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.
Forum
Topics
Posts
Last post
Debugging 101 General rules and hints to succesfuly bring back that old pedal to life
Hi. I've got this Companion labeled Shin-ei fuzz wah, the fuzz works but the wah does not. I've noticed from pictures of other shin-ei fuzz wahs the wiring in mine looks different. The ground is wired directely to the wah pot. Also there is a red capacitor where it's supposed to be green. (not sure if it's a capacitor). Can anyone give me some advice on how to fix? Thanks
Hi all !
The pedal has no effect when engaged. It also has a big volume drop.
There was a shortcut due the bad shape of the Color switch. I cut the common leads and the ones at the down position and put together.
One of the transistors was dead, I put a bc239 (same pinout as the bc309's.)
I guess I can use ca3094's instead of eh1048 wich are completely impossible to find. Now there are five ic sockets for the op amps.
The ca3094 near the pot area measures 0.70v @ pin 6 with the...
I'm moving my post which was initially on the MXR MicroChorus dedicated thread ( here, since it seems to be the proper location for that!
So, long story short:
the MXR MicroChorus uses a SAD512 BBD chip which is hardly sourceable.
Fender3D provided on page 5 a complete rebuild schematic and a PCB in order to use a MN3007 chip instead
Since the original schematic and the updated one are quite close, I just made a small additional board
I basically use my rat between 8 and 8:30 o'clock - or right above zero on the the pot sweep. It is super hard to dial in with the stock design since every micro movement makes a huge difference. This is the only part of the pot range I use, so I'm wondering if there is any modification I can do to get more sweep in this range so that I can use this pedal more easily and so I don't have to spend a few minutes micro dialing it in if the pot moves a smidge?
Hello everybody, so, recently i built Civil War Big Muff clone with schematics from tagboardeffects. All the components that I used have the same values like the ones in the schematics. For transistors i used kt3102em and for diodes kd521a.
First build was not working from start, i was not getting any fuzz, just a slight distortion. I noticed that when i rolled off the sustain (distortion) potentiometer that I would get constant, high pitched buzz (sounding kike synth), after a minutes of...
I am trying to learn how to design PCB with KiCAD. My first attempt is a simple 3PDT breakout board for true bypass. Before I place an order, is anything willing to give my design a sanity check?
Hi,
I'm trying to make an inverting op amp buffer as I want to flip the phase and buffer the signal. I've attached a photo of my breadboard and the circuit I'm trying to follow.
When I connect it all up, the output is super low, -30dB or so from where I started, and it looks like my signal is being low passed. I've tried a few different resistor values from 1M to 10k for both resistors with more or less the same result. Also tried a TL072 op amp, also no luck.
I assume I'm missing something...
I built my 1st pedalboard using an aluminum frame and two diy modules made from cast Hammond project boxes.
Module 1 is a power module with an IEC plug + on/off switch. allows me to plug a power cable direct into the board.
Module 2 is a signal in-out patchbay which includes a mono guitar input/ pedalboard input and two outputs (mono/stereo)
Module 2 is my issue, I don't think I have it grounded correctly. The input jack is a metal switchcraft jack which provides a ground to the...
Hello everyone. I have a Dunlop UV-1 univibe. Its the version with one main PCB. Not sure what Rev it is off hand. The issues I'm having are, noise in the signal path and an unresponsive speed control. I get static of sorts when it's in bypass and active. I also plug in the UV-1FC foot controller and the it bypasses the speed knob but it is still unresponsive. I'm guessing it could be the the optocoupler before the intensity control. But I can't find any replacement for the NSL-39S52. Volume...
I built a lizard queef following This guide and need some help debugging.
I didn't have all components to hand so I used 2n3904s instead of the 2n2222s and used a 2n4401 instead of the 2n5088. I also didn't have a 1k pot so instead used a 10k at first and then just rigged up a 1k resistor and a 510R resistor to fix the balance at half.
I haven't been able to get the pedal to work. The led illuminates when the switch is pressed but there is no sound. The pedal also works in true...
I am working on my first pedal which is an Analog Sun Fuzz pedal from PCB Mania. I have made some good progress with help from this group. First I was able to fix my 3PDT connectivity and successfully got the bypass working. After checking some loose wires I got the LED working. It's kinda fun troubleshooting... but it will be even better when I can close this bad-boy up and play. ;-)
Situation: I have a full finished Analog Sun kit. It switches successfully, plays on bypass fine, but does not...
