bender uses 2N404's and the demos I've heard sound pretty good though.

I also tried a few different Japanese transistors. 2SB77's sounded really good, which are pretty close to OC75's on paper. 2SB175's also sounded pretty good, too.

Anyway, just thought I would throw this out there. I have found this circuit to be really interesting because of the variations in tone that I found. Soon I'd like to tinker with some low gain transistors and see how they sound since I read that DAM thread.

[joegagan]

for some backup or additional info on jrod's comments, i have a customer in cali ( studio guitarist, very good ears ) who owns both the DAM and throback tonebender mk2. he bought the throback so he could throw it back in his car at the end of the gig. ( kidding, he wanted a backup for the valuable DAM, plus prefers the smaller throback enclosure for his pedalboard.)

his comments to me about the tone on two occasions were that the throback was excellent , and very close to the DAM unit, but that the DAM fuzz had something more special in the mids and sounded a little better overall.

[sgmezei]

Hey guys I am itching to build a PNP MKII as well. I have a bunch of transistors from Luciferstrip and some Russian germaniums too. I have been searching perf/vero layouts and am having trouble picking one. I have "mojo" axial caps already ordered so I would like to use those for the build.

Any recommendations for layouts?

always cool to check turretboard.org for that stuff. Here's one for the Supa Fuzz/MKII

http://www.turretboard.org/?p=385
http://www.turretboard.org/wp-content/uploads/2011/02/Marshall-Supa-Fuzz-MK2.pdf

Awesome. Thanks!