Hey guys,

I need some help with biasing the transistors in this Build the Wolfgang 61. I adjusted the drain voltage to around 4,4-4,5V expect for Q11 because I only have a range of 9-6,5V? I’ve got some sound out of it but the volume was so low I had to crank the volume of my 120w stereo combo to like 7-8 to be able to hear it very quietly when I wanted to increase like postgain r for example it started to make weird sounds and would get loud as fuck also there wasn’t any real fx applied to...

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

Good day,

I'm trying to fix my phase 95 mini. smd
the 90mode is inaudible, the 45 is working fine.
I thought the switch was the problem, but seem like the mxr switch is different from the center common switch I used.
I know is PITA to work on smd , but If someone can help which component to check or replace, i can work things out.
Sorry I dont know which schematic they used for this too

here's the board

the 45/90 switch is on the right on this pic. I just desoldered it from the pic, it's...

Here's a trace of a J. Rockett Tim Pierce signature OD that I had on hand. It's a dual pedal with a four-knob OD followed by a MOSFET power amp boost. This PCB is stenciled rev 5 and the pedal dates from 2015. This post is mostly for curiosity's sake since I couldn't find an existing trace. It's a decent but not spectacular pedal and there's nothing innovative inside.
TimPierce8.jpg
TimPierce7.jpg
Tim Pierce OD Analysis.jpg
Tim Pierce OD schematic.pdf
The most interesting thing about...

The Sonicake Volwah is an extremely affordable, real estate saver of a pedal, with volume and cry baby wah style combined into one tiny enclosure. It has two LEDs which seem to be RGB to me since they are green when Volume mode is active, and red when Wah is active.

Without questioning it's build or sound quality, my main issue with it is that the LEDs are UNDERNEATH the expression surface. This pedal really small so you can't see it entirely when it's under your foot and that's just part of...

Guys

I have an Blackstar HT Dual pedal Im trying to fix. I purchased from eBay. Shortly after I noticed a problem in the switching. Negotiated a 50% reduction on the basis I would fix. Im not a pro but have built fx and fixed amp problems before so am confident in tackling this.

Wanted some advice before I open the box though.

Symptoms are...
Unit always works in Bypass
Sometimes either green, red (or both) channels are silent.
Sometimes the volume of green or red channel will dip randomly....

Intro

Hi everyone! I had the chance to get my hands on the MXR Doubleshot for a little while, and found out there are no available schematics anywhere. It's nice to do some selfless circuit tracing once in a while, in the true spirit of FSB.
Starting from what was known already, the Doubleshot is usually described as the dual channel version of the Dime, and we'll see this is accurate. That circuit already has something interesting in its own right, but this one builds upon it with the...

INTRO
Hello everyone. The Blues Driver always pops up among the most popular overdrive pedals, no doubt because many people like how it sounds, but also because it's easy to find and relatively affordable, being from one the biggest pedal company in the world. It's not as popular in the DIY world, aside from mods, probably because it's not the smallest circuit and uses many transistors in a discrete op-amp configuration. Also since you can get it anywhere for cheap, I guess most people just...

hello guys!

i built one and sounds pretty good but there is not enough gain.... i measured the resistance across the gain pot and it shows around 45K (some parallel resistance?), after that i disconnected the gain pot entirely and measured the resistance between IC pin1 and pin2 with the same reading....what could be wrong here.....
Thanks in advance

I've played these a few times and always liked them.
The usability is insanely bad, you have to have fairy fingers with the stock knobs in order to use the second gain knob. The stompswitches are way to close together.
Anyway, I found one used and picked it up. Was surprised to find mostly through hole components, and pretty well made. Not surprised at all to find a sanded IC. :roll:
I started to trace and to be honest with y'all, I got bored. I did find a few discrepancies with the RC...

Hi guys,
I was just reading a lot of topics and I'm looking for clues to repair my EHX Memory Boy.
It was stored for some years, and now i can't get any effect out of the pedal, i already tried battery, and AC, and the behavior its the same, i can turn it on and off, i have sound, but no effect...
Delay and Depht doesn't affect the sound and blend and feedback just do some type off modulation turning the sound imperceptible.

Anyone can help me with this one?

I've been hunting down this pedal for a while after EQD featured it on their youtube channel.
This is second version, 350 made for prymaxe. There is a V1 of which only ~20 were made.

zapmachinev2.jpg

PCBtoptraces.jpg

PCBbottraces.jpg

Here is my guess for V1 based on the screenshot below from that youtube video. THIS IS AN APPROXIMATION, USE WITH CAUTION.
Specifically, I'm not sure about the emitter connection for Q2, either the 1K or 470R might be an emitter resistor....

Hi, gang! Here are some gut shots of my Memphis Tremolo modulator, and also an x-ray component side shot of the PCB showing parts & placement. I have seen gut shots of many other Memphis pedals online that use the exact same PCB! VERY clever engineering! I had originally intended to draw up a schematic also, but I'm too lazy to do that by hand anymore. Perhaps a group member might suggest an intuitive (like: drag and drop schematic symbols from a list) program for drawing schematics?

pls delete

Hey - I had some time between jobs to kill, and after building several circuits from PedalPCB I've started learning PCB design with KICAD by building open-source versions of classic effect circuits. I'm trying to get one put together a week, focusing on classic drive and fuzz circuits with only minor modifications while breadboarding (with some luck, the pace will slow down again once my day job starts up again). I thought I'd share what I've gotten up to so far in case it's interesting to...

Speaker Line Out Isolation Transformer question:

Does anybody know what Type/Spec ‘Isolation Transformer’ Suhr or Bradshaw uses for their Speaker Line Out Boxes? Correct resistances?

Want to attempt to make one.

I see these resistance specs options but don’t know what is needed:
— 600:600
— 10k:10k
— 10k:600 ?

— Xicon, Jenson, Edcor ?

Anybody have any ideas or knowledge on this?

Thanks for any help

Good afternoon,

I was modding an unrelated Bad Monkey overdrive and one of the mods adjusted the intensity of the bass knob. I reverted it because it was too much for my liking, but it worked really well into my DS-1.

My question is, are there any ways to add a pre-distortion bass boost on the pedal? Hopefully one that wouldn't require I add my own little circuit board into the pedal?

Yet another one bugg has posted on his site:

Box of Rock variant, with minor changes to cap values Q2/3 source resistors and D-G bias resistor of Q3 so would be quite possible to do a BoR/'59 Sound mode switch with a 4P3T rotary.

I like this more than i remember liking the BoR when i made one years ago, but i just don't like having a single BMP style tilt tone pot and am considering putting a Bassman tonestack on the end instead - If anyone has any advice/suggestions/experience of doing...

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...