I kinda wish I'd tried something easier for my first trace. Does anything look very wrong here?

This looks like a TS (with some mods) with a switch that adds in extra gain on the op amp plus a JFET boost on the back. There's also a separate JFET boost stage on an external footswitch - I've added that as a separate trace below, but it's a duplicate of the output boost on the main pedal. I believe it's also the same circuit in the Flame Boost by Cornerstone.

Recently got a commission to convert this EQ to 1/4 jacks, new power supply caps and NE5532 upgrade to make it less noisy. I took a bunch of photos to post here for tracing if someone wants to have a go. I have one of these of my own too if I need to check any part values. MXR 10 Band EQ 01 .jpg MXR 10 Band EQ 02.jpg MXR 10 Band EQ 03.jpg MXR 10 Band EQ 04.jpg MXR 10 Band EQ 05.jpg MXR 10 Band EQ 06.jpg MXR 10 Band EQ 07.jpg MXR 10 Band EQ 08.jpg MXR 10 Band EQ 09.jpg MXR 10 Band EQ 10.jpg MXR...

Hi All!

I bought a Mosky XP Booster pedal (one-knob clean boost) with the idea of hacking into the pot. and wiring a jack in it that I could plug an expression pedal into so I could run it as a volume-pedal / booster with a remote expression pedal.

I do like a linear expression pedal for my purposes more than an audio taper.

Does anyone know what value expression-pedal would be optimal, or even better how I could add an expression pedal that would make the range go 0-to-75%?

Thanks!!!

:)...

Howdy

I would need help to understand if this pedal that was sold to me, has or not a problem
Basically if I connect in a series guitar amp effect, the mono output has a fairly low volume.
If I plug in the output next to stereo, the volume is ok.
There is a pronounced decrease in volume both in bypass and with the pedal on, the trimmer gain compensates for this drop.
But, as mentioned, the volume on the stereo input is ok.

In case I connect the pedal in loop instead everything seems ok.
The...

Hi there,

Working on an Ibanez AD-80 (narrow box) currently. I’m in the process of replacing a broken diode and just want to make sure this the right part on the schem? Going to replace with a 1N4004.

ibanez1.jpeg
ibanez2.jpeg

Link to schematic:

The pedal powered on (led), but passed no signal. There was one cap that had broke lose from the board and this diode. I re-soldered the cap, and will replace the diode. hopefully this brings it back to life!

Radiopratica 1970_08 Bizar Sounds.pdf

Radiopratica 1970_08 Bizar Sounds 01.jpg Radiopratica 1970_08 Bizar Sounds 02.jpg

I traced my Exar OD-02 OverDrive from series 2. Initially, I hoped that it will have the same circuit as OD-1, because most of the Exar series 1 and 2 pedals share the same PCBs, but it wasn't the case.

PXL_20221107_084857113.jpg

PCB is single-sided and was easy to see all the tracks on a light. My unit seems to be produced in 1996 or later according to the date code on the gain potentiometer.

PXL_20221107_084950567.jpg

It appeared that it is definitely not a TS variation, but a...

Hallo everyone,
Here Gebrey
Im an expert of diy and electronic diy and Ive succesfully made more than 30 effects and some amps.

Whats going on with SHO??
Maybe my chinese supplier gave me fake BS170? Maybe almost all SHO schemes are wrong?

The problem is... volume. It seems that voltage supplied is too less even at 15V.
I barely hear something ONLY if I push 2 Tubescreamer is series into SHO (forced FET by large input voltage signal)

Ive made 5 times this circuit and every time this...

Guitar Tripler Electronics Illustrated 09 1969.jpg
Guitar Tripler Electronics Illustrated 09 1969 b.jpg
Guitar Tripler Electronics Illustrated 09 1969 c.jpg

I'm working on a Danelectro 3699 (Foxxtone) (layout: and am testing by running the wiring through a breadboard to pots (which I've mounted directly into the breadboard) which is my usual testing process before boxing. I don't currently have a SPDT switch for the tone so I've jumpered it through the breadboard and same with the octave switch - I haven't wired a DPDT or 3DPT yet. This layout calls for three 50kB pots but I'm currently testing with what I have on hand until I order (50kB, 250kA...

Hi,
I bought a PCB for an overdrive. When I have the PCB fully loaded I want to be able to swamp out different transistors to see which ones measure and sound best. The transistors will be in TO-92 format. Does anyone make a solderless socket I can initially attach to the PCB to use to swap transistors? Then I'd remove the socket and solder the best ones in.
Thanks
Lee G.

Built out a janglebox using the lm13700 layout and not getting expected behavior.

Getting a mis-biased type sound, with sound only kicking in with louder notes and decay sputtering out then abrupt silence.

Video here:

Pictures of top and bottom of board:

Pins 3 and 4 are giving me an expected voltage reading of about 2.92v with a .02v max differential between them. Pin 1 is 1.31v with attack at max and 1.20v at min.

Issue seems to stem from pin 5. Getting a voltage reading of...

Hi all !
The pedal has no effect when engaged. It also has a big volume drop.
There was a shortcut due the bad shape of the Color switch. I cut the common leads and the ones at the down position and put together.

One of the transistors was dead, I put a bc239 (same pinout as the bc309's.)

I guess I can use ca3094's instead of eh1048 wich are completely impossible to find. Now there are five ic sockets for the op amps.

The ca3094 near the pot area measures 0.70v @ pin 6 with the...

PDF: 1979-4 Guitar Expander - Electronics Today International.pdf

1979-4 Guitar Expander - Electronics Today International 1.jpg 1979-4 Guitar Expander - Electronics Today International 2.jpg 1979-4 Guitar Expander - Electronics Today International 3.jpg 1979-4 Guitar Expander - Electronics Today International 4.jpg

Hello people.

I am trying to fix a Fender practice am with a loud hum noise.
the amp works but it has a hum noise (50hz) loud even when the guitar is unplugged.

- Volume, Contour, Reverb doesn't affect the noise.

I had attached the schematic for the amp Fender R.A.D. that is the same without the reverb circuit.

I tried to connect the preamp output to another amp and the noise still there. My first thought the issue is in the power supply I changed all the electrolytic capacitors in the...