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Forum Home > Layout Gallery - GuitarPCB Build Documents, Mods and Tips > Roto-Tone by GuitarPCB

Site Owner
Posts: 8793

The Amazing Roto-Tone - Layout by Bruce R.

This valuable tool allows pedal fanatics to reach new levels of creativity!

Now it is possible to add multiple mods to your favorite effects!

This compact switch and board combination gives you the ability to change out 4 different tonal combinations with a simple quick turn of the dial.

Here is what we have designed the board to accommodate:

  • Select different combinations of diodes to provide new tonal pallets
  • Change capacitors to select different tonal responses or speed settings
  • Change out resistors to modify gain settings, volume levels or tones
  • Modify both resistors or diodes and capacitors at the same time
  • Trimmers - 6mm and Cermet both of which we carry
  • Sockets! Yes you can socket everything

Among the best features is the small size! The board with switch included is smaller than a typical stand-alone 2P4T switch available at most outlets. This means even in the tightest builds this handy Modder Tool will "float" above many other components inside your enclosure. It is also small enough to fit easily on the side wall of a 1590B as well. 8)

So many Mods are available that we will start dreaming up as many as we can and put together a special PDF guide with some of our favorites. You can help us do that if you wish!

Will update as Mods come in.


Available in the PCB Shop

Get your Mod on...

February 26, 2016 at 6:50 PM Flag Quote & Reply

Posts: 35
Yay! I thought we were gonna have to wait till Monday. I saw the notice in my email and immediately logged in and ordered three! Can't wait to put these to use. Ultimate mod-board, yes please! Thank you!

Building and occasionally selling as "Daddy Daughter Pedal Works" Not attempting to start a second job, just having a good time with my kid and looking to have a self-funding hobby.

February 27, 2016 at 1:20 AM Flag Quote & Reply

Josh X
Posts: 1

Am I correct in thinking that I could optionally use a 1P4T rotary for A and another for B? Kicking in to mad scientist gear here.

I think I need like ten of these. Ha. Switchable wah caps. Switchable caps in tone stacks. Clipping options. LFO range switches.

Idea for a future revision: Include pads for pop resistors jumping the switch positions (ie Varitone).

Of course one could simply bypass the pedal to switch if a slight pop would ever be an after effect for any specific mod.

February 27, 2016 at 6:59 PM Flag Quote & Reply

Site Owner
Posts: 8793

Mod Ideas:

Replace (1) Bias trimmer with (4) Preset trimmers in any Fuzz and switch between Nasty Fuzz, Smooth or anything in between. One of many examples to explore. Here are some more common ideas to try:

  • Change out resistors to modify gain settings, volume levels or tones!
  • Change capacitors to select different tonal responses or speed settings!
  • Modify both resistors or diodes and capacitors at the same time!
  • Select different combinations of diodes to provide new tonal pallets!
  • Route signals to different destinations!


The possibilities are endless! It is all up to your imagination and desires!

When replacing a single section on a board where clipping diodes are located (check the schematic) and if our board does not already have A/B pads then simply replace the clipping section (leaving it empty) on the main board which is now replaced by the (4) options on the Roto-Tone.


Did you know that many of your favorite effects may have several possible ways to modify their characteristics? In many cases, simply changing a few components can provide new tones with a single turn of the switch!


The tonal possibilities are all up to you. Take your pedal building to new levels of creativity! Try adding additional sounds to your favorite effects pedals!

Share your ideas which may be added here! Use the Pedal Discussion section of the forum.

As shown below any of our circuit boards with A/B Pads can be used in the same manner.

Boards without A/B pads can also be used (see ColorTone Supa Fuzz Tonebender below)

February 28, 2016 at 11:22 AM Flag Quote & Reply

Site Owner
Posts: 8793

More diagrams & ideas courtesy of Tonmann, Wilkie1 and PeteV etc...

This photo shows orientation depending on the side of the board you put the switch on.

Thank you PeteV. :)

This photo shows a typical clipping option mod on a circuit that does not have A/B pads.

Compare this with the schematic from the Build Document. Thanks Wilkie1 :)

This photo by Wilkie1 is based on Tonmann's Diagram using (2) Roto-Tones as Circuit Switching tools.

I suggest you "Right Click" and "Save As" - PC to download a High Res image that you can Zoom In on.

Thanks to Tonmann for the great idea of a circuit switcher & Wilkie for drawing the wiring guide. :)

Another Roto-Tone guide for our upcoming board called the Killer Bee.

Hopefully these will help when comparing with schematics and applying in other situations.

Threads with other Roto-Tone Questions:

May 15, 2016 at 11:29 AM Flag Quote & Reply

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