Hi guys,

Someone just gave me an RE-20 echo pedal to fix. Power LED comes on but the pedal is dead. Switching LEDs don't operate either. There's nothing obvious inside that looks to be a problem - no burning anywhere, no fluid residue. I going to check the crystal right now but I don't have any info at all on this pedal.

Does anyone have a schematic for this unit? I can't find one anywhere!

I wanted to leverage the expertise in this forum over a question about how to troubleshoot audio bleed noise. I have pedal that this is occurring and I've tried to troubleshoot it to no avail. But foremost, I'm actually quite interested in the root cause of this phenomenon.

The pedal where I have been observing this is a vintage EHX deluxe big muff EH3054C, the series/parallel version.
The scenario is the pedal has two outputs:
1) compressor out (which is always on)
2) Fuzz and compressor...

Hello,

I've just finished my build of the Black Arts Revelation Super Bass Debugging clone based on this layout :

And 2 strange things occur :

1) Potentiometer seems to have effect only on the last quarter.

I've checked values and i have the same as the layout indicate (100k A x2, 500k A)

2) when i turn the effect on, the “gain” is not immediately as the good value, i can here like a “swelling gain”.

After ~1sec it’s ok.

Just for information I have not found an y 6k resistor so I...

Hello everyone!

I found some NOS transistors in my parts box and realized that these were used in the input buffer of the ubiquitous Boss NS-2 noise gate. So I decided to cut and paste that part of the schematic to build a couple buffer-in-a-box pedals. But when testing them I realized that the signal seems weaker when the buffer is on compared to bypass mode. I confirmed my suspicions plugging into my soundcard and seeing about 5-10dB difference on average between active and bypass.

So I...

I have a Boss OD-1B on the bench. Passes signal in bypass but nothing when circuit is activated. I've traced sound up to pin 5 on the RC3403adb chip but I have no sound on pin 7. Is it safe to assume the chip is bad?

Hi all,

Could you help me out with my T-Rex squeezer? I got it as a defective extra to another purchase, so no idea about its history (wear on the screws indicate that it has been opened before!).
It has very low output. Only when cranking both gain and level to max do I get something close to the input signal level through. I think I checked some simple items (see below), but my electrical background is by no means sufficient to understand or follow the schematic... hopefully someone here...

Hello, this is my first post here.

I cannot figure out which way to orientate the two cermet trimpots on the Tayda Tone Bender PCB.
Looked online and couldn't find a solid answer.
On the PCB, there are two holes with circles and one with a square shaped hole.
Does leg no. 1 of the cermet trimpot (one with dot marked) feed into the square shaped hole?
Pedal has been wired up for PNP. content_dhb15_caps_pnp.png content_dhb15_pcb1.png IMG_5343.JPG IMG_5343.JPG

Please help me, thank you!...

Hi folks, I've got one of the above units (the 3 switch version) in for a repair. It works for all of 10 minutes then cuts out/goes glitchy and really fuzzy (way more than it should, sounds like the speaker has gone).

I've been in touch with Tech 21 and had a lengthy hack and forth but I'm not getting much luck. I've found a schematic on this site so that's a start but the jacks need de-soldered to get the board out to inspect it. Do any of you have any ideas on what I should check when I do...

So I've had this old green sticker BF-2 that never worked. I was from a guy who passed, wife sold his pedals and I bought it. It was cheap and felt bad about complaining so I kept it for about a decade at this point.

The issue is: the pedal definitely suffered some water damage. You can see the rust in the board and inside the pedal. It was probably partially submerged for a while.

The pedal turns on and sound passes through, but there is no effect to be heard. You can maybe hear a...

Hola,

Just got an older block MXR Phase 100. Love it, but I feel there's a little bit of volume loss when engaged. I did TB it so that may be culprit...

Is there a resistor I can swap out that would provide a little more output level?

OK so I am asking for a bit of a sanity check

I built a high voltage tube preamp to use primarily for distortion, thing is I planned on using a high voltage mosfet output buffer like in most amplifiers but that didnt really work so I jury rigged 12 volt Jfet output buffer which is not something I've seen in FX loops

Could it be that a 12V Jfet output does not have sufficient headroom for the amount of output a typical high gain preamp has?

Hello I have a very noisy Deluxe Electric Mistress V1
This circuit :
I've modded it to this circuit (Deluxe V2) :
I thought it would help but it didn't.

I did a recap, a good calibration.
I've read a lot of things in this forum and I tried a lot of things. But there is still a lot of noise at the output. I even had a spare SAD1024 hanging around, I've swapped it and it didn't change a thing. I've also replaced the balance 1K trimmer.

