freestompboxes.org

it's a mod I did to the mini booster that was called the Fat Boostered on the GGG site. I called it the Fat Bastard (it was when Austin powers 2 came out that i did it), but GGG changed the name when they posted the schematic. Paul C

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This is one of favorites among the booster circuits!
Extremely versatile and sounds real good!

Layout; Correction by PaulC: C3 should be 33nF or 0.033uF; JFETs 2N5457 Transfer; --------------------------------

how do i convert that to vero? I would love to try out that circuit

polarbearfx wrote:how do i convert that to vero? I would love to try out that circuit

I've never seen a vero of this anywhere.
You don't etch huh?

years ago I made an attempt, I am a newbie for the last 3 years. I failed and the stuff was so toxic it kind of freaked me out. I understand it all but at the same time don't. You could say I am a slow learner, but the vero I understand its easy. Perf I would love to figure out better as I can only handle simple things on perf, PCB I am good with as long as I don't have to make em

PBFX you can use Bancika's DIY Layout Creator to do a Vero from the Schematic. Here's one GillesC did
http://www.gtechblues.com/Projects/Fat_Boostered.pdf

I haven't verified this, I did a PCB from the GGG layout for mine. Great sounds.

superpuma thanks for posting that, i am not quite sure i understand it. I imagine the x's are for cuts, but what are the red squares with the blue arrows inside? and how would i hook up the J201's? seems strange. It might be totally legit but my understanding is coming up short.

you can snag the vero here:
http://www.indyguitarist.com/torchy/Boo ... stered.GIF

polarbearfx wrote:superpuma thanks for posting that, i am not quite sure i understand it. I imagine the x's are for cuts, but what are the red squares with the blue arrows inside? and how would i hook up the J201's? seems strange. It might be totally legit but my understanding is coming up short.

Have a look at page 3 of that PDF, the arrows are transistor socket (4 for each Q) to accomodate for different fet pinouts.



Built this circuit I think three times, and immediately went for 2N5457 fets. I've built some other boosters (one transitor type) and even a TS-based opamp booster would have a hard time competing to this.

Fat Bastard Paul Cochrane - "Try it infront of a sweet thing... Also going with the 100 ohm source let's you get a little bit of hair when crankin' the gain, but you can still get a huge flat/clean boost when you set it down"
https://www.diystompboxes.com/pedals/schematics.html

This may be true, but what I do is put volume down, gain almost maxxed out.

Just for the record this was something I gave to aron many years ago for fun. Everybody and their grandma was playing around with the srpp stage, and I dinked with it, and gave it to aron. i never asked for it to have my name stuck on it. It was just my mods to jacks modded circuit I did for fun.

It'll work better if you put a buffer on the output, and sometimes I'll have a fet gain stage on the front DC coupled into that source follower. This will give it a little more gain if you need more hair. You can also change the bias tap to a filtered divider (like you see with the 4.5vdc supply with opamps) for a little less noise. A cool thing with that is it doesn't have to be 4.5vdc. You can offset if for some asym clipping from the srpp.

The name came about because it was back during Austin Powers 2 when I gave it to aron. Everybody was doing the "fat bastard" voice, and I like to name stuff after movie characters. There's another pedal that's produced called this, and some people thought there was an issue there. I know the guy that makes it, and we never had a problem. He didn't know it was out there, and i really didn't care since i don't make it for sale anyway - it was just for fun. As far as i know he's making something different. The only thing that was odd to me was why the name was changed when it was posted on GGG. I guess the name was to "harsh".

Have fun with it.

Later, PaulC
Heritage amps/Tim & timmy pedals

paulc wrote:Everybody and their grandma was playing around with the srpp stage, and I dinked with it,

Djeez Paul! You could'n have said that more accurate i remeber that time. Srpp was a The Way To Go for a while and everyone followed. Thanks for the reminder of a "back in the days" moment

What should the tone controls do? cut - boost? both? I recently build two of them and one only cuts ( full cw flat) the other boosts the low frequencies (full ccw flat) und cuts the highs. Both cut the highs not realy effective. I definetely made a mistake. Shouldn't the bass control be flat in middle position? That would make sense to me...

