How would I add 5mm red LED to a Rat 2 to make it "Turbo RAT" spec?

[Barnshart]

I have a proco RAT 2, I have 5mm red LED's and a believe a DPDT on/on switch. Is that all I need to insert some red LED clipping to the pedal? If so, could somebody either show me a diagram to add the switch & LED's into the pedal, or point me to a link / video covering this.

Or am I missing something entirely to make this mod work?

Thanks in advance to anybody who helps out!

 

[Feral Feline]

IF all I had was the on-on switch and 2 LEDs...

I would remove the existing clipping diodes and from one of the empty diode spots coming off the signal path then run a wire to the switch's lug #2:

1 4
2 5
3 6

Then I'd take the original diodes and attach them anti-parallel between lugs 3 and 6.
The LEDs I'd run anti-parallel between lugs 1 and 4.
I'd then run a wire from Lug-5 to ground.


Done.

Gives you STOCK clipping in the up position and LEDs in the down position.


What I'd prefer to do is only slightly more involved.

Using an on-off-on switch wired as above, the middle toggle would give you a no diode-clipping option — some people really dig the Rat when it's just the op-amp hitting its rails and clipping.

If you take the same on-off-on switch and wire the LEDs across lugs 2 and 5, and put another set of diodes (overall forward voltage being less than the LEDs), then you'd have STOCK, LEDs (Turbo), and whatever the third set of diodes you selected.


There will be volume differences when switching between the diode flavours so you'll need to adjust LEVEL and possibly even GAIN to compensate.

There is plenty of info available online regarding this simple mod, if you need more info I can point you to some.

 

[Barnshart]

IF all I had was the on-on switch and 2 LEDs...

I would remove the existing clipping diodes and from one of the empty diode spots coming off the signal path then run a wire to the switch's lug #2:

1 4
2 5
3 6

Then I'd take the original diodes and attach them anti-parallel between lugs 3 and 6.
The LEDs I'd run anti-parallel between lugs 1 and 4.
I'd then run a wire from Lug-5 to ground.


Done.

Gives you STOCK clipping in the up position and LEDs in the down position.


What I'd prefer to do is only slightly more involved.

Using an on-off-on switch wired as above, the middle toggle would give you a no diode-clipping option — some people really dig the Rat when it's just the op-amp hitting its rails and clipping.

If you take the same on-off-on switch and wire the LEDs across lugs 2 and 5, and put another set of diodes (overall forward voltage being less than the LEDs), then you'd have STOCK, LEDs (Turbo), and whatever the third set of diodes you selected.


There will be volume differences when switching between the diode flavours so you'll need to adjust LEVEL and possibly even GAIN to compensate.

There is plenty of info available online regarding this simple mod, if you need more info I can point you to some.

So maybe a dumb question. But when I open up my RAT and take out both diodes that are currently there, is one half of the diode going to ground on that's PCB? How do I know which is ground?

I already pulled it apart and decided I prefer LED's in there so thats what I've got in now. But the diagram you gave with the on / off / on sounds very interesting to me. I just don't know where lug 5 goes to be connected to ground on the PCB.

Hope my confusion makes enough sense to answer! Thank you!

 

[Feral Feline]

All good. We all started this journey with one small solder-step...

Forgive me if I get too basic, as I don't know where exactly you are on your path.


Do you have a Digital Multi-Meter? Even the most basic ones should have a "BEEP" mode. Get your DMM and set it on Batfink's "BeeP!", otherwise known as testing continuity.

Sometimes the dial on the DMM also has a diode symbol with beep mode — this one has a soundwave, Ω, and diode :

(if you didn't already know it, you've learned your first schematic symbol)

So with your DMM on continuity-beep mode, place one of its probes on a known ground point such as the GND-lug on the DC-jack or on the PCB pad that comes from the DC-jack's GND wire,
now place your other probe on the circuit board where the diodes are and poke at each of the four points the diodes contact the board — your DMM should beep for two of the four points — note which ones they are, that's where you can run a wire from the switch's lug-5 to either GND point formerly occupied by a diode.


I just watched some of the video I posted earlier (I had never watched it before) — dude was complicating things beyond what's needed with four wires to two wires to ... well I assume to the switch, as that's where I stopped watching. You need just one wire going to the switch from the signal path (either of the two diode pads on the PCB that were NOT GND, and one wire from the switch to GND.

