Hi everyone,
I tried to make a Sans amp Bass driver, with some mods.
I added a parametric eq with the shematic of a JHS Haunting mids, and i added a Max1088 to run it on 18v from a 9V power supply.

Everything is working perfectly BUT! i get a lot of distortion form the parametric EQ. (If i bypass it removing c19 and c36 and replacing it wirh a wire, the distortion goes away.)

(i have to say that a long time ago i tried to built a haunting mid and i had the same issue. I thought it was a...

A have a broken guitar pedal that doesn't work. It's not true bypass and the signal on the output is the same as the one on the input, plus the switch does nothing (and the LED stays always off). But my guess is the switching is not working because of the low voltage - the battery is ~9vDC but as soon as I connect it to the pedal it shows ~4.5vDC (half the voltage). It can be measured on the battery itself or on some of the ICs. And also the battery drains fast, say 2vDC after sitting plugged...

I got this little tank from an old blazer 158 and im trying to make a pedal with it, but Im having an issue.
I have seen people doing this setup where they just connect a reverb tank to the send/return.

Right now my signal chain for testing: Guitar>Overdrive pedal> goes to tank input, tank output> Distortion pedal> Amplifier input.
I get a sound when strumming the springs but not from the guitar unless I crank up both Overdrive and Distortion pedals wich gives me a very weak signal.

Do I need...

Hello, I tried asking about this in the thread ( Darkglass Tone Capsule in modern stomp boxes. )
But it seems to be kinda dead over there . I had some pcbs made using the schematic in the thread and built one up. It fired right up the first time and I thought Awesome, sounds great. Unfortunately after about 10 minutes it started getting distorted and loosing volume. If it sits for 20 to 30 minutes it works perfect again for about 10 mins. I tried audio probing without any success. I recently...

Hi all,

My MXR Delay System 2 stopped doing what it should do - the signal still passes, but no delay is added.
The previous owner had it services by Charlie Chander. Capacitors and memory chips were replaced, this must have been around 8 years ago.

When I switch it on, delay shows around 2800ms, or around 1400 when I remove th extra memory module. No matter how I twist the knobs, it always stays around that same range.
I tried replacing the memory modules today, but no change whatsoever....

Hello!

I am having some trouble with a fuzz pedal I built and I wanted to check if this was a common problem.

I built the Arbiter fuzz face circuit but with NPN transistors (you can switch each transistor separately between silicon BC108C and Germanium OC140s each with typically recommended hFE values with low leakage).

I adjusted the resistor values to Roger Mayer’s Hendrix mod (470 ohm —> 1k; 8.2kohm —> 18k; 1k pot —> 2k).

It sounds great with all transistor combinations - but only at...

Hi all. I'm trying my hand at a BK/Baja Tube Drive kinda thing and running into issues. I'm wondering if there's something i'm not getting. The original units ran off 120VAC, with a transformer to step down to 12VAC. 12VAC went to the tube filaments, and some rectification happened to provide +12VDC and -12VDC rails. Bajaman's unit did the same thing but ran off a 12VAC supply, thus eliminating the internal transformer. Schematic like so:

I have seen other (lesser) hacks at the circuit...

hello thank you for the addition, I have a problem with my avalon U5, there
is an R83 resistor which burned when connecting it this morning, I do not
know what the value is I can send a photo too, because I do not know not if
my request is send to the right place. thanks for your help gaetan
I am also looking for the values ​​of R84 and R67,
is the circuit available thank you

Hey all, I could use some suggestions because my dad and I are stumped on this problem. I have no real skills with this stuff, but my dad is a retired electrician and I wanted to make my Wiggler’s rate knob more useable with the simple mod mentioned in this post:

So I brought the pedal to my dad and he soldered the resistor as described and put the pedal back together. I tested it out and it was successful. The rate knob was much slower to accelerate and more useable. But as I was playing and...

I have been given a Boss NS 2 Noise Suppressor which is damaged, 4 wires are not connected to their respective tags on the jack's. Is this correct

Green from 6 on the PCB to Send jack

White from 2: to Output jack

Red and black to 9v Battery connector

Trying to repair a '78 Bi-Phase. The B side does not work. Dry signal goes through, no effect. LED on that side does not light up. Footswitch was tested and works fine. A-side works perfectly and sounds amazing. Took apart, removed the B side LED and it is dead. Removed the optical switch (which is in the same circuit) and it is dead. Measured the same voltage going to the B side as goes to the A side. So, what do I replace the opto-switch with? Don't mind making one, but cannot find a similar...

I'm repairing a Vintage Morley PWB and it has a very weird compression happening when the Boost is engaged.

I've replaced the electrolytics in the unit as they were all failing, I've tested the transistors, replaced a few way out of spec resistors (4.7M and 2.2M). Checked voltages and I have 48V to the bulb, 28 Volts on the 25 Volts rail, and 65 Volts on the 55 Volts rail. I assume the voltage raise is due to AC power being 122 volts at my place and the units were designed for 117. I have...