It's been years since i built this thing, and I never used the schematic GGG made, or the layout Mark put up. I guy just asked me some questions about a build not working right, and when i looked it up there's some errors on the posted stuff.

In the layout the cap going to the volume should be a 33nf, and not a 3.3nf. That will really pooch up how the bass control works. Also I used 2n5457 jfets, and not the j201's that are shown.

The pots i used were log, and not the lins posted.

Here's the original schematic i gave to Aron years ago. https://i58.photobucket.com/albums/g259 ... astard.jpg

Of course there's tons of things that can be done to it. For one that input buffer isn't really all that great. At the time i was in a kick to get rid of as many series caps as i could. It'll work better if you bias it up like you'd normally see input source/emitter followers done. in fact you could make the 1M/1M voltage divider used on the srpp stage a bias tap like you'd see with opamp circuit fake split rail pwr supplies, and use that for both the srpp, and to connect the gate/base of the input buffer (don't forget to add an input cap).

Better yet is an input stage like this one: https://i58.photobucket.com/albums/g259 ... /input.jpg

This will give you an input stage with a high input Z, a little gain, and a low output Z. I don't have parts values listed because it would depend on what you use. I'd try a 2n5457/MPSA18 to start.

Last time i built it I had a buffer on the output. Easy to do.

For all the guys that built this, and it didn't work right I'm sorry I didn't look hard at the posted schematics/layouts. The one above is what i gave aron.

Later, PaulC
myspace.com/paulcaudio

Thanks for the clearing words....

But I think it should read: 2N 5457 instead of 2n 4547 ?

analogguru

analogguru wrote:Thanks for the clearing words....

But I think it should read: 2N 5457 instead of 2n 4547 ?

analogguru

Yeah - you're right. Fingers typing faster than the brain... At least I got it right on the schematic

Funny - my whole point of this was to show value errors Mark and GGG had, and I type the wrong thing...

BTW - I can't find an "edit" button. Can posts not be fixed?

Thank you Paul!!

paulc wrote:

analogguru wrote:Thanks for the clearing words....

But I think it should read: 2N 5457 instead of 2n 4547 ?

analogguru

Yeah - you're right. Fingers typing faster than the brain... At least I got it right on the schematic

Funny - my whole point of this was to show value errors Mark and GGG had, and I type the wrong thing...

BTW - I can't find an "edit" button. Can posts not be fixed?

I think only one hour or so the post can be edited by the member - to avoid confusion. But the typing errors have been fixed now by the moderator.

analogguru

Of course there's tons of things that can be done to it. For one that input buffer isn't really all that great. At the time i was in a kick to get rid of as many series caps as i could.

Yeah, i see the "get rid of as many series caps as possible" and i think i prefer that no input coupling cap config when speakig tone wise. But what would you don't like on that aproach?

Paul - with the "2n5457/MPSA18" combo what values would you use?

This one has become my favourite booster pedal! Just love the double tone control.

Thanks paul and mark for the schematic and pcb layout.

Anyway i need help for a little improvement. How can i get more output volume?
When i use it as a cleaner boost i have to crank up the volume knob at max and still can't get enough volume increase. I am using j201.

sadrew wrote:Anyway i need help for a little improvement. How can i get more output volume?
When i use it as a cleaner boost i have to crank up the volume knob at max and still can't get enough volume increase. I am using j201.

When I built it from the schematic specified with J201s, I used sockets and tried different fets. Once I had put in the 2N5457s in I never looked back. The J201 seem to generate overdrive fast, and I've read reports of people using it as such.

I always use it with the gain cranked and the voume down - otherwise it's too loud, But if you are not getting beyond unity gain, there is a problem with your circuit. If you can get loud enough, but it doesn't stay clean, try 2N5457, 2n5458 or MPSA18 jfets.

good luck,
modman