When I built my Filligree Siberian Hamster, I went for the on-off-on switch trifecta of diodes:
Stock 1N914/1N4148,
Turbo LEDs, and
Fat Rat combo of Schottky & MOSFET as diodes.

You could stick germanium diodes in place of the stock or Fat Rat diodes for the You Dirty Rat, but important point, the LEDs have to be in the middle position. With the switch "off" the LEDs' are in the circuit, but when the switch is toggled either up or down the forward voltage of the other diode set takes over, effectively bypassing the LEDs.

EDIT: fixerd a typo

 

[Barnshart]

All good. We all started this journey with one small solder-step...

Forgive me if I get too basic, as I don't know where exactly you are on your path.


Do you have a Digital Multi-Meter? Even the most basic ones should have a "BEEP" mode. Get your DMM and set it on Batfink's "BeeP!", otherwise known as testing continuity.

Sometimes the dial on the DMM also has a diode symbol with beep mode — this one has a soundwave, Ω, and diode :

(if you didn't already know it, you've learned your first schematic symbol)

So with your DMM on continuity-beep mode, place one of its probes on a known ground point such as the GND-lug on the DC-jack or on the PCB pad that comes from the DC-jack's GND wire,
now place your other probe on the circuit board where the diodes are and poke at each of the four points the diodes contact the board — your DMM should beep for two of the four points — note which ones they are, that's where you can run a wire from the switch's lug-5 to either GND point formerly occupied by a diode.


I just watched some of the video I posted earlier (I had never watched it before) — dude was complicating things beyond what's needed with four wires to two wires to ... well I assume to the switch, as that's where I stopped watching. You need just one wire going to the switch from the signal path (either of the two diode pads on the PCB that were NOT GND, and one wire from the switch to GND.

When I build my Filligree Siberian Hamster, I went for the on-off-on switch trifecta of diodes:
Stock 1N914/1N4148,
Turbo LEDs, and
Fat Rat combo of Schottky & MOSFET as diodes.

You could stick germanium diodes in place of the stock or Fat Rat diodes for the You Dirty Rat, but important point, the LEDs have to be in the middle position. With the switch "off" the LEDs' are in the circuit, but when the switch is toggled either up or down the forward voltage of the other diode set takes over, effectively bypassing the LEDs.

This makes perfect sense, I will test it out hands on tomorrow morning.

So I have a question about this 3 way selector. Correct me if I'm wrong please.

If I want to go LED/no clipping/Stock diodes I would need a DPDT On-Off-On

But if I wanted to do LED/Germanium/Silicon would I then need an On-On-On switch?

 

[Feral Feline]

Nope.

BOTH would get DPDT On-Off-On
LED/no clipping/Stock diodes you would attach either set of diodes to the outer lugs, for ex:
LEDs between 1 and 4
Sili-stock between 3 and 6
Nothing between 2 and 5, just the wires from and to the PCB.


If you want three sets of diodes, the set with the largest forward voltage HAS to go in the middle:

Germanium between 1 and 4
LEDs between 2 and 5 (and of course wires from/to PCB respectively)
Stock sili between 3 and 6.


If you attach the diodes to the switch as indicated, depending on how you orient the switch ...

UP/DOWN
1 4 Ge
2 5 LED
3 6 Stock Sili

Up-down, on the face of the enclosure TOGGLE UP = Stock, TOGGLE CENTRE = LED, TOGGLE DOWN = Ge
Turn the switch 180º if you want the stock sili on the bottom toggle position.


SIDE-to-SIDE
4| 5| 6|
1| 2| 3|

Left = stock
Centre = LED
Right = Ge

 

[Barnshart]

Okay good to know.

So in which context would soembody want an on-on-on switch then?

I have one in my Hyped Fuzz build and apparently it's type 1 instead of type 2 so it doesn't do what I need it to do.

 

[Feral Feline]

That's a somewhat loaded question, 'cause you can use an on-on-on switch (just about any switch) in a variety of ways.

A good example of on-on-on is for Aion's Halo (Muff) with Boosted/Flat/Scooped mids, or Aion's Fusion which changes out some clipping arrangement.

PedalPCB's Mini-Drive swaps out some diodes AND bypasses an op-amp/tone section...


Re your HYPED FUZZ
If you've already soldered in the Type-1 on-on-on, I would carefully take apart the switch and flip the internal guts of the switch around and that'll turn it into a Type-2.

I've done it, it worked but It's a fiddly endeavour, though much less problematic than having to desolder a switch.

