Got this in for repair. Main complaint: The Howling Adjust control doesn't do anything, whether with the fuzz, the wah or both engaged.

Very cool pedal - nice smooth wah, and a really nice octave-fuzz. The tone control blends in the octave very nicely. Even better, the fuzz and wah work really well together. But turning the Howling Adjust control has no effect.

I have uploaded the schematic (it is inside the bottom plate). Clearly a shortened Super-Fuzz like effect. The Howling control is the...

Factory Schematic:
Guyatone - PS-004 Flanger- factory schematic (1981).png

Enclosure Front:
Guyatone - PS-004 Flanger- enclosure front.jpg

PCB Top:
Guyatone - PS-004 Flanger - pcb top.jpg

PCB Bottom:
Guyatone - PS-004 Flanger - pcb bottom.jpg

Hoping for some help with a Tayda printing file. I have a project that needs an Adobe Illustrator file formatted for Tayda UV printing and I have zero experience or access to Adobe. Is anyone willing to convert a regular PDF to the correct specs as a gig job? Happy to pay for your time as I need this doing urgently. Thanks!

Hello,
I don't have as much free time as some years ago so I'm selling my Transistor stock of 609 transistors in total.

I'm asking 75€ for all of them

Here is the list of what’s included:

SNALL SIGNAL TRANSISTORS

PART QT OBS
2N403 1
2N2222 2 the most commercially successful discrete transistor ever developed
2N3702 1 general audio
2N3904 9 Common, general purpose, VERY POPULAR
2N5087 5 Common, general purpose (BC560)
2N5172 5 Sam Ash Fuzz-Stainer, used in some WAH WAH pedals
2SA673 3...

I put together enough info to trace this one.

As it turns out it's a simplified Boss CE-3 Chorus.

The Coron is hard-wired to Boss Mode I *BUT* the normal output on Coron is like Output B on the on the Boss CE-3 ie. the Delay signal is inverted.

The stereo output on the Coron is nothing like the Boss unit, it just inverts the main output.

The Coron unit adds a Tone control. The way it works is it increases or decreases the pre-emphasis that is already present on most BBD based effects.

You...

Trying to repair this old baby.

Power supply is good
Opamps fine.
No oscillations from the 4047, so I replaced it and have a strong oscillator signal at pin 13, but none at pins 10 and 11 which drive the SAD1024 chips.

I pulled all three of the delay chips, but still nothing from 10 and 11, there should be a clock there, right?

Another effort after scrounging for some some pics.

It's pretty much a Boss BF-2 copy. A small number of changes here and there.

The caps need to be verified. The resistors around the second BBD output filter need checking as one resistor is different to the BF-2.

A lot of caps are unknown but you can see they even copied the 220k+220pF RC network so it's going to have a lot of similarities.

See notes on schematic for more details.

Schematic:
KMD KP-400 Flanger V10.png

Enclosure Front:...

Hi everyone!
I designed this fuzz circuit in this picture. I'm planning to build it, but first, do you have any suggestions about it? Do you notice any flaws? The npn transistors are 2n3904,the pnp is 2n3906 and the mosfet is a bs170. Any advice is much appreciated! Thanx in advance.

Here's the Pigtronix Philosopher's Tone Micro:

pigtronix-philosophers-tone-micro-trace-schematic.png

This is the newest version, which adds a charge pump for 18V operation and drops the Grit distortion section, essentially the same as turning the control all the way down on the original.

There are some very minor component changes from the original Philosopher:
Tone cap from 6n8 to 1n5 - pushes the frequency from 2k up to around 8k
Sustain pot increased from 25kB to 100kB - this was...

Along with the Alpha Omicron trace , here's the schematic of the Alpha Omega:

darkglass_alpha_omega_trace_schematic.png

Full tracing journal:

PCB available here:

Here's the Darkglass Alpha Omicron:

darkglass_alpha_omicron_trace_schematic.png

There was an earlier schematic traced from the Demonfx ripoff , but since it's technically a different pedal and the name is spelled wrong in the thread title, I figured it would be better to start a new thread. My trace has some slight differences in component values - which could represent either measurement errors from the Demonfx trace, or errors from Demonfx when they traced the Darkglass. But overall the...

This appears to be a factory schematic.

