Forum dedicated to helping people debug and troubleshoot non-functional pedals or builds. Please use an clear and informative title, indicating circuit and basic problem. Don't forget to mark the issue as fixed if this is the case.
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Debugging 101 General rules and hints to succesfuly bring back that old pedal to life
I have an old Type P210 tc scf. The gain pot went open and I had to tear it apart to clean and lube the pot. All that done, I did some scoping and measuring and found that it's putting a DC offset at the outputs. The offset starts at 7V (roughly half of 15V) and decreases very slowly. I replaced the most obvious cap and that didn't help. Even when unplugged with a shorted input, it takes about an hour to get back to 0.0V.
The schematics are difficult to read, however, it appears that the...
Hello,
I want to revive my Big Jam SE-5 flanger pedal. It uses the SAD512d (8-pin chip, different from the original SAD512) delay line, and it appears that's the component that's gone faulty in my unit. It seems these chips are commonly failing now, and unfortunately appear to be rare and expensive when they do work.
I've seen that the R5106 was a drop-in replacement chip back in the day, but even those are scarce now.
But I've also heard that the RD5106ANP should work (though the datasheets...
Hi guys, i have here a musikding Engineering thumbs Compressor kit that is not working!
Schematic:
Guts Shot
Since i’m not the one who mounted the kit, i checked every component polarity etc. resolder a bunch of holes, and identified a wrong transistor in the circuit. It was with a BC337 instead of a BC327.
I changed the transistor, but its somehing else wrong.
I have bypass sound. When its on, seems like there’s no effect applied. Level pot its working , the other ones i can’t notice...
I built the Aion P2 (Cygnus) it sounds very good but it is extremely noisy when the volume and sustain control are high (no hum but white noise hiss).
I have already tried several transistors and double checked the wiring and soldering.
Is it normal for the P2 to be so noisy?
Hey,
Just completed a 'Hundo' TA-100 clone on a board from Effects Layouts; using 1N34As and MP42B pnps with HFe tested around 80.
It sounds great *IF* I touch the case of Q2, otherwise it sounds quiet, farty and terrible. It isn't an intermittent issue, just works if I touch it. The other issue was the volume did not work unless I grounded pin 1. I reflowed the Q2 and vol pads but the issues persist.
I just picked up this awesome stand alone reverb unit but it doesn’t really work. I’m hoping you guys can help out, might be of interest to somebody.
The unit passes dry guitar just fine, sounds fantastic in fact. I can only get a very weak wet output with the Gain, Blend, and Tone maxed out and hitting the input hard. Hoping for and easy fix I replaced Q5 & Q6 since I heard those two can go bad but there’s no change in operation. I also added C9 since it looked like it had been removed and...
I wanted to be able to use the power plug instead of the battery, but the power jack wasn't working. These have a plug style that looks like a headphone plug. I opened it up, made some very minor changes to the power wiring and now that power jack works.
Fast forward a few months and one day my PDS 1700 makes no sound. I try battery power, and plug power, and I desperately try and remember exactly what I changed with the wiring. I don't remember what I did. I have...
unfortunately i have a problem with my aion oceanid build. I built the pedal exactly as described in the documentation except for two capacitors C7 + C18. I substituted these with “Styroflex” capacitors of the same value. (This shouldn`t make any difference?).
The pedal works as it should except for there is amplification with all knobs on zero (so the signal is louder when the pedal is turned on). As far as I can tell all the other functions are working therefore there is an increase...
Unfortunately the Empire Big Joe Stompbox of the guitarist from our band is broken.
He took this pedal over from another musician years ago in good condition, so I suspect no guarantee and since we come from the Netherlands, having it repaired will be an expensive affair.
I have some experience in electronics, and can handle smd components.
I made a video of the problem, would you like to view this? Perhaps you can explain what is wrong with the device and give advice how...
Symptoms are that the LFO is not oscillating, so the right-hand LED is not flashing - it's on solidly.
Here's the schematic for reference:
I'm not seeing the triangle or sine wave forms on the output of op-amp IC-4b, instead I measure 14v DC. I've removed the chip and put a socket in so I can test alternate chips. Even without the chip in place I see 8v on pin 7, dropping to 2.8V when I adjust the vibrato rate control.
Hi, I have a walrus audio aetos power supply that operates at 230v. Would it be possible to modify or install a new transformer so the power supply operates off of a 120v circuit?
Any recommendations on where to start?
I’ve built a few pedals and an amp from a kit so I have some basic electronics knowledge.