 

[Barnshart]

That's a somewhat loaded question, 'cause you can use an on-on-on switch (just about any switch) in a variety of ways.

A good example of on-on-on is for Aion's Halo (Muff) with Boosted/Flat/Scooped mids, or Aion's Fusion which changes out some clipping arrangement.

PedalPCB's Mini-Drive swaps out some diodes AND bypasses an op-amp/tone section...


Re your HYPED FUZZ
If you've already soldered in the Type-1 on-on-on, I would carefully take apart the switch and flip the internal guts of the switch around and that'll turn it into a Type-2.

I've done it, it worked but It's a fiddly endeavour, though much less problematic than having to desolder a switch.

Could I pick your brain about doing this same 3 way clipping mod but on the PedalPCB Muffin Fuzz.

So I understand the same wiring with the diodes and switches would be the same concept as in the RAT. But the Muffin Fuzz has 2 different sections of diode clipping in the circuit. So.... Do I need to add 2 sperate switches into the Muffin's circuit to do individual clipping on both parts, or is there a way to wire both sections of the clipping to be on a single switch?

 

[Feral Feline]

You could have the clipping all on one switch, a 4PDT on-off-on, for both clipping stages.
(think of it as having two DPDT switches with only one lever for both)

That won't be as versatile as having two separate DPDT on-off-on, but you may want just two or three distinct sounds.


Either way, you can go into Supa/Jumbo ToneBender mode ...

Do you breadboard at all?
You could see which options really flip your switch, and in turn reduce switches on the pedal, save some dosh. Not sure what the price difference is between a single 4PDT and 2 x DPDT. Yet another option is to just have a toggle on the first clipping stage (or just the second).


Some people love tweaking and want all the options, others want things boiled down to what they like and actually will regularly use.

When I started DIY, I used to want all the options because I could, but now I'm beginning to see that minimising option-paralysis can be good, too. I mean, you can fit a LOT of 3PDT stompers on a 1590BB, but how dexterous are your toes? Practicality has a limit. Anyway, a couple toggles is no problem.

You could even wire up a 4PDT footswitch (on-on) to stomp between two flavours of clipping, though there may be a volume difference.
As mentioned, many ways to wire a switch.

It's like 3PDT wiring for bypass, there are a number of ways to do it — after trying a few (or all) of them you'll most likely gravitate to one way of doing it that makes the most sense to you, it becomes your preferred method.

I'll suggest...
1) decide what exactly you want to do, then
2) see if there's a feasible way to do it, and if not
3) revise "1)".

Rinse, repeat.

 

[Barnshart]

You could have the clipping all on one switch, a 4PDT on-off-on, for both clipping stages.
(think of it as having two DPDT switches with only one lever for both)

That won't be as versatile as having two separate DPDT on-off-on, but you may want just two or three distinct sounds.


Either way, you can go into Supa/Jumbo ToneBender mode ...

Do you breadboard at all?
You could see which options really flip your switch, and in turn reduce switches on the pedal, save some dosh. Not sure what the price difference is between a single 4PDT and 2 x DPDT. Yet another option is to just have a toggle on the first clipping stage (or just the second).


Some people love tweaking and want all the options, others want things boiled down to what they like and actually will regularly use.

When I started DIY, I used to want all the options because I could, but now I'm beginning to see that minimising option-paralysis can be good, too. I mean, you can fit a LOT of 3PDT stompers on a 1590BB, but how dexterous are your toes? Practicality has a limit. Anyway, a couple toggles is no problem.

You could even wire up a 4PDT footswitch (on-on) to stomp between two flavours of clipping, though there may be a volume difference.
As mentioned, many ways to wire a switch.

It's like 3PDT wiring for bypass, there are a number of ways to do it — after trying a few (or all) of them you'll most likely gravitate to one way of doing it that makes the most sense to you, it becomes your preferred method.

I'll suggest...
1) decide what exactly you want to do, then
2) see if there's a feasible way to do it, and if not
3) revise "1)".

Rinse, repeat.

Very good information, thank you for that! I think i'll go ahead and do diode lift option in the first set of them and then for the second set I may go LED/No Clipping/Silicon. That should give me plenty of fun options. If I get ambitious I will try to stick that in a 1590xx with a Rat with clipping as well. Thanks again for the help, really means a lot to me!

 

[Nic]

Take a look at the muffin factory. That thing is full of mod switches. You get to see on the schematic what's doing what.