I have my friend's PS-1A Phase shifter here (with footswitch). The pedal does not phase at all. The trim pots were the stock ones and seemed to be intermittent/not working - pressing them (or one in particular) would cause some phase sound to occur but then die out. I replaced all 3 with new 10k trimmers (same value as stock). However replacing them didn't seem to fix the problem.

I've read other posts (either here or on some other forum) that the trimmers are highly sensitive and shouldn't...

Hey there all,

I recently picked up a FZ-1A. It didnt sound that great from the start. I replaced the 1uf caps and that made a huge improvement. Now i find it sounds like there's a cranked up compressor is in front of it. There's absolutely no attack but it sort of blooms after a second. Also there is very little volume increase when both knobs are cranked. Is this normal for this pedal?

Thanks all!

Hey all!

I know there's a million posts on Rat's but I thought I'd ask another :)

I'm looking at the below:

And from the component list there's a few changes between each variant, not just the diode clipping:

But I've seen a lot of posts saying just change the clipping diodes to toggle between variations - so wondering if the toggle of diodes is enough or should the extra components be changed too?

I'm looking at trying to build a multi-rat pcb and toggle via rotary - hence the...

Heyas!!

Sorry if this isn't the right place for this topic.
I'm a beginner but long time enthusiast of DIY electronics.
I'm building a new Big Muff and I want to be able to dial different clipping options to the unit, however I want some expert advice in order to make sure I got this right.

I'm using the amazing VeroRoute ( for designing this PCB.

2_nodes_6_way_switch_1.png

Details:
a) it's a 2P6T switch.
b) the single diode positions (D1, D2, D3, D8, D9 and D10) will be used with each...

Hi,

Please help!

I have finished up a PedalPCB circuit but have a couple of issues. I have attached an annotated schematic with voltages. Readings taken with pots 12 o'clock.

The pedal works - bass, mid, treble, presence and vol. seem ok but:
- very little distortion
- sound has a lot of treble rolled off
- LED is slightly lit in bypass mode - leakage somewhere?
- gain pot and switch does nothing
- volume pot needs to be at max for unity gain if other pots set at 12 o'clock

Probably a...

Hi there, just acquired FX20B Stereo Phaser, but it doesn't sound very stereo to me, all the swooshing only comes from the left channel, the right channel seems to be just the dry signal.
Is this normal for this pedal or is there something wrong?
Shouldn't the swooshing effect be across both channels?

I build the baja reactor when i plug the power the sounds starts fading until it has no sounds at all. Unplug and plug it in same thing happened. Thanks guys for helping...

OK so I built a tube preamp with 3 12AX7's running on 190VDC to the plate and 12V to the heaters. I use a SMPS to convert 12V to 190V and the whole thing is powered by a 12V 1A wallwart

On start up, when everything is cold, I plug the power and I hear audible clicking coming from the relay for several seconds until the tubes warm up, when the tubes are warm, nothing but standard operating noise

This is the schematic, any help would be appreciated

Hi there, my pog when I plug in my pog to power the led flickers for a few seconds. During this time if I push the bypass switch it seems to crash. If I reconnect power a few times it starts up normally. I thought it seemed like a capacitor issue but they seem ok. Does anyone have any ideas? I’ve found some similar questions on line but no one seems to resolve it. Thanks

Hello all!

Picked up an '85 ProCo rat today locally. Seller sent me a vid of the pedal working, and pics of the circuit/chip so I jumped on it for the price.

First thing I did when I got home was open in it up. The pedal had a battery in it and I noticed it felt slightly warm to the touch (oh boy). I found that someone had repaired the battery snap cable with electrical tape, cool...

I'm also seeing some very ratty (no pun intended) soldering/wiring work

Can someone tell me what's going on...

Hey there,

Long time lurker. Intermediate pedal modder.

Haven’t had a rat in awhile and picked one up for short money. Decided to do a few mods:

MOSFET hard clipping(irf520), silicone diode asymmetric soft clipping, changed the 4.7 to 1uf in the clipping frequency response, added a 1k and 10k trimmer to the 2.2 and 1uf caps, Changed filter tone cap to .0068. That’s about it. Took maybe an hour altogether.

Plugged in the correct 9v adapter to the pedal and started to get burning smell....

Hi everyone,

I have already asked the same question in the neighboring forum,
I've just finished my clyde clone with a custom pcb layout bought from a supplier in Europe with a Whipple inductor and ICAR pot. The only change i've made to the original components values is the 1k5 resistor to 1k8

i've used mostly modern components (except for the huge PIO caps i had from an unfinished project :D).

The issue i've run into is that, when the pedal is rocked to the toe position and when hitting...