Hello there,

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...

Hi all,

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:
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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...

Hello, my first post!

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...

Good day,

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...

pls delete

Hi,

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.

so (referring to Boss schematics):

- I...

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...

Hey guys,

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)

Build documents for the Wolfgang 61:

My status quo (also don’t hate me...

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...

Namaste

Hi all, I've bought a moen shaky (univibe) new pedal from 2012 and after a month of use the vibration (and rate control) stopped.

any idea?

the light at the 4 leds shines but don't oscilate.

kindly regards

x.

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...

Hello,
This is my first pedal project, so please forgive me if it looks like crap.

I though I'd start with something easy, the Lovepedal Champ, using this layout:
which is based on this thread:

The effect works as it should (I think), but I also get a loud hum whenever the effect is switched on. Could it be a grounding/shielding issue?
I have built an audio probe to test it, but I'm not exactly sure where to test, and what I should be looking for.

Here's a picture of what it currently...

I would appreciate any help troubleshooting this uni-vibe issue.

This is the uni-vibe with the vintage button. PCB UV-1 Main Board Rev. A July 10, 1997

Power supply is Dunlop ECB004US 18v
1 Amp.

Effects led briefly flashes as power supply is plugged in. Chorus/Vibrato led works as expected when activated but no effect because sw2 never activates.

Voltage regulator is ok. 18v in 15v out.
Effect switch has continuity when activated.
Ribbon cable from switch board to main board has...

Hi, Guys!

Some years ago my T-Rex Replica damaged due an issue with spike voltage. I tried to send my pedal to T-Rex, I didn't know what was the issue if it was Brazilian postoffice or IRS in Denmark, but the pedal returned to my home. I found a technician in my town that fixed SMD pedals, but this pedal according him it is complex, and he needs the schematic to try to fixed. I wrote to T-Rex, first its answer to change all the audio capacitors, but it quite difficult to him that wants to test...

Hi,
I received this pedal for repair. Totally not working.
Someone could help me with schematic?
Thank you!

Hi,
I Have an MXR Analog Chorus that doesn't apply the effect:

- The original/dry sound passes trought the pedal, in both footswitch positions;
- Its a second hand Pedal;
- I don't have the diagram to troubleshoot;
- I disassembled the pedal and verified that the TP2 is missing, and instead, there is one resistor, with one leg in C16 and another led direct to one of the U3 pins;

I need some help trying to troubleshooting this. Sorry some english mistakes.

Hi all,

This is my first post here so let me know whether I am posting in the wrong section, or anything!

I was wondering whether anyone had success building Tim Escobedo's Q&D VCF, or a variant of it (I understand that the topology is an active bridge-T filter, so variants might be published elsewhere).

simplevcf_252_119.gif

I put the second version on a breadboard with my guitar at the input and a digital cab simulation pedal at the output and all I am getting is a nasty metallic...

I just built up a BB-1 using the V1 layout found here:

Everything works, voltages to the chip pins are all correct, diodes are 4148's showing .63v forward voltage when tested in circuit. The only change I made to the schem was to sub a 330K for the 220K for a little more gain. While everything technically works, I'm getting what I can only describe as too much clean signal on top of the distorted signal. The clipped signal is definitely there, but it just has a bit of this clean signal type...

My trusty 80s Rocktek BBD Delay died. I have soldering skills luckily, and a little experience troubleshooting electronics, but only the easy stuff like blown caps/diodes/burns/shorts. I have a great multimeter that does everything, oscilloscope, soldering iron, and adjustable power supply that will display watts being used.

I tried multiple 9V center negative power supplies that work with others, then I tried a battery, no luck. When I plug it all up and I kick it on/off (I can't tell when it...