Some Thoughts on building the BYOC Ultimate Fuzz

[neil411]

Some Thoughts on building the BYOC Ultimate Fuzz

This is my first post after lurking here for a while, sucking up as much knowledge as I can. I figured that there was no good purpose in posting unless I had something to offer. Now that I have completed my first pedal, the BYOC Ultimate Fuzz, I thought I might offer some observations on the kit itself, the mods I made and the build in general.

I knew I had to have a germanium fuzz pedal after I heard Peter Stroud playing the AnalogMan NKT275 Sunface at the recent Premier Guitar Festival in Boston. My wife gave me a Big Muff Pi for Christmas last year (I love saying that to people, just to see their reaction.) But the NKT275 Sunface is a whole different animal.

I also knew I was way too cheap to pay AnalogMike 275 bucks. I've rebuilt engines, restored a couple of cars, built numerous guitars, etc., so building an electronic device certainly wasn't beyond my skill level, especially if it came in a kit, with instructions.

Another plus for the BYOC kit was the free "Confidence Booster" kit that first time buyers get. (I replaced the trim pot with an external pot, built that in about an hour, mounted it in a plastic case, and hooked it up to my little Fender FM15 DSP amp. It really helps the low volume problem in the Acoustic and Jazz settings for that amp.)

I also decided to make some modifications based on the mods at the Beavis Audio site. I added the switches for transistors, and the Bias Pot mod.

The following are some observations that I had:

1. Overall the kit was a great first time project, the instructions were clear, the parts were all there, and it worked as advertised.

2. I did have some trouble which I think is due to the very small soldering pads on the PCB that is supplied with the kit. When I first turned the pedal on, I only had sound out of one of the transistor pairs, the other pair would not work at all. I tried an number of things before I had the thought that maybe I had a cold solder joint on the PCB. I simple touched my soldering iron to each pad and let the solder melt. They all looked fine, but the solder pads are so small that it would have been nearly impossible to see a cold joint.  re-melting all the solder joints on the PCB fixed the problem. I did not bother to find the bad joint, I just hit each one with the iron again. I would recommend that to anyone who buys any of the BYOC kits.

3. A note to anyone who wants to do the Bias Pot mod for this kit - The instructions call the trim pot a "10 trim pot" (that is NOT a typo, it is what the instructions call it.)  The Beavis Audio modifications call for replacing that trim pot with a 10k linear pot. Both are wrong. The trim pot is actually a 100k value pot. Replacing it with a 10k pot simply does not work well. Use a 100k or 200k linear pot. I used a B100K Alpha pot and it works great.

4. I did not use the included plastic mounts to mount the PCB. They used up too much space with all the mods I wanted to do. The kit is a tight fit as it is, and adding a small piece of perf board with transistor sockets, three mini switches and a full size pot didn't help. It all fits, but it's tight. You might want to consider getting a larger enclosure if you decide to add any mods to this kit.

5. In the end, I got EXACTLY what I wanted. I am still in "PLAY" mode, trying different combinations of transistor. The kit trannies work fine, I liked the BC109 in Q1 and AC127 in Q2 best. Right now I am running two OC140's and that sounds great too, a little darker than the silicon/germanium combo.

Now I am gathering the parts to build one of Aron Nelson's "Shaka Tube" pedals.

Then maybe a Uni-Vibe...

[foxfire]

i started with their tone bender. followed by the phaser and beaver. i have a tendency to rush things and, if i recall correctly any/all problems that i had were because of my rushing. i haven't gotten kits from anywhere else so i can't say byoc's are any better or worse. what i can say is that it's because of those first three pedals worked so well that i'm now totally hooked on this stuff. so much so that i dream about it from time to time. god, i am a dork. anyway that was a nice build report, congrats.

[neil411]

Thanks, yeah, I'm hooked too.

And my wife says I'm a doofus.

[foxfire]

well my girlfriend is actually my fiancee. so when she becomes my wife will i to become a doofus? i'm not sure but doofus sounds a bit nicer than dork? as it happens i just took up knitting but, i think pedal'n will still be my number one hobby.

[drewl]

Huh huh Big Muff huh huh....I have a big Muff T-shirt.....it always gets a reaction.