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 made a vero layout of an Ibanez BP10 bass compressor, based on the schematics of GGG. I checked it several times but could not find an error so far. But my build does not work. I checked the layout again and did the typical soldering troubleshooting, but no success. So I give up and will do some other build. If anybody wants to continue and do some debugging - here it is for free use.
I'm a new member and new to pedal building. Thanks for the forum!
I just completed a build based on the Small Bear Electronics Ursa Minor distortion circuit.
I completed the breadboard build and liked the sound of the two main options a) using a Darlington pair of transistors, and b) asymmetric diodes using an Si b2b with a Ge + Si. In fact, I liked it so much I decided to do a full pedal build.
Shipping costs to Australia made ordering the dedicated PCB and enclosure uneconomical,...
Just wondering if any of you have experienced this weird issue with an Ibanez Tube Screamer? here's what's happening:
* Initially the pedal seems to be working fine when it is in bypassed mode.
* When you stomp on the little foot treadle to un-bypass the pedal there is a weird swell effect where the volume starts off soft and gradually gets louder.
* When you stomp on the little foot treadle to bypass the pedal, there is the same volume swell effect.
I have a Dunlop UV-1 that's giving a really soft effect. The controls all work and you can barely hear the changes. I've replaced q16-q18 and tested caps with no success. The bulb is working, but seems to either be not getting bright enough or dark enough. I'm getting the 15V on it. What should the voltage range be on the other side?
Can anybody tell from the schematic what it should be?
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.
Hello there,
Im building a little Vox treble Booster v807 clone. Very simple, no controls.
The pedal is working fine when activated BUT the Bypass signal is non existent - no sound at all, not even when I remove battery.
I have checked the dpdt footswitch wiring and even changed the footswitch all together. When I remove the ground wire from one of the lugs of the footswitch (as per your standard pedal wiring diagrams), I get a bypass sound that is reminiscent of Tone Suck aka complete loss...
I was just going to use my Digitech QM-1552 Digital Multimeter to test the diodes in my Ibanez TS-9 Tube Screamer to see if any of them were faulty, I switched the multimeter to its Diode/Continuity test and then my multimeter let out a beep indicating continuity, I thought that maybe the probes had shorted together so I checked them, everything seemed normal, the probes weren't touching each other, so I tried removing the probes, first the black one, the continuity...
Hi, I've build several Benson Preamps, but today, while assembling a new one on a new PCB, I encountered a problem that I can't diagnose.
With gain set to 50% or more there is some sort of sizzling noise, like high-pitched gating fuzz, heavily pronounced at the end of decaying notes (see video:
I've tested the circuit with two different amps and power supplies, different cables, different guitars, I changed all JFETs two times, even build another one carefully selecting every component. It...
I recently got an old V2 EHX Small stone in that didn't work. In the end I traced the problem to a non functioning EH1048 IC in the LFO section. I replaced that IC with a socket.
- With a spare EH1048 I got from another pedal I get a fine working EHX Small Stone
- With a CA3094 I don't get any working sounds
In all the schematics and information online I can find that everybody mentions that the EH1048 is a rebranded CA3094.
Hi everybody, new to the forum here!
Sorry for my English, I’m Spanish.
I have built a Sola Sound Tone Bender Mk 1 ( I attach the layout I followed and some picks of the circuit) and I need some help with something that is going wrong:
I've been trying a lot of combinations of transistors with Ac128, russians... and I always get the same result:
When I use the pedal with my guitar volume from 0-8 it sounds good (or at least I think so...) but when guitar volume is on 10 it sounds crap,...
I added an input buffer, and I'm going to use it as the first stage in a larger circuit. I attached a partial schematic showing the Squeezer portion - guitar input is to the left (into R1), output into an output buffer (starts at C30, lower right).
Here's my problem: the coupling cap C4 at the output of the 2nd op amp is swinging about -3v on the negative lead. Positive lead is ~4.5v as expected. No...
I bought a broken RV-5 because I thought I could repair it. First thing I noticed is that somebody tried to replace the D1 with another non SMD diode, but I quickly replaced it with the original part. By then, I had noticed the IC6 S8520E33 was hot, so I did the 3v3 stabilization mods, except that I used a LD1117V33 with a TO 220 package (I checked and it seems to be the same as the other one; I couldn't find the SOT 223 package anywhere where I live). I soldered the 1117 with little wires...