Thank you for reading and for helping if you have any...

Hello. I built a 00funk and it sounds really good. However, I noticed a 'pop' when switching it on (bypass with a 3PDT). I measured 0.3Vdc in the output when active what seems really high to me to be capacitor leakage... but, could it be possible the it is caused by capacitors? I used electrolitic for the last 4u7.
Could it be solved by adding a pull-down resistor?
Thanks in advance

Hi, my big box EHX frequency analyzer EH 5000 box / EC 9000 pcb suddenly quit working, I only get the pure tone generator sound on output, Blend ctrl. and tone switch do not work anymore. Switching tone switch ON cuts down output signal completely. The pedal is modded to FX On Status LED and EXP pedal Output, using the Direct Out with a stereo jack, wired parallel to the Shift ctrl. It used to work fine during a long time after the mods. So I need some help to fix that great pedal.
Thanks for...

I've built a tube driver in the BK Butler / Baja / Madbean Archibald vein and just noticed something that i've not come across before. I'm getting hum (120Hz) when using linear power supplies such as a Boss PSA-120T, but i'm not getting any hum when using a switch-mode power supply such as the Boss PSA-120S. I've tried it with a variety of power supplies and all of the linear ones hum, and all of the switch-mode ones are fine. Anyone know what's up with this?

My schematic is below. The...

Hey, I hope this is the right section for this.

I recently got an Arion SFL-1, made in Sri-Lanka, and while I do very much enjoy the sounds from it, it unfortunately is very noisy. Any gain put before it and especially after it becomes unbelievably hissy. Even on it's own, I have to be careful when putting it through any gainy amp. Plus, when it is bypass, what sounds like clock noise bleeds through the signal and is very audible through distortion pedals.

I was wondering if anyone knows of...

Hey all-
I'm missing a 0.1uf tantalum cap for a phaser build.
The capacitor is Bias voltage filter capacitor.
The project is this:

I've never heard of a 0.1uf polarized cap, so I must've overlooked it thinking it wasn't polarized.

Is there any chance that the polarity isn't a must and I could just replace it with a 0.1uf MLCC?

If polarization is a must---I have a bunch of 1uF electro caps. any chance I could wire 10 of those in series to replace this part? Also how much of a difference is...

I need help! The black battery wire on my Maestro Fuzz-Tone FZ-1B is disconnected and I have no idea where it goes.
I can't find the information online but hope there might be someone on this site who can help me.
Here are a couple of pictures. You can see where the red wire is connected in the second picture but I have no idea where the black wire was connected.
I know very little about this stuff but if someone has an idea where the black wire should go, I think I should be able to do the...

I everybody, I'm new here, I've bought an old Phaser made by Pear in the '80s, sold as not working , I have changed all the opas,chacked all the voltage, and also the MC14069, the LFO section seems work well but with the pedal engaged I can only heard the clean sound without the effected sound of the pedal.
I also removed the buffer with a 3dpdt for true bypass, so the MC14007 and all the other components from the buffer section are missing.
I took from 8 the out for true bypass.
Down here the...

I found an old MXR Micro Flanger that wasn’t functioning for cheap. Replaced the 4069 and it’s passing clean and affected signal now. My issue is the regen knob seems to do nothing but make a bunch of hiss when it’s turned up all the way. Inversely, it doesn’t seem to do make the flange anymore subtle when turned all the way down. My instinct is that the tl062 is bad and always letting the full regen signal through no matter the pot setting. The pot must be good if there is hiss when it’s...

I have an RP360 xp. I had to store my gear for a few months. Upon setting up my rig again I discovered that all the presets and custom settings are gone. It will power up. Will this pedal reload all the presets on its own if allowed access to the internet or is it more involved than that? Also, is there a memory battery in this unit that may have drained? Thank you.

Hello!
Can anyone help with repair TC electronic NDR - 1. The fault is in the power circuit of the pedal, there is no voltage -12 for power operational amplifiers. Does anyone have a schematic diagram or has anyone experienced something similar? This voltage is generated using the IC CS51411.

Hi there!

I'm troubleshooting a friend's 3 knob tube driver pedal, which isn't outputting any signal when the overdrive switch is engaged.

Does anyone have a schematic for this version of the pedal?

In tracing the circuit, and using other versions of this pedal's schematics the best I can, the signal is making it through both op amp stages and both tube gain stages ok.

There is a resistor/cap network between the final tube output and the final output, where the signal is getting lost....