Nein Fuzz 3rd Attempt/Failure

[Depattern]

this is probably a lost cause since im not skilled enough to properly troubleshoot. I have a multimeter but aside from basic voltage and continuity testing, i dont really know what im doing but i wanted to give it a shot after buying the pcb and jfets 3 separate times.

i thought i accounted for the dumb obvious mistakes in my first two builds (soldering the wrong component or pad, then severely botching the desoldering - im really bad at desoldering), and i felt like i did everything according to the instructions i had here. im 95% sure i didnt use any incorrect components like 470k vs 470r, and r2 is 47k. everything is oriented properly. q2 is only soldered like that because i was trying to get ai to help me and it wanted to me swap that jfet for another one due to the weird drain voltages:


but i think the orientation is correct (d,s,g from left to right when facing the top of the pcb). and the pins are soldered on the top and bottom. I know my soldering is shotty but the continuity tests ive done dont show any obvious issues


this is what i have so far:

• Q1 D: 8.06V
• Q2 D: 8.93V
• Q3 D: 1.248V
• Q4 collector: 3.9V
• Supply: 9.41V
• All carrier orientations verified (potentially)
• All resistors measured correctly (mostly)

powers on, led comes on with the switch but no audio when engaged. i get my clean guitar signal when switch is bypassed. sometimes i hear a tiny bit of scratchiness when turning the vol in pot (much moreso in my last build attempt), but really almost completely silent. one thing im kind of unsure of is the in/out jack soldering, which should be the most basic aspect of a build like this, but i guess that since im getting the clean bypassed signal its ok? i dont even know if thats true or helpful. i was thinking maybe its something simple like the ground points arent all connected, or the jfets arent making proper contact, but i've had the same issue when i soldered the smd jfets (non-pre-soldered) directly to the pcb pretty successfully.

I don't know if this is enough info for direct troubleshooting but im wondering if anything glaring sticks out, maybe even the poor soldering? although i have reflowed almost every single point that was even slightly dull but there are some bigger blobs remaining which ive attempted to re-do a few times. the jacks and power connections especially are bad due to the twisted awg wire, but those dont seem to be the issue as far as i can tell(?)

i used film caps for the first 2, then i bought a bulk box film cap pack for this one. i had some others on order from stompbox parts but they didnt arrive in time for this one. thats what the yellow 100n (104 100v) and 10n (103 100v) are

maybe someone as unskilled shouldn't be attempting this but i would really love to give this pedal a shot and i feel that it would be so much more satisfying that just buying another pre-built fuzz, even though i may unfortunately end up with no choice. it seems like a really rewarding pedal to build: the kind of overdriven tones, the unruly gnarly timbres, the chaotic biasing.

so really, any general troubleshooting or any ideas at all that maybe you would try yourself if you werent sure why a pedal build isnt working would be very helpful. claude ai usually does not steer me wrong but its been sending me down some mind numbing rabbit holes that arent helping with these builds at all



kind of a sentimental thing, as i had the genius idea of dedicating it to my dog who passed recently. so feels extra depressing to leave it broken

 

[Depattern]

Successful CARCASS build. I’m on a roll!

 

[andare]

Build #5 complete. Worked perfectly immediately, only took about 2 hours start to finish. I can almost do these nein fuzzes in my sleep at this point

View attachment 116704

Sounds the same as the last one, which gives me confirmation that they are functioning as they should. Love the sound of these pedals, very “ripped” character, I finally understand what the “Velcro” adjective means and I love it

Next, I have the Carcass (carcosa fuzz), Shika (hizumitas), Referee (broughton resonant filter eq) pcbs and components arriving in the next 2 days. So I think I’m starting them in that order once I have some free time to dedicate to the builds

Can't read the whole thread now so I'm gonna ask: do you just use any JFETs in the Nein and they all work?

 

[Band of Dans]

Missed this thread earlier but just wanted to say congrats on getting it working and finding a technique that works for you! This reads so much like my experience on my first few non-kit PCBs it’s scary . Trashed boards, lifted traces from desoldering, cold joints and finally building my first audio probe.

I recently mama-bird’ed a couple friends through their first pedal projects and was really glad to be able to catch them making the same mistakes before they became a hobby-ruining ordeal. We even broke out the ol audio probe and found a lifted trace, ha!

I know you already have tons of advice to follow but my one contribution is this: whenever your troubleshooting process moves beyond the level of visual inspection, just desolder that power jack and take everything out of the enclosure. It’s always worth the effort, even if you have to redo the wiring.

 

[Depattern]

Can't read the whole thread now so I'm gonna ask: do you just use any JFETs in the Nein and they all work?

Yeah in my experience, especially the pre-soldered jfets from pedalpcb work great. The three I built successfully, especially the last two with no issues sound just about identical

 

[Depattern]

Missed this thread earlier but just wanted to say congrats on getting it working and finding a technique that works for you! This reads so much like my experience on my first few non-kit PCBs it’s scary . Trashed boards, lifted traces from desoldering, cold joints and finally building my first audio probe.

I recently mama-bird’ed a couple friends through their first pedal projects and was really glad to be able to catch them making the same mistakes before they became a hobby-ruining ordeal. We even broke out the ol audio probe and found a lifted trace, ha!

