Author Topic: Tweak-O, uh, improvements... (Also, hi everybody)  (Read 1907 times)

robidor

Tweak-O, uh, improvements... (Also, hi everybody)
« on: September 18, 2007, 06:46:25 PM »
Hi everybody, my name's Chris.  Or you could call me rob.

I'm new to this whole stompbox-making thing, and am only posting this because I've been lurking here long enough to know you guys are pretty patient with newcomers to the board and to the trade.

So last weekend I built me a Tweak-O.  Debugged it and everything, and it works!  I learned a lot from that, too.  But now that I have a working Tweak-O, I'm noticing that I only really like the sound of it when the fuzz and level pots are dimed.  Anything less doesn't sound CLOSE to harsh enough.  It's so...meh...  But I guess that's why Steve layed out the board the way he did.  Plenty of room to mod.  Which is what I intend to do.  Which is why I'm posting.

I found that big muff tone loop mod in the "simple mods" part of the wiki, and it immediately peaked my interest.  I printed out a fresh copy of the schem and worked it in there (just jam it between C7 and R7, right?).  Also, I read elsewhere about tossing some extra diodes in to fuzz out the tone loop.  I like the sound of that, I wanna try it with the Tweak-O.

And one more thing.  I think I just want to keep the fuzz permanently dimed.  I'm not gonna use this thing as a flat boost, I just want it to make murderous distortion.  Can I remove the 250K "fuzz" pot and just put a 250K resistor in its place without messing up the biasing?  Or am I way off track?

And if I'm way off track... Well, after these mods, is this thing going to sound like hell?  I mean in a good way.  I want horrible, horrible noise.  But in a rock 'n roll kind of way.  Would I be better off starting a new pedal?  Thanks, y'all.
MMXII

Boxes completed:  Tweak-O, Stratoblaster, Fuzz Face, RM Octavia
Boxes ruined:  Tweak-O
Boxes modded:  Ibanez DS7, Boss BD3, Fuzz Face
On the bench:  LPB/FF

robidor

Re: Tweak-O, uh, improvements... (Also, hi everybody)
« Reply #1 on: September 19, 2007, 01:17:24 AM »

quick schem, right before the volume pot in the Tweak-O.  Sorry about the camera phone...best I can do right now.
MMXII

Boxes completed:  Tweak-O, Stratoblaster, Fuzz Face, RM Octavia
Boxes ruined:  Tweak-O
Boxes modded:  Ibanez DS7, Boss BD3, Fuzz Face
On the bench:  LPB/FF

robidor

Re: Tweak-O, uh, improvements... (Also, hi everybody)
« Reply #2 on: September 19, 2007, 06:30:13 PM »
Last try at a bump.  Perhaps not as much patience for the newbies as I was expecting... Serves me right, I guess.  I should figure this stuff out for myself.
MMXII

Boxes completed:  Tweak-O, Stratoblaster, Fuzz Face, RM Octavia
Boxes ruined:  Tweak-O
Boxes modded:  Ibanez DS7, Boss BD3, Fuzz Face
On the bench:  LPB/FF

Somicide

Re: Tweak-O, uh, improvements... (Also, hi everybody)
« Reply #3 on: September 19, 2007, 06:39:32 PM »
don't be discouraged if nobody responds immediately; this thread has only been up a day now.  I personally am not familiar with the Tweak-O, but some gurus should stop by shortly.
Peace 'n Love

Paul Perry (Frostwave)

Re: Tweak-O, uh, improvements... (Also, hi everybody)
« Reply #4 on: September 20, 2007, 12:14:46 AM »
And one more thing.  I think I just want to keep the fuzz permanently dimed.  I'm not gonna use this thing as a flat boost, I just want it to make murderous distortion.  Can I remove the 250K "fuzz" pot and just put a 250K resistor in its place without messing up the biasing?
Sure, you can always replace a 250K pot by two resistors that add to the same total, or if (as in this case) the pot is wired as a variable resistor, you can replace it by any resistance from 0 to 250K. Even better possibly, a trimpot inside the box, so you can do the screwdriver adjust if you ever want to.

robidor

Re: Tweak-O, uh, improvements... (Also, hi everybody)
« Reply #5 on: September 20, 2007, 03:17:11 PM »
don't be discouraged if nobody responds immediately; this thread has only been up a day now.  I personally am not familiar with the Tweak-O, but some gurus should stop by shortly.
Yeah, sorry about that.  Bad day yesterday, I took it out on the internet.  It wasn't the internet's fault.  Not my intended first impression, whoops...

Sure, you can always replace a 250K pot by two resistors that add to the same total, or if (as in this case) the pot is wired as a variable resistor, you can replace it by any resistance from 0 to 250K. Even better possibly, a trimpot inside the box, so you can do the screwdriver adjust if you ever want to.
I read up some more.  I think I'm gonna try the trimpot.  Until it comes in the mail, I think I'm just gonna replace the 250K pot with NOTHING.  That oughtta sound cool.

I should be getting some quality workbench time in these next few days.  I'll post results on how the Big Muff tone thing sounds in here.  Or I'll post a question about how the bloody f!ck it's supposed to work.  This is actually my first shot at laying something out based only on a schem.  I breadboarded it yesterday, but didn't hook it up to anything.  I think I got the idea down...  I'll spare you the camera phone pictures this time.
« Last Edit: September 20, 2007, 03:21:10 PM by robidor »
MMXII

Boxes completed:  Tweak-O, Stratoblaster, Fuzz Face, RM Octavia
Boxes ruined:  Tweak-O
Boxes modded:  Ibanez DS7, Boss BD3, Fuzz Face
On the bench:  LPB/FF

bipedal

Re: Tweak-O, uh, improvements... (Also, hi everybody)
« Reply #6 on: September 20, 2007, 03:23:05 PM »
I started my building with a Tweako too.  Recently dug it out, dusted it off, and added an SWTC (stupidly wonderful tone control -- search the forum for details), and messed with the clipping diode arrangement.  I've now got a little red LED peeking out of the box that flickers as it clips (cool!).

