First Perfboard Build: Fatpants

[HKimball]

So, earlier today I completed my fatpants build (just have to install the indicator LED) - I fired it up to see if everything was working and much to my chagrin it was. I had the buffer working since forever but only recently got the boost section functioning.

I know there's no good reason to use carbon comp resistors but I did anyway. When my 12v adapter comes in (already got an appropriate charge pump and internals to run at 23v btw) I will have this running at the full mccoy. If not for the zener diode it would work up to 15v (or 30v internally) but I'm going for as close to the echoplex as I can.

Instead of a TIS58 I used a MPF102 for Q1 - I've read that this is very close to the TIS58 and significantly cheaper so I went with it. Q2 is a standard J201 which I like very much.

It was kind of a pain to get everything working properly because I included a true bypass/buffer dpdt switch so I could hear the effect of the buffer a little better (and potentially use it in conjunction with my buffered pedals like my modded SD-1), but after studying the sunking build guide I was able to get everything working properly. The trickiest part was the "sw" part of the board (I copied the layout of the PCB onto perfboard because I'm not creative enough to design my own) but once I figured that out it was smooth sailing.

I still have to clean a few things up (the fat control isn't insulated very well so if I jostle it around I get jumps in volume and intermittent scratchiness) but overall I'm pretty much there in terms of the build.

I also used exclusively red wire so it was insane trying to get everything wired up. For my next few builds I will definitely do exactly the same thing because all I have is red wire and I don't want to spend money on more. But in a perfect world I would use different colored wire.

Hmmm

I don't have a demo video yet (and am hesitant to say when I will post one if I do at all) but you've all seen the youtube video of the fatpants in the 1590A enclosure. It sounds like that. I built mine in one of the tiwanese BB seconds enclosures that Small Bear sells. I'll post some pictures later so you all can see just how hideous and awful the inside of it looks - if you're squeamish or OCD I would just skip coming back to this thread once I post photos lol.

Really, really like this pedal though. Gorgeous clean sounds out of it and later on if I get some alone time I will report on how it sounds into a cranked 1974x baby will (18w marshall clone).

[lincolnic]

Congrats on the perf victory! Let's have some pictures when you get a chance.

Why was it to your chagrin when it worked, though? Should've been the opposite!

[HKimball]

One step forward, two steps back I'm afraid.

After taking this picture and putting everything back together I fired up the fat pants, only to have no sound whatsoever come out... Bypassed, Buffered, or with the effect on. Nada. When I was having problems with the footswitch (right before it died) I would at least get sound with the effect bypassed.

So whenever I get some free time (hopefully this weekend) I'm going to have to address where I think the problems are.

1. The footswitch
2. The DPDT buffered/bypass switch
3. The jacks themselves
4. Grounding problems
5. Broken Wires

etc.

Ugh. All I wanted in the whole wide world was to be able to close the pedal up and have it work but unfortunately it was not to be. This is why even the lowly fatpants was a bit ambitious for my first perfboard build. But such is life. When it was working it was my favorite pedal so at least I have that to motivate me to get it working again.

[midwayfair]

Don't panic. An audio probe is your friend!

[HKimball]

So, update. The problem was caused by the output jack - apparently I got solder on it and connected the two terminals, but everything else was okay.

I have a new problem - there's a pronounced treble rolloff when I turn the volume down (even more pronounced than on a guitar before you add a treble bypass cap/resistor). I imagine it's because I have the volume pot wired incorrectly? Right now I just leave the volume all the way up and use the fat control to adjust volume but that's hardly a perfect solution. Even with the fat all the way down the volume boost is pretty intense. At first I had it wired with the one outer lug to ground and the other to hot with the middle lug wired to the effect output, but before I got it working again I changed it back (middle lug to output, one to effect and the other to ground).

What I may end up doing is wire a treble bypass cap+resistor just so I can keep the volume below all the way up and have it not sound like I'm playing underwater.

Other than that small problem though the pedal works as advertised. Like taking a blanket off of your speakers - just comparing the T/B sound with the Buffered sound is really eye-opening. Honestly I kind of like the buffered sound more than the sound with the effect on - in the future (knowing what I know now) I may build another one of these and use a different Q2 than the J201. As a buffer/solo boost it's perfect for solo lines (what I previously used my heavily modified SD-1 for) - adds some mids and thickness according to your preference and really makes solo lines stand out.

Other than that I also have a few od/boost related builds on the way (8ball, Bacon Bits) so I should report again once I get all the parts for them (turns out I needed a few more caps that what I got from mouser).

Thank you all for the help and support.

[HKimball]

Okay, so I know you guys are tired of seeing this bumped up to the top of the heap and I promise this is the last one.

I finally got everything working - don't know what caused the volume pot treble roll off but after I uncrossed some wires coming from the fat control everything seems to be well sorted.

I can't tell if the body switch works - on either setting there's scratch from the fat control - but I don't care because the sound is amazing.

Seriously I can't even begin to explain how good this pedal sounds. I had today off so I had some time to fiddle around with it and every setting sounds good. From unity boost (which is actually only about 10-11 o'clock depending on where I have the fat control set) to pushing my little 18w combo over the top, this little guy is electricity underneath my fingers. My clean sound has never been so good and the distorted sound is deliciously complex and 3d. I can't say whether or not I like this + my amp's distortion better than my Mythical Overdrive (bought in a moment of weakness, if I had more time/diligence I would have gotten the Sunking II which I still might do) yet but this pedal is definitely staying on my board in one form or another. Still have to get a 12v adapter but for the time being this runs great off of 9v.

Thank you to everyone for your help and I look forwards to reporting on a bloviator build and a bacon bits build sometime in the coming weeks. Also an 8ball build and two other secret sauce builds for friends.

[selfdestroyer]

Glad you got it going.. We don't mind the bumps as long as a photo of the finished product is posted... show it off.

Cody