still stumped...can someone reccomend a tonebender project that works?

[pinkjimiphoton]

i've looked at so many schems and layouts at this point my eyes are dripping down my cheekbones.
have tried several versions, can't get anything to work, and all seem conflicting.

can someone reccomend an npn negative ground silicon version that actually works, that they've built?
or are they all just a nightmare to get working?

do i need to find a new hobby, or what? frustrated...

thanks in advance!

[Earthscum]

NPN Silicon. I just breadboarded one, and it biased up perfect.

BC108 in Q1, BC109 in Q2. The 108 measured about 250hFE, and the 109 was about 575. Swapping them out with other stuff didn't seem to matter to bias by more than about .1V at the most, so whatever you have should work fine. I even dropped in a 2SK117 jfet into Q2 and it fired right up at a perfect 4.5V bias (actually like 4.53V... perfect enough!)

So, Q1's Collector resistor is 27k, feedback is standard 100k, Q2's collector resistors ended up being 470 Ohm at the top, and a 6.8k on the bottom, with a 1k pot at the emitter, and 22uF cap. I used .22uF input cap and 4.7uF output, but I play bass... and I think it is pretty much overkill, so I'd just stick with the 2.2uF output cap, and .1uF for input. They really didn't sound much different to me, but on guitar it may make it a bit "loose" and flabby sounding.

The key to making this one sound great (imho) is putting a .01uF cap between Q2's Collector and Base. It really smooths out the top end. .1uF made it nice and thick sounding, 470pF just shaved off the piercing highs. Maybe start with a 1n and decide if you want it smoother or harsher.

Just went up and slapped it back on the board really fast, and yes... it biased out at 4.55V. I'd definitely start with a .001uF feedback cap for guitar. The .01 I'm digging on is a little thick for guitar. I may even go back up after this and try out a 4.7n. Damn FF's... now I'm gonna be popping these in and out like I already do with Bazz Fuss circuits. That simple circuit has been such a workhorse for me, easiest stable distortion I've ever built.

[smallbearelec]

Most tone bender circuits are three stages, and every added stage makes it exponentially more likely that you will include a mistake that is fatal to the output. Have you considered starting with a Fuzz Face? My article:

http://www.smallbearelec.com/HowTos/BreadboardSiFF/BreadboardSiFF.htm

documents setting up a Si FF on a breadboard. If you buy my kit, you can't not wind up with a working FF. From there, if you want a TB MK II, adding the first stage would not be hard.

(Note I have added after seeing Earthscum's post): So you want a two-knob TB? That's a FF with few changes in component values. But BREADBOARD IT, as the man says! Try it with the parts in my kit, then buy a few other things to sub and see what you like. The point of doing it solderless is that you get to hear something and know for sure that the components will work if they are All connected properly.

Good Luck!

Regards
SD

[LucifersTrip]

Most tone bender circuits are three stages, and every added stage makes it exponentially more likely that you will include a mistake that is fatal to the output.

That's funny, I was just going to suggest this:



It was one of the 1st pedals I made, and without knowing (or caring about GE/Si difference) I used a silicon for one tran and a germ for the other....and it sounds great.  Since it's a FF variation, it should be cool with 2 Si's.

good luck

[Earthscum]

Lol... yeah, I forgot to mention why I kept referring to a Fuzz Face.... it is the main body of most the tonebenders I've seen schematics of (Jumbo Tonebender is a different beast... basically Big Muff variant... it has worked for me every time I've boarded it). Basically, if you take a FF circuit and add another gain stage in front, you have a tonebender. I just ran upstairs and popped in an LPB in front and, wow... too much for me! Even the Jfet gain I have on my board right now gave it too much boost for my likes, and a buffer made it more gainy, but less "FF" reactive. I'd just start with a FF, and add a gain stage in front that's to your liking. Maybe a tone stack and a buffer afterwards, for fun... because that's what it's all about, having fun. Once you get a circuit that works, you end up playing around with it (and usually going back to the original values, but ya learned something, didn't ya?).

*** Try out the one posted above, but swap cap polarities, battery polarities, and drop in a couple NPN's. That will give you a (IMHO) true "Tonebender" circuit using NPN Si. I just tried it, it works. You may have to tweak Q1's Emitter resistor a bit to get Q2's around the 4.5V mark.

*** Ok, one last mod to this post... I just tried the circuit above using Ge's, since I had it set up. Basically, I wanted to see what low gain tranny's sound like. Wow... I could easily get away with adding a pre-gain stage. I tried a couple ~45hFE's, and I'm thinking it'll sing with a pregain stage. I noticed the original transistors used don't seem to be very high gain, so I tried it. Maybe a couple metal can 2N2222's would work out great for a NPN Si version, or some even lower gain ones... I'm sure Steve has SOMETHING at Smallbear. Should be around 45-65hFE, if I'm not mistaken? Maybe like a 65 in Q1 and a 80 or so in Q2... and you could easily add another low gain stage in front. That 47k feeds back alot of signal.

