I traced this one a few months ago and never got around to putting the schematic up here. The only thing that bothers me is how the 9v supply is hooked up to the cathode of the bypass LED. I still have the box but the owner is not willing to desolder the caps to find the values. Any way to measure them in circuit to get a rough idea of what the are? In my experience NP0/C0G caps are usually lighter in color....like a grey and the X7R caps are a darker brown so that's how I marked them on the...

Has anyone modded the GDI-21?
I think I'd like to add a mid control to it, True bypass, and fix the darn squealies the thing makes with EMG pickups.

I'm also considering using them as building blocks to build a 4 channel preamp.
I have a Tech 21 tri-ac that I love, and the Behringer GMX amp as a backup.
The gmx looks like two GDI-21 with a different input configuration on the jack.
The GDI just sounds like crap against the other two.

This is my first time posting here... I've been trying, for the better part of a year, to obtain this pedal. It beautifully replicates the sound of the Beatles - and much better than premium and expensive alternatives like Aclam's Dr. Robert or Jext Telez's White Pedal (no dis). Hear for yourself! Unfortunately the maker has gone completely AWOL... I was able to get a few replies from him last year but he disappeared. I think he's had enough with making pedals. His website and official social...

Does anyone know what Pro Co has done to the RAT to make it a FATRAT? I'm talking actual circuit and/or component changes not sound/features. If anyone has any gut shots or an actual verified/traced schematic that would be great. I'd like to update my comparative multi RAT schematic (below) to include this new RAT variation so I'm really curious as to what they've done.

Hi, I'm putting together a Troglodyte fuzz from the layout on dirtboxlayouts.blogspot and just wondered how critical the choice of NPNs are for Q1 and Q2. I've got a couple of low hfe (≈150) and just figured I'd throw them in there and see.

Troglodyte Fuzz.png

Hi all, this project was one that I wanted to do for a while. It's been pretty fun digging into how oil can delays work and sound. Don't Tell Ray has a front end that can get gritty and dirty, a sinusoidal LFO, modulation speeds that match the hardware, and a tone control that allows the delays to stay nice and clean or dark and mellow. I have a full rundown of how the circuit works on my page about it here: Here is the demo:

Hello, I wanted to know if it's possible to add manually tags like or to my topic title. The simple reason being is that I often post the right in my first message, but I didn't find a way to add the colorful clickable link to the title myself. BBcode doesn't show properly in the title and I even ran out of characters. Usually a moderator or the admin himself swoops in and adds it in little time, but I wanted to save them the work if I could.

I’m planning a guitar build and trying to figure out the electronics wiring. I don’t fully understand switches, whether to us a DPDT or a 3PDT on/on/on.

Here is what I’m wanting to do:

HSH pickup configuration. 3-way blade pickup selector, wired Neck, Neck/Bridge, Bridge.

Then a separate mini-toggle: up - middle pickup only (shuts neck & bridge off). Middle - uses only the 3 way blade, for just neck/bridge options. Down - middle brought in with the neck/bridge.

I have an idea how this...

Guys,

below some line6 M9 gutshots. I need to opened it to replace a bad LCD and took some pictures.
The M9 schematic is attached as well.
Maybe it help somebody.

Cheers,

Vanderson

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I was wondering is it possible to run 2 different power supplies within the one effect pedal. With one supply being
+15V -15V from a 9VDC source through a charge pump. With the second power requirement for a second part of the circuit isolated from first part also powered from same 9VDC source, only this section powered as +9v and 0V GND with bias for op amps.??? If this is possible, I were hoping some kind people here could please advise me on how to achieve as much, even a pictorial basic...

There are several schematics that come up when you go looking for Yamaha NE-1 , and they have different ways of showing the dual pots orientation & it's a bit confusing for anyone new to these things. I wrote to Silentfly the first time I looked at this project years ago and his is a mistake in the schematic , and I think the wiring in the drawing of the pots in the Paul-in-the-lab schematic is at odds with the Freestompboxes one and possibly wrong. I know it's a simple thing to just try wiring...

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...

Hey all,
first of all I may be posting in the wrong section, so mods, feel free to move the thread wherever it should be.

So I've read here and there about DemonFX and how they might be copying the cosmetics of famous pedals but not necessarily their schematics. That seems a bit silly and I don't see what they would gain from only doing half of the job.
Also I have read on Reddit someone said that Josh @JHS had (reportedly) had a look at the AT-DS and said it was not the same as their AT+ and...

Hello

This is a nice and rare rack mount tube preamp from the early 90's from Jackson. I have traced the power supply and created a schematic. Its just a simple linear supply.
I was thinking about reverse engineering the whole thing. Leave a comment if you want me to trace the entire thing. If I get enough interest Ill do it.

I posted a YouTube video about it on my channel:

JacksonJX3_PowerSupply.jpg

Peace out.
Pete

Anybody ever mod an Arion Stereo Flanger? I could use any help I can get as all I can do is switch out parts, no real technical knowledge at this point. But I do like to take the stuff apart and put it back together, especially when it sounds so much better after changing a couple of parts. Anyway if anybody can give me some info thanks very much.

Hello everybody.

Please excuse my english. It is not my motherlanguage. :-)

I already build a few pedals from pcbguitarmania and other sites. The only time i had to adjust something was when i build a phaser. In that case it was done by ear.

I`m not sure what to do with the three trimpots on the calvin vai.
How should that sound? Are there some voltages i should measure somewhere? Nothing about the pots in the building docs for that pedal.

Would someone be so kind and can advise on this?...

Rocktek Super Delay ADR-01

Gut shots of Rocktek's Super Delay.
All the parts are identified but I have no time to draw the schematics at the moment.

Some traces are burned (due to inadequate power supply I guess). Someone fixed that with some jumpers (two orange wires). You may also notice that the black wire for the battery snap is on the hole marked with (+) on the PCB, and the red is on (-). But that's OK, the wires are reversed at the battery snap too, so everything is wired properly....

Greetings all. I hv a FX90 Delay that is misbehaving. I only get dry signal. LED switching off and on.
I hv a scope, sig generator and audio trace at my disposal. I'm trying to understand how the pedal switches off and on. From the 4007ic it goes to a diode then to the mosfet which actualy switches the pedal off and on. I can hear a signal from the 4007 into the diode but nothing out. I replaced the diode but still nothing. I should hear my generated tone on front and back of diode right?