I completed my first build an Analog Sun from PCB Guitar Mania pedal. What a fun project! I'm excited to be trying out something new.
After final assembly I have some issues and was wondering if the community could help with a couple of Noob troubleshooting questions. Apologies if these have been discussed earlier, I checked out GEOFEX and was both impressed and overwhelmed with this community.
Situation:
======
I have completed the build (see attached pictures). I plugged into the DC...
These TC Electronics pedals from the 1980s are tricky to work on and I'm posting this information for the benefit of all brave souls that take on repair of these iconic FX!
The potentiometer knobs are *NOT* a push fit, so the often-seen advice for using string or ribbon to pull them off will certainly not work.
If you gently remove the blue top by lifting/prising your fingernail or similar blunt instrument, this will reveal a screw which releases the knob. Lift the knob off gently as there's...
I got a Deluxe Memory Boy that does not replay feedbacks at all. The PCB is Rev D as seen in the picture below.
I measured BBD clock signals in the breakaway board (detachable board containing trimmers and BBDs) with oscilloscope. They looked very distorted and amplitude seemed too low. Other clock's waveform seemed more like triangle than square.
Then I detached breakaway board and measured clock signals, and they looked very nice square wave. So, I think that...
I'm trying to fix my phase 95 mini. smd
the 90mode is inaudible, the 45 is working fine.
I thought the switch was the problem, but seem like the mxr switch is different from the center common switch I used.
I know is PITA to work on smd , but If someone can help which component to check or replace, i can work things out.
Sorry I dont know which schematic they used for this too
here's the board
the 45/90 switch is on the right on this pic. I just desoldered it from the pic, it's...
since we are again in lockdown and I had to occupy my time, I thought What about taking out one of my old SD1 out the drawer and mod it to get the most transparent overdrive I can get ,like my Timmy for example? I love the Timmy transparency, that pleasant grit on the highs, the crunchy round bass.
My idea was to get rid of all the component that trim the bass and cut the high, flatting the mid hump, It turned out it's not that easy as I thought.
Hi,
I built the Ross compressor clone from I'd swear I had found a youtube video explaining how to adjust the bias resistor, but I can't put my hands on it. Does anybody know how should the bias be adjusted? I think remember it involved making sure that voltage on two legs of the IC were equal, but I don't remember which ones.
Hey, thanks for looking at my post. Some help would be appreciated, if possible.
I've had this FX90 for a few years, just lying around and recently realized/discovered
that it is good for slap back, rockabilly-esque reverb or delay. Slap back... as I said.
It works great and sounds really good with rich tone and a nice slap back, like I was hoping,
but after about 10 or so minutes of use (time may be somewhat inaccurate) it begins
to lose it's effect. It still passes signal whether on or off...
I don’t really understand how to wire the two switches especially the order switch and how it needs to be wired. Would anyone be so kind and help me out with basic a schematic? The ones I found in the internet where always with three switches and today I’m just too stupid to understand anything and I want to get this build done.
(I think me going from output of the switch to the output jack is also just wrong)
Hello all, I just tried my first pedal mod so some issues were to be expected. I did the R28 Script Mod and Univibe mod using Stinkfoot's guide ( The ony thing I did differently from the stinkfoot script mod was adding an SPDT switch for the R28 mod instead of just clipping the resistor. The Vibe mod seems to work as I did the R28 first and that's when I noticed the issues. Even disconnecting the switch and putting the R28 resistor back to how it came stock didn't fix it. With the switch back...
Hi guys.
A friend of mine gave me this MXR MC-402 boost distortion pedal. When I press the BOOST switch the pedal goes death silent. Blue LED comes on but no sound. When I press it again the LED goes out and sound comes back. I checked the footswitch and it works all right. There is a transistor (Q8 on the PCB, J177 I believe) which checked continuity between drain and source when in the circuit but was OK once I took it out. Also there is this IC TLC2262 which tests suspicious while in the...
I have a rangemaster circuit on my breadboard and I am trying to get it to sound right. I tried several PNP germanium transistors which I measured for gain (selected those with 70-160) and leakage (selected those with <150ma). I am not sure I am biasing the transistor right though, so any help will be appreciated. Here is what I tried so far:
I start with a R1/R2 voltage divider where R1 is fixed at 470K and R2 is a 100K trimpot. I adjust R2 to get -1V at the base and then measure the voltages...
You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot post attachments in this forum