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It sounds like the preamp & output portions of the circuit are working OK, so that leaves either the Gate, BBD, or modulation sections. The first thing you'll need to do is to make absolutely sure you have the Gate & Bias trimpots set properly. Unfortunately, they both have quite narrow usable...

At first glance it looks like the 741 opamp is acting as an integrator, which uses a gate or trigger signal from the pushbutton to create a ramped output. R2 & R3 likely change the RC time constant for different envelope characteristics, and it looks like R4 is possibly a threshold control for...

My mind must have been in the clouds when I was writing that, because I 100% mixed up my °C and °F... My iron is in Celsius and is set to 350°C (662°F), and that's for 63/37 eutectic solder (with a lower MP of 183°C/361°F). Now that I re-read pcborpcp's comment, 572°F (300°C) is DEFINITELY too...

Sn60/Pb40 solder melts around 361-370°F, so your iron may be set too high for that particular solder. That said, the soldering iron set point for a particular solder is usually higher than the melting point anyway, and is highly dependent on the power rating (in Watts) of your soldering iron and...

Good to know about the ground planes. I think I'm just used to any joints that have a hint of haze or texture being sub-par with leaded solder. Our shop recently upgraded from 1990s Metcal induction stations to modern Hakko FX-951 resistive ones and it's been a big improvement. We don't do...

I use lead-based solder at home for simplicity, but we use 99C or K100LD (Kester's proprietary version) at work and it's decent enough. Coming from lead-based, I'm never that impressed by the finish on my lead-free joints. Any tips on working with high-Sn content alloys?

What is the Sn/Pb percentage?

What type of solder are you using?

I used to have similar problems with 60/40 solder, but have switched over to 63/37 eutectic and it's SOOO much easier! I prefer 0.031" Kester 44 Sn63Pb37 with 3.3% flux content (part number 24-6337-0027). Most solder alloys melt and solidify across a temperature range, which for 60/40 is...

Just as a heads up, you may want to turn your soldering iron temp up a bit, that will help the solder flow more easily & give you smoother, more "domed" pad joints. There are lots of leads on the component (top) side of the board where the solder hasn't flowed through, which often means the temp...

No worries man, I know your pain! Those photos are a LOT better. The red circles are potential short circuits, and the yellow ones are solder joints that may or may not be completely soldered (may need to touch them up). I would also go back and clip any leads that are poking out, especially...

I'd do the same at both pads of C39, 40, & 41 as that will help us identify if they are the problem. For electrolytic caps, the the square pad is the (+) side and the round pad is the (-) pad side. You should get a beep (or close to 0 ohms) on the (-) pads as they are connected to ground. On the...

I built the LT as well, and it's a complex build to troubleshoot, but well worth the effort. Here is the schematic, which is a critical reference during troubleshooting. Without being able to power up the unit, you'll mostly be looking to find connectivity (the beep setting on your DMM) between...

It's a PCB, designed in Inkscape and exported to Kicad via SVG2SHENZHEN

The basic range of the Randomizer control voltage will be set by the code within the EEPROM, which is further limited by it's 0-5V rails. Unless you want to flash your own EEPROM, you're better off playing with the circuitry after the EEPROM. The Depth control obviously attenuates the control...

It's defo below 5Vp-p as it's running off +5V and 0V (GND) rails. Taking a peek at the voltages I took during troubleshooting, mine were mostly between 0V & 2V, so ~2Vp-p. Mind if I ask why you're looking for this specific control voltage range?

Just for reference, this is likely the non-conductive grease used for lubrication of mechanical & electrical surfaces. It will also prevent intrusion of dust/dirt into the interior of the potentiometer, so it's likely best left alone. If you really want to remove the residue, I would avoid...

I've experienced this sticky residue with Alpha pots to a small degree, but the Tayda pots are absolutely covered in it! I haven't tried cleaning them before install and I haven't noticed any differences in performance or dirt magnetism. It's about as bad to get off your hands as flux though...

That's just a general range, but different circuits will play better/sound different with different values, and the Fuzz Face is fine with higher leakage transistors.

I've had a few issues with untraceable short circuits in 3PDT boards, especially with cheap 3PDT switches. Is there a trick to preventing that when soldering them?