[pinkjimiphoton]

hi guys, thanks for the replies. i've built several fuzzface variants, and never had any probs  with any (well, the germanium one is a pain with temp changes, i used it the nite i built it live and it was amazing, the next time it was a lot colder and it sounded blatty as all get out. had to hit the case with a cigarette lighter...worked, believe it or not).

but the tonebender things had me stumped. i've built a couple different versions following a couple different layouts, and always end up with the same result for some reason.

this is the one i did a layout for tonite, was gonna be my last hurrah for a while...the woman't ready to eject me.



this is the layout i tried to do for it...



earthscum, is this the one you're talking about, or can ya point me at a link?

i really need to get this thing right for a change...the last couple attempts have been heinous fails!!

[Earthscum]

I just went over that layout, and it looks good. One thing I've noticed people catching is that some stripboard may still have a fine trace connection at the ends of the board... check it, scrape it a bit. I haven't tried stripboard yet, but I'm gonna start checking it out and trying out some of Adriano's layouts.

That schematic should work perfect. The values are really close to some that I've found while fiddling so far. Another thing is to try 3904's in all positions. If that works for you, then reconsider the pin-out of the 5088. I may be wrong, but I think some 5088's are pinned different? Use the diode tester on a multimeter. If you find that 1 pin conducts to 2 other pins, but they won't conduct in any direction, then you found the Base. If it's in the center, your pinout is E-B-C. If your Base is on either side, then it is E-C-B.

[pinkjimiphoton]

thanks for the advice, yes, i've found that with some vero, too...the ends will be connected by almost invisible traces. what i usually do is take a cuttoff wheel on my dremel, and use it to make sure there's no inadvertant contact on the ends of or between soldered junctions..

the last layout i did seemed good, too...but something funky happened!!



i looked up the pinouts on the net, the 5088 i have is right pinout wise, but i have another one too where it's different. i had to get creative with the legs to make it work, but that doesn't do anything, either.

been soooooooooooooooooooooo stumped...and up till now, everythings' gone together pretty well!! i figured a 3 tranny fuzz would be a good stepping stone to more complex projects.

smallbear, i really appreciate the help and advice, but at the moment, don't really have the resources to order a kit from anyone. i have a lot of parts i've accumulated over the years, and am using up my stock on hand where i can cuz being a musician in this economy is pretty tedious, at least around here. at this point, i WANT to do things with vero, not premade pcb's....just my own stupidity, and the fun factor of discovering, fabricating, and finally playing with it seems to keep me going.

if i had a life, maybe things would be different.

anyways.,...thanks to all!! i guess i may as well try and build this variation now, it's not like my girl's gonna get any unhappier about me being absorbed than she is now...lol


girl: "i thought that your were done building pedals, jimi"
jimi:" oh, baby, you know, just finishing up this last one for now...."



a week goes by...girl remains strangely silent, googling realtors and job listings...

jimi" hang on baby, i'm almost done...."   

[pinkjimiphoton]

ok....finally SUCCESS!!!!!!!!!!!!!!!!!!!!

the schem above works, but has some mistakes....

like.....the diode feeding q2's bass needs the stripe facing the base, not the cap....reverse it, and the circuit is dead..

the attack and volume controls are backwards, as shown. should be an easy fix.

when all's said and done, i used an nec103a ge for q1, a 2n3904 for q2, ans a 2n5088 for q3.

after i convert the breadboard to a vero, i'll do a CORRECT layout and up it.

thanks for all the help guys!!!!!!!!!

maad props to you, and you, and you....and the whole forum, from aaron and rg on down the line...

peace,
jimi

[K Zustang]

SO....how's the sound from this layout?

....trying to figure out which way to go. your way of the Hot Silicon way. bot seem pretty descent. HS has a more elaborate tone control. might try it with 2N2369 as someone pointed out for less bigmuffy tone.
I am looking for that sweet sweet undescribable fuzz and have built about 12 fuzzes so far of various kinds but still the sweetness eludes me.
The sweetest so far are The Maestro FZ-1, AstroTone and the Ge FuzzFAce, for me, anyway,
cheers

Zustang

[pinkjimiphoton]

here ya go....not big muffy, not fuzz-facey...got it's own sound. depends on what ya like.

doesn't sound like a silicon fuzz, the germanium helps. it sounds like a hybrid, tried to get the best of both worlds.

[Gus]

Have you looked at this?

http://www.aronnelson.com/gallery/main.php/v/DougH/fuzz/hotsi/GS_Tonebender.gif.html

[pinkjimiphoton]

yah, it's yet another variant, similar to the one i built. i take no credit for my version, it's based on several different versions and a lot of time playing with different parts to come up with something i liked.

[pinkjimiphoton]

i upped my working/verified version on the forum, i call it the toneblaster.

http://www.diystompboxes.com/smfforum/index.php?topic=91277.0

[blooze_man]

I just breadboarded this yesterday and it sounded great. Used a 2n2222 for Q1 and BC108's for Q2, Q3.

http://www.generalguitargadgets.com/diagrams/tonebender_m2p_sc_ns.gif?phpMyAdmin=78482479fd7e7fc3768044a841b3e85a