Built RG Keen's Lera from Geofex to add to a PedalPCB clone of the Walrus Julia.
The On/Off switch works and the Lera does affect the sound of the Julia by adding a warble. The speed is quite fast. Neither the ramp up/down switch, the instant/delayed switch, nor any of the three trimpots have any effect on the sound.
I added the optional 10uF capacitor to the output of the 78L05 but no difference to the sound.
The build doc says Once you get it wired up, check it out with a...
Not quite sure how to explain what I'm asking for, but I think it's a Spectrum Analyzer. I have a state variable filter I built and would like to physically see how it's affecting my audio, like with frequency sweeps with the filter. Would something like work so I can plug my bass in, hit a note while playing with the frequency controls and see how the filter is affecting the signal in real time?
I have a beloved Boss ME 10 that's giving me some serious problems now.
It's extremely noisy now. Lots of white noise drowning out everything else. There is also a loud crunch/popping sounds every 10 seconds or so. The effects are applied to the noise e.g. if I turn on the delay, the static/white and crunch/pop noise will have a delay to it.
I thoroughly cleaned the board with contact cleaner and a new toothbrush and replaced the 7 caps. It almost seems worse after replacing the caps? I'm not...
Sorry im new and desperate without my FuzzFace. Its modified with 3 extra dials - 2 tone and 1 bias. And there is no power input other 9V battery.
So a wire came off the input jack and i think a new jack is needed too after i soldered the wire - it no work.
- Do i need to use a stereo jack? As it has more than two tabs, meaning its stereo.
- I was asked by one supplier does it have an internal switch....... i dunno.
It has 2 of the same enclosed jacks which ill get a spare when i order. See...
I'm trying to clone an EHX glove but without the option to run in at 18v (I only ever run mine at 9 and I love it). I'm working off of this schematic from :
I thought I could get away with removing this section if I only want to run at 9v:
but when I wire things up on my breadboard I get no output :/ Is my assumption about the bit I thought I could remove incorrect?
I've also tried wiring up just the first half of the circuit, so cutting off everything after the C4 loopback into the...
I have a 1980 long dash Boss OD-1 with the 4558. But I have a few issues with the pedal...I think. For one, the pedal doesn't work on a battery, yet the jack doesn't seem to be shunted. The LED never illuminates, even momentarily, yet the LED is tested and working fine. Also, the pedal just doesn't sound right to me. I've never played an OD-1 before, but it seems very dark and muddy with humbuckers. The 2nd half of the overdrive knob seems to not affect the sound at all, at least to what I'm...
I have the Visual Sound Route 66 which houses a tubescreamer-like circuit and a compressor in one pedal. I have re-capped it, replacing no-name caps with better quality ones. The tubescreamer side is fine now but there is still a low noise crackle on the compressor side. It has a built-in noise gate which I have set to on. There are reports on the web that it is noisy.
I noticed when I hold my hand on the bridge or strings on the guitar, the noise disappears. It must be grounding through...
I bought a used Way Huge Supa-Puss pedal with a broken Feedback control. It looks like a 9mm D-shaft potentiometer, but you push on the shaft to cycle through the different beat subdivisions. It is labeled 2F4. On the main PCB, it is labeled RP5.
Someone mentioned to me that it could be an encoder, but I have no idea. Does anyone know what the specific part/value is?
Hello all, I'm messing around with an Alembic filter made from another user here. Everytime I make my own charge pump, it creates a lot of noise. So I just buy a voltage converter off Amazon. The first one gave me +/- 15v which was fine but I wanted to lower the headroom. I just got another variable converter that I can bring down to +5 volts but instead of -5v it gives me -15v. It stays -15v no matter how I adjust it.
I am trying to diagnose and hopefully solve an issue with crackle on a big muff pedal I have. I am new to the world of analog electronics and have built and modded only couple of pedals.
The problem is, the pedal produces random popping and crackling along with static. This only happens when the tone knob is turned up. Level & Sustain do not affect the frequency of the crackle, only the Tone knob causes this. For what it is worth, I poured 91% isopropyl alcohol into all of the pots and...
Hi all, love the forum and I hope this is in the right part of the site.
I recently built Fuzzdog's String Stinger Drive - which I believe was traced first here. Build was smooth and all worked as expected, so I guess this is more a schematic analysis question.
It loses all sparkle at the top end, is there any way to remedy this? If I were to make a slightly educated but mostly uneducated guess I'd say that the secret lies between R14 and C5 values. Would there be a way to make it sparkle...
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