Rat board suggestions please

[Guybrush]

Hi gang,

I'm looking to make a multi pedal and want to include a Rat circuit but space is tight. Could anyone be kind enough to point me in the direction of a Rat board that is:
1- As small as possible (probably designed to fit into a 1590a enclosure)
2 - Includes a clipping option switch

Thanks as always!

P.S. I unfortunately can't use Brian's Runt board as I live in the UK and he's currently not shipping here due to Brexit issues. Thanks Boris!

[gordo]

Fuzz Dog's FuzzPup Rodent might work. DIYGP'sTasmanian Devil from Australia.

[Guybrush]

Will have a look. Cheers!

[matmosphere]

If you don't need the forth knob use a Madbean Runt. Wiring up the switching would be pretty straightforward. How many clipping options do you need. With two you can just solder the diodes straight to a dpdt on-on and if you wanted two with a third option of no diodes for clipping then use a on-off-on switch. Anymore and you could just make a daughter board.

[Guybrush]

Unfortunately Brian isn't currently posting to the UK where I'm based but I think a clipping options daughter board would work on the Fuzzdog PCB.

Absolutely no idea how to make one though, I'll do some searching online and see what I can find.

Thanks for the suggestion!

[benny_profane]

Unfortunately Brian isn't currently posting to the UK where I'm based but I think a clipping options daughter board would work on the Fuzzdog PCB.

Absolutely no idea how to make one though, I'll do some searching online and see what I can find.

Thanks for the suggestion!

How many clipping options do you want?

[Guybrush]

I was thinking of doing a three way switch:

1 - Standard Rat with 1N4148 diodes
2 - No clipping
3 - Turbo Rat with 3mm red LEDs

Would that be doable?

[benny_profane]

Definitely. Use an On / Off / On DPDT switch.  Connect two anti-parallel 1n4148 diodes to the top lugs and two anti-parallel LEDs to the bottom lugs (you can switch those positions if you want). Wire from one of the diode pads coming from the circuit to a middle lug and wire the other middle lug to ground (you can use the other diode pad that goes to ground for that). Leave the other diode spot on the PCB empty. It should look like this:

[Guybrush]

Thank you so much. That's incredibly helpful and very much appreciated.

I'll give it a go!

Thanks again.

[mwelch]

I built a Rat a few months ago that has 12 different clipping options.  I installed a 12 position rotary switch with different diodes for each one.

My favorite positions are D9E, 1N4001, Red LED, and no clipping, but they all sound good. The Rat is one of my favorite pedals.

Here are the different clipping options I have:

0 – No Clipping
1 – 1N4148
2 – 1N914
3 – 1N4148 (3)
4 – 1N34A
5 – 1N270
6 – D9E
7 – BAT41
8 – 1N4001
9 – Red LED
10 – Clear LED
11 – 2N7000 MOSFETs

Mike 

[jkokura]

Yeah, the rat is one circuit that the clipping diodes really are about personal taste. Just about anything and everything can work, you just need to compensate for volume differences in some cases.

As a pedal user, I prefer circuits to only have a couple choices. 12 different diode options only really leads you to finding which ones you like best, and then leaving it set there. Here's an idea for you - put the diode selector on a stomp switch. Then, instead of bending down and switching the diodes by hand, you can switch on the fly. The key is finding diodes that sound different that allow your pedal to stay around the same volume level.

Jacob

[benny_profane]

Definitely. Use an On / Off / On DPDT switch.  Connect two anti-parallel 1n4148 diodes to the top lugs and two anti-parallel LEDs to the bottom lugs (you can switch those positions if you want). Wire from one of the diode pads coming from the circuit to a middle lug and wire the other middle lug to ground (you can use the other diode pad that goes to ground for that). Leave the other diode spot on the PCB empty.

Also, since you're including LED clipping, you can replace the op amp clipping (no clipping) with another diode option if you'd prefer.

Use the same DPDT switch, but put the anti-parallel LEDs across the two center lugs so that the wires and the LED leads are connected to the same lugs. Solder your new clipping options in the spot where the LEDs were. The LEDs will always be in the circuit, but as long as the Vf of the other diode option you choose is lower than that of the LEDs (e.g., 2x1 asymmetric silicon is my favorite here), they will conduct before the LEDs do. I think that the op amp clipping is rather harsh with the Rat, so that would be my personal solution here.

[Guybrush]

Thank you for all the feedback and info. There's a lot for me to get my head around but I'll give it a go for sure.

Also, since you're including LED clipping, you can replace the op amp clipping (no clipping) with another diode option if you'd prefer.

Use the same DPDT switch, but put the anti-parallel LEDs across the two center lugs so that the wires and the LED leads are connected to the same lugs. Solder your new clipping options in the spot where the LEDs were. The LEDs will always be in the circuit, but as long as the Vf of the other diode option you choose is lower than that of the LEDs (e.g., 2x1 asymmetric silicon is my favorite here), they will conduct before the LEDs do. I think that the op amp clipping is rather harsh with the Rat, so that would be my personal solution here.

Thanks so much for this. I really like the sound of this. Is there any chance you'd be willing to make up another diagram like in your earlier post to show me how it all would fit together?

Thanks again!

[benny_profane]

Thanks so much for this. I really like the sound of this. Is there any chance you'd be willing to make up another diagram like in your earlier post to show me how it all would fit together?

Thanks again!

I pulled that photo from the web. I think I have an easier suggestion anyway.

There will be two diode positions for clipping on the board. For one position, solder in anti-parallel LEDs (there will be two leads going into each hole). These will always be in the circuit. From the other position, wire it up like the diagram posted before, but install another clipping option instead of the LEDs. That's it!

[Guybrush]

That's great thank you!