Looking at your schematic, when the mosfet is off it will clip any signal that is larger than 1.4 volts peak to peak. This may or not be an issue depending on the pedal, however the mosfet is always in the circuit even in bypass, so the pedal could potentially clip the guitar signal when bypassed. I...

Won't the intrinsic diode in the mosfet potentially clip the unbypassed signal?

Andrew.

It looks more like a RAT than anything else

buffer (necessary for jfet bypass) -> gain -> hard clipping / high end roll off -> make up gain -> tone / volume


Andrew.

With the 10k resistor and a 5n6 in the op amp feedback loop makes a low pass filter, high frequency cut off is set to 1/( 2*pi* 10x10^3* 5.6x10^-9) = 2.8 kHz

Changing the cap to 1nF moves the cut off frequency to 15.9kHz, so it is now a full range booster

Andrew.

I would put the the uC on a breadboard and hook up LEDs / resistors to the output pins. Then you can easily see what's going on

I would also manually connect the relay to +5v and ground and listen for a click as it changes state. Then swap leads and listen for it to go to the other state.

Andrew

Check out www.aresaudio.com

For what exactly?

Andrew.

That's similar to what we have started doing. I have used the attiny13a - it can even be programmed with the arduino IDE. It's only about a dozen lines of code so the inefficiency of using the arduino platform doesn't really matter.

Andrew.

The electrosmash site has a good discussion of the Rat

http://www.electrosmash.com/proco-rat-a ... rtion.html

Geofex has a good tube screamer discussion (and electrosmash as well)

Andrew

My quick analysis would be to calculate the crossover frequency (2 *pi * R * C ) At frequencies far below the crossover frequency consider the cap to be a open circuit and calculate the gain. At frequencies far above the crossover frequency consider the cap to be a short circuit and calculate the ga...

Can you accurately measure transistor specs in circuit? I would think you would need to remove them from the circuit to get accurate measurements.

Andrew.

The standalone app is icircuit.

http://icircuitapp.com

Andrew.

Falstad?

http://www.falstad.com/circuit/

Andrew

Is that mictester's relay switching scheme in the lower left corner?

I see a spst, relay, 2 transistors, a small ignal diode, an electro cap and a couple of resistors.

Ie https://www.freestompboxes.org/viewtopic ... 13&t=13295


Andrew.

Check out the cool method of connecting the pcb and the enclosure (bottom right of pcb photo)

Andrew

If it has too much bass I would first check that R4 (47 ohm) and C5 (2.2uF) are the correct values and soldered properly ( I am referencing the numbering on the electrosmash website linked below)

http://www.electrosmash.com/proco-rat

Andrew

Great second post.

Thanks for contributing.

Andrew.

I'm a BF nut myself, and I'm mystified that people would want to hack them up In 1993 when that was first published, Bassman heads were not considered vintage. They were not very expensive and people modded them without a second thought. I think most people these days would see the value in keeping...

I don't think so - I found a data sheet for this relay



You want an EA2-5SNU relay (single coil latching)

This is a EA2-5NU (Non-latch type)

Andrew.

It looks like a standard normally open tactile switch used in many pedals. I think smallbear has a replacement. I would just go ahead and replace it it is the most likely cause of the problem.

Andrew.

.

Tayda is currently out of stock of J201s and 2N5457.

I am curious if they ever get more - I don't think the through hole versions of those are made any more.

Andrew.