Proco RAT Project

[oscelf2]

Hi,
An ongoing project of mine for the lest few Saturday evenings have been to mod my RAT.
It been an excellent pedal to test and learn on as their are so many well documented mods, and quite a bit of space in the pedal.

Thought that I post the progress so far and my some of my future plans.
I have tried to keep it pedalboard friendly by not adding knobs and switches to the sides; this has required some shaving of the pcb, which has a lot of empty sections. To fit all the switches so tight I milled out a long opening so they can slide to the perfect position (covered by a plastic strip from the outside).

The mods are:
Bass Boost, inspired by:
https://marcuseffects.wordpress.com/2016/06/20/proco-rat-bass-mod/

4 different clipping options (+ no diod clipping) 2xRed led, 2x Ge 1N34A, 2x Si 1N4148 and GE 1N34A+Red led

Volt starve, Im a big fan of lowering voltage, especially on Fuzzes. The rat however seem to handle lower voltages really well and the difference in tone is less obvious.

Also have installed the LM308 oamp

Im starting to run out of space in the pedal, but I want to try to fit a Ruetz style mod. Not sure exactly how Im going to approach it. Maybe by having an internal pot to change the resistance, and an external on-on switch (between dist. and filter control) to change between stock and the pot. I always like to have the option to go stock config at any time, which is the approach I had with the other mods.   

Another really cool mod is the clean blend that Kinnatone installs in their rats. But that seems way more difficult.

I really want to hear if anyone have any ideas or tips!

[GGBB]

I think the BB mod is awesome!    My RAT is on double bass boost all the time.

See if you can hook up the Ruetz mod temporarily to try it before you decide to fit it into the closure. You might not like it.

The Ruetz v2/pot mod is just a 500-1000 ohm pot instead of the 47 ohm resistor. You don't really want to go lower than 47 ohms, so it's smarter to add the pot in series with the resistor instead of replacing the resistor. Then you just need a simple SPST switch to jumper the internal trimpot to turn it off.

[GGBB]

Also - my favourite clipping is with MOSFETs:

[oscelf2]

Totally agree, the BB was installed yesterday I so far I see no reason to turn it off 

That's a great idea! then the 47ohm becomes the baseline and the trimpot adds on top of that
What's your experience with going lower than 47?

I did not have Mosfet in mind when choosing the diods  . I could probably live without the asymmetrical clipping, so maybe that could switch that to mosfet. How does it compare to stock?

[GGBB]

Totally agree, the BB was installed yesterday I so far I see no reason to turn it off 

That's a great idea! then the 47ohm becomes the baseline and the trimpot adds on top of that
What's your experience with going lower than 47?

I did not have Mosfet in mind when choosing the diods  . I could probably live without the asymmetrical clipping, so maybe that could switch that to mosfet. How does it compare to stock?

I haven't tried lower than 47 but I expect it would just make the RAT excessively bright - the opposite of what Ruetz does - remember the original Ruetz mod was to remove the 47 altogether which is effectively making it infinite resistance.

The MOSFET clipping in the pic is higher threshold than LEDs - so you have to turn up the distortion pot to make up for that which makes the sound fuller overall. The sound of the clipping itself is similar to LEDs IMO.

[oscelf2]

that makes so much sense 
Gonna try it without drilling any holes this weekend, se how it sounds. If I like it I'll mount it; got some ideas where I might mount the pot so that its accessible externally as well (if I feel its necessary). Thanks for the ideas!

[oscelf2]

The project continues
"Ruetz" mod added. 1k pot in series with the 4u7 resistor and a switch that bypasses the pot and turn the pedal back to stock.

After a bit of moving switches/pots around I managed to fit another three-way switch that I'm planning to use for additional clipping options. Just got hold of some Mosfets (irf540, bs170), NOS germanium diodes (OA47) and 1N4148. Gonna take some time and figure out how to best do this

Really enjoy working on this little project