I have recently found in my collection of pedals, one of them.
The problem is that when I step on the pedal to turn it on, the sound is faded. It sounds like the effect is only kicking in very little. If I keep my foot down on the pedal, the sound Is perfect. I believe something is wrong in the switching circuit. I've tried looking for a schematic but haven't had any luck. Any insight would be helpful.
I'm using a Voodoo Labs ISO 5 power supply...
The pedal works perfectly in 8 second mode. However, when I switch to 2 or 1/2, the effect doesn't work. When it kicks in, it basically doubles the signal overtop of the input, i.e. Just makes the sound a little warmer. There are no trails, echos, or repeats. The delay controls don't seem to change anything. The controls all work perfectly in 8 second mode however. I've recapped and swapped ICs. I get the voltages on the 4066 when sliding the selector switch. Interestingly, if I jump pins 3&4...
W20K is recommended for the tone pot, but I didn't have it in stock, so I made it with B25K.
I know that it is used as a replacement for the W20K in many TS pedals, and I also have a few TS pedals made with the B25K.
However, make my GT-OD with B25K, the tone was too dark when the tone pot was set to 12 o'clock.
I looked for other errors, but there were no special problems, so I purchased a W20K and replaced it.
I finally like to post a project I'm running a couple of months now.
I took a try on this one from april on...
It’s the BAJA Hiwatt DR103 amplifier pedal 9v 120318 from Bajaman.
Here’s the original documentation topic:
I got it on breadboard with some superficial modifications. Here's the actual schematic (including already some attempts of problem solving, see below).
HiWatt_Schematic_disfunctional.pdf
All in all it's working very fine, overall hiss are very low, no oscillations and...
Having a problem I cant solve and I'm not sure what the issue is. Basically I have small tube amp and i'm trying to add a buffered rangemaster circuit to it. To get 9V for the circuit, I tapped off one of the preamp tube supply nodes which sits at 130V. I put that into a voltage divider (R14 and R15) to drop it to 23V, and then put that into a LM7809 ic to provide a regulated 9V. The problem is with that last part, the LM7809.
- with the 7809 installed I get 130V in to the board but...
Got my Mosky Silver Horse yesterday. Tried using it and after a day this is what mine does.
Can’t return it coz I sourced it from AliExpress via another country. My mom in law carried it for me. I’ve raised a dispute with AE and written to Mosky as well. No luck so far. Trying some DIY repair if possible.
Any tips on how I should go about this ?
Any checks I can do to figure out what component is causing this ?
Was anybody successful building a JJ Rocket Boing clone using pedalPCB sproing PCB? I reflowed all my solders, checked for bridges, switched my IC for different kind of opamps without success.
The output gain is way below unity. When plugging a guitar, I get no signal at all (or so low that I can't amplify enough to distinguish it from the static noise).
With an audio probe, I notice that the signal out of the first opamp (pins 1-2 or IC2.1) in the schematic at is already way below unity. Would...
im having troubles to find what is going wrong with a Truetone Liquid Chorus and Echo Version 1. It was not turning on in the first place but i found a shorted cap close to the DC input, then i could turn on the pedal but it was acting like a bypass even though the leds indicate that either echo or chorus are ON. I found wrong voltages on the 2x 4558 op amp, i replaced them by 2 tl072 and recovered the right voltage on only one of them 4,5V on pin 123 and 567. The other one show...
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
Thought I'd pick up one of these to see what it's like.
I was hoping I'd be lucky and it would be a take on the Moen Shaky Jimi/Jimi Nova, which are based on the EasyVibe.
Here's links to the Moen Shaky Jimi and Moen Jimi Nova threads.
And I'd like to thank John Hollis for his lovely EasyVibe circuit. :thumbsup
What's inside then? The highlights:
1 x ST 064C
3 x TI TL062C
4 x LED/LDR pairs
It does indeed look to be generally based on the Moen/EasyVibe circuit although I haven't checked the...
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...
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