The PCB number is the same as the KP200 Overdrive PCB!

Schematic:
KMD KP-500 Analog Delay - Factory Schematic (copy).png

Enclosure Front:
enclosure front - KMD KP500 Analog Delay.webp

PCB Top:
pcb top - KMD KP500 Analog Delay.jpg

Years ago (10 or more), there was a mod floating around for reducing noise in the Boss VB-2 / BYOC Vibrato circuit. I'm 99% positive on part of the mod involved change the value of one of the ceramic disc pf caps. I remember booking a page on the internet that detailed the mod, but I've apparently lost it and I've spent the last hour Google'ing with no luck.

Does this mod ring a bell with anyone?

It's very common to mod these instruments. My friend got the bug to do it immediately after buying a Squire Bass VI.

We looked up the what the bass VI community had come up with wiring wise and didn't really like any of it. They usually try to give you every option possible with a dizzy amount of switch changes to get from one combination to the other (Thinking of this one in particular: )

My friend was clear in what they wanted: as many series options as possible in addition to all the stock...

The Magpie Octal 21 is a clone of the Combs JJ-150. The circuit is an attempt to to emulate a Gibson EH-150 amp with octal tubes. It goes from Charlie Christian to Junior Barnard.

EH-150_board.png

EH-150_schematic.png

Hi, yesterday I've found the R.G. Keen layout, and I gave it a shot. Basically it works: rate and speed knob does works, switch does work, ldr/led does work, I got output signal with vibrato but, the output is completely distorted (like a fuzz, but in a bad unusable way).
I tried a lot of IC (all get from Mouser) but nothing has changed.

I took readings of the ICs and they are numbered from left to right if you have the layout (I think I can't post it here) on hand.
Where there are 2 values...

I also think that a defective/failed output cap can be the culprit, so the first thing i would do would be to substitute that 1uF electro (C20 on the PCB, if i'm not wrong).

Hello. I wanted to create a preamp on field-effect transistors so that I could connect various overdrives and fuzzes to it.
It turned out something like this:

To get 30V I used a module on XL6009. For now, this is an intermediate version, because I plan to try it with a bass guitar and, perhaps, some other moments.

Hi,

I have got a 720 EHX Looper, which makes a whining square wave tone above 10khz when used in half speed playback mode.

Any Idea what it might be? Or how to troubleshoot it.

This is the most recent refinement of a generic boost/buffer circuit I've been using for a while. It's a soft clipping boost with a subtle crunch, like a perfectly toasted bagel. Bypass scheme inspired by Valve Wizard , diodes-to-ground soft clipping inspired by Thunderbird (and discussed in this thread ).

I used a 10k linear pot but a different taper (log or audio I suppose) would let you omit R6.
My schematic says opamp_quad but feel free to ignore that and use a TL071 or similar.
D5/D6...

Hey everyone,

I wasn't sure if I should have posted in the old Hudson sidecar thread .

In 2024 Hudson Electronics introduced the Motorcycle as a limited edition:
The Motorcycle is a modified version of our Sidecar overdrive pedal – our take on the soft clipping overdrive circuit with the added versatility of a powerful two band EQ which draws inspiration from a vintage recording console.

I have built many pedals, but I have never drawn a schematic before. I did my best to identify all the...

Does anyone know where to get a replacement DC jack for this pedal? It is not the typical DC jack, there is an additional switching element - it has 5 pins on it. The only source I found so far is

and that's a little expensive for a dc jack and not too available.

Any info appreciated

Thanks

I've been working on a WH-1 recently that didn't function yet seemed to have proper clocks and voltages. I don't have a schematic so I was doing what I could. I had another WH1 come in with separate issues, but the effect functioned after fixing. I took the opportunity to swap some ROMs to see if I could find the issue (I already previously swapped the big IC don't remember the label with no change). Swapping U22 brought the LED back, but no effect, then it seemed to freeze up. Also swapping...

Hi friends,
Does anyone have Electric mistress (David gilmour version) vero board layout?

I dont want any pcb or schematic because its so hard to build for me

I got this pedal in as it was making a lot of noise. The noise was as loud as the effect and made the pedal useless. I traced the noise to a single 470p cap.

I also traced the pedal:
BBE - Mind Bender.JPG

For pics and more info visit my blog; see the link in my sig