I know you already have tons of advice to follow but my one contribution is this: whenever your troubleshooting process moves beyond the level of visual inspection, just desolder that power jack and take everything out of the enclosure. It’s always worth the effort, even if you have to redo the wiring.

That’s good advice. I try to do everything in my power to not have to lift that board out once I finally set the knobs and switches in place and get that led glued into the bezel

The biggest tips and helpful improvements were keeping my solder iron at max heat, using tip timber when needed, FLUX PEN is absolutely necessary and I don’t know why I didn’t know that before entering this forum (the beginners guide here is very helpful as well), the audio probe, and solder tip usage/proper technique. I’m sure I’m forgetting some as well, but this thread has single-handedly made me a competent diy-er finally after years of weak misguided attempts with diy monome stuff, ciat lonbarde builds, mods, etc

I really appreciate the people in here

 

[andare]

That’s good advice. I try to do everything in my power to not have to lift that board out once I finally set the knobs and switches in place and get that led glued into the bezel

The biggest tips and helpful improvements were keeping my solder iron at max heat, using tip timber when needed, FLUX PEN is absolutely necessary and I don’t know why I didn’t know that before entering this forum (the beginners guide here is very helpful as well), the audio probe, and solder tip usage/proper technique. I’m sure I’m forgetting some as well, but this thread has single-handedly made me a competent diy-er finally after years of weak misguided attempts with diy monome stuff, ciat lonbarde builds, mods, etc

I really appreciate the people in here

Iron at max heat is not a good idea IMO. Too easy to burn pads and wear out tips too fast.
An iron that has good recovery and holds temperature, however, like a T12 or 245, is a very good idea. You can always crank the temperature for large components and turrets but for pedal PCBs I like 350 degrees.

 

[Depattern]

Iron at max heat is not a good idea IMO. Too easy to burn pads and wear out tips too fast.
An iron that has good recovery and holds temperature, however, like a T12 or 245, is a very good idea. You can always crank the temperature for large components and turrets but for pedal PCBs I like 350 degrees.

That’s a good point, I should have specified for my Fanttik T1 which I believe is very low wattage (16, iirc) and i keep it at 840f. So it’s not general advice or maybe not even the best option for me but I know it works better than any other temp I’ve tried before. Although maybe I don’t have to go overboard now that I always use the flux pen on literally everything

But I can say that at 840 degrees with a flux pen and this HGMZZQ 60/40 Tin Lead Solder Wire with Rosin core for Electrical Soldering 0.031 inch(0.8mm-50g) & my Type-SI iron tip, soldering is a thousand times easier and faster. I have had zero issues for the most part

Also that MG Chemicals 426-NS #4 No Clean Super Wick Desoldering Braid is the first desoldering braid that has ever worked at all for me. It’s weird, it feels like such a massive disparity between bad tools being so terrible and the right tools being so perfect that it’s night and day, with little middle ground

I should mention though because someone said elsewhere that I did have an issue with the Carcass fuzz led. Not sure if I managed to fry something or what, but I had to put a 4.7k resistor between the led anode, soldering it to the positive power supply pin, then solder the cathode to the “sw” contact on my 3pdt footswitch breakout board to get the led workint

 

[andare]

That’s a good point, I should have specified for my Fanttik T1 which I believe is very low wattage (16, iirc) and i keep it at 840f. So it’s not general advice or maybe not even the best option for me but I know it works better than any other temp I’ve tried before. Although maybe I don’t have to go overboard now that I always use the flux pen on literally everything

But I can say that at 840 degrees with a flux pen and this HGMZZQ 60/40 Tin Lead Solder Wire with Rosin core for Electrical Soldering 0.031 inch(0.8mm-50g) & my Type-SI iron tip, soldering is a thousand times easier and faster. I have had zero issues for the most part

Also that MG Chemicals 426-NS #4 No Clean Super Wick Desoldering Braid is the first desoldering braid that has ever worked at all for me. It’s weird, it feels like such a massive disparity between bad tools being so terrible and the right tools being so perfect that it’s night and day, with little middle ground

I should mention though because someone said elsewhere that I did have an issue with the Carcass fuzz led. Not sure if I managed to fry something or what, but I had to put a 4.7k resistor between the led anode, soldering it to the positive power supply pin, then solder the cathode to the “sw” contact on my 3pdt footswitch breakout board to get the led workint

I have never used a flux pen. A good iron with a freshly tinned tip works every time for me.
I started out with a crappy iron that would take 5 minutes to get to temp and would cool down after every joint and I botched a lot of joints.
Getting a better iron has been a game changer

 

[Depattern]

I have never used a flux pen. A good iron with a freshly tinned tip works every time for me.
I started out with a crappy iron that would take 5 minutes to get to temp and would cool down after every joint and I botched a lot of joints.
Getting a better iron has been a game changer

I started off years ago with one of those cheap $11 ones with the cable attached to the end and no station/cradle, and I thought I was terrible until I got a weller. I got the Fanttik maybe 6 months ago because I would go through tips very quickly on the weller but I bet if I were to use that again now it would be a much better experience

I like the little Fanttik though. I did just learn that it was excessively low wattage though, so maybe I’ll upgrade at some point. Works great for now though