It's now a bit less sizzly and has a bit more Marshall-ish growl compared to the original, which I like.  Sounds like you're interested in going the other way.

Throw some sockets in there to mess with the resistors and diodes and try a bunch of options out.  I've got a lot to learn about the theory behind this stuff, but my ears provide great info about whether a tweak works or not.   ;)
« Last Edit: September 20, 2007, 03:24:36 PM by bipedal »
"I have gotten a lot of results. I know several thousand things that won't work." -T. Edison
The Happy Household; The Young Flyers; Derailleur

robidor

Re: Tweak-O, uh, improvements... (Also, hi everybody)
« Reply #7 on: September 20, 2007, 06:02:24 PM »
Yeah, I think I'm just going to try to go monkeysh!t inside there.  I've got a bunch of different silicon diodes, some LEDs.  Ordered 16 Ge ones from Aron, I sure hope they get here soon.  I'm gonna try to mis-match pretty much every diode pair (or trio, where I feel like putting two on one side of a parallel diode arrangement).  I read about that SWTC thing, and it does sound pretty nice.  But I've put too much time into the Muff-y mid-scoop to turn it around now.  I want this thing to DESTROY my guitar signal.  I think I might call the finished product Tweakermuff, since I want it to feel like the inside of a nasty meth-head.  Oh God, it'll be horrible... :icon_twisted:
MMXII

Boxes completed:  Tweak-O, Stratoblaster, Fuzz Face, RM Octavia
Boxes ruined:  Tweak-O
Boxes modded:  Ibanez DS7, Boss BD3, Fuzz Face
On the bench:  LPB/FF

robidor

Re: Tweak-O, uh, improvements... (Also, hi everybody)
« Reply #8 on: October 01, 2007, 08:16:33 PM »
I finished this probably two weeks ago, but I just now remembered I said I'd post results.

Well, the results were crap.  I mean, if I put a guitar in one end, noise would come out the other.  So I built it right, it worked.  But holy crap, it was awful!  Horrible in a bad way.  Buzzy, farty, too quiet...  I shoudla known better.  Stupidest sounding pedal I've ever heard.  Uniquely stupid, I guess... Never heard anything that sounded like THAT kind of crap.  But crap's crap.  Maybe I should learn more before I come up with any more bright ideas...

On the bench now: 
My MIM 72 reissue custom tele.  Swapped the pots out for 500k.  Tried to star ground it, but I think I missed a step.  I'll be going back in there tonight. 
Also, did a lazy Keeley mod my buddy's Blues Driver (didn't swap out the ceramic caps for silver mica, just changed the values he listed on his website).  I probably did a B+ job on that one, it's a little hummy.  But only a little.
I changed the clipping diodes in my Ibanez DS7 to Ge 1N34A's from the store here.  That sounds nice, too.  Bumped the output cap up to .1uF, it sounds reeeal ugly.  But I can live with that kind of ugly.  Anyone have any better ideas for something to do to this totally boring pedal (that I got for my 16th birthday 9 years ago)?  Haven't been able to find anything in my myriad searching.  Probably too boring to mod.  Nice and gainy, though.
Oh, and I built a Stratoblaster for my friend, too.  Put it in a plastic enclosure from Radio Shack.

In the mail:
I'm gonna get my big-boy on and make a Fuzz Face with the Roger Mayer/Jimi Hendrix mods listed on GEOFEX.  Though something tells me I should use the resistor values listed with the trannies I got from Small Bear.  It would be dumb to ignore that, right?
Also, I'm gonna makes me an opamp BMP using Gila's Vero layout.
And after that, perhaps a Ross compressor?

I think this pedal thing is turning from an interest into a hobby.  Probably on its way to obsession.
Anybody have any advice for a wet-behind-the-ears chump who thinks he can do anything?
MMXII

Boxes completed:  Tweak-O, Stratoblaster, Fuzz Face, RM Octavia
Boxes ruined:  Tweak-O
Boxes modded:  Ibanez DS7, Boss BD3, Fuzz Face
On the bench:  LPB/FF

caress

Re: Tweak-O, uh, improvements... (Also, hi everybody)
« Reply #9 on: October 01, 2007, 09:36:06 PM »
you might want to use an audio probe and check out the sound before the tone portion that you added.  if it has ample volume at that point but is quiet after, you might consider adding on a simple recovery stage after the tone portion - you can just use the one from the bmp.  that tonestack eats a bit of signal...

also, you might want to consider building the tweak-o again on a breadboard.  that way you can make it stock and see what it sounds like in its unadulterated form, then mod it to taste.  that way you can really see how your modifications are effecting the sound.

and yeah, you should probably go with the resistor values listed with the smallbear trannies for the "best" sound.

robidor

Re: Tweak-O, uh, improvements... (Also, hi everybody)
« Reply #10 on: October 02, 2007, 04:11:45 PM »
Eh, I've already started cannibalising the Tweak-O for parts.  I ruined it.  Though I have been meaning to get an audio probe together.  Heh, maybe I'll use one of the caps off the Tweak-O to make one.

I'm gonna take what I've learned (NOT to do) and carry it on to the FF.  And I think I'll get a little trimmy in there with the resistors.  Nobody on here seems to have ever thought that was a bad idea...
MMXII

Boxes completed:  Tweak-O, Stratoblaster, Fuzz Face, RM Octavia
Boxes ruined:  Tweak-O
Boxes modded:  Ibanez DS7, Boss BD3, Fuzz Face
On the bench:  LPB/FF