ROG Tonemender plus boost build

[Ronan]

I've had a lot of fun with this build, its very versatile and effective, so thought I would share.

I built it into a joyo ultimate octave box, using the existing joyo footswitches and their PCB's and LED's. I have an old amp from the late 1960's which has baxandall tone controls, which when set flat, seem to give a flat freq response, so I use the Tonemender to scoop the mids a bit and fine tune the bass and treble.

The boost part is a mod and to do that I put an LDR in parallel with the 4K7 resistor that sets the gain for U1b (the ratio of the 4K7 and the 500K level pot sets the gain). I used a 200K pot in series with a 22K resistor to feed 9V to the LED facing the LDR inside the black heatshrink. I can have the Tonemender running and hit the boost footswitch for a pre-dialled boost, for a lead solo for example.

Tonemender schematic



Sorry 'bout the graphics - I'm working on that, truly I am (yeah right...)

A gut shot here and another one.

The Tonemender is an example of a simple circuit that works really well, that you can't buy as far as I know, and has many uses, for example eq, boost, eq with boost, vol cut, overdrive with eq, or as a clean preamp to drive a poweramp.

[B Tremblay]

I quite enjoy the bare-bones graphics.  The opto-powered boost mode is a very elegant implementation. Well done!

[Bill Mountain]

I think I get the LDR setup but could you explain why you did it that way?

[Ronan]

Thanks for the compliments Brian.

I think I get the LDR setup but could you explain why you did it that way?

It's the easiest way I could think of, and no switching noise. If you have any suggestions though, I'm all ears.

[Bill Mountain]

I might have used a switch to swap the 4.7k resistor and a 5k pot.  I'm no expert and the thought of using an LDR scares me so I never would have considered it.

[reddog22]

Very nice

[Elijah-Baley]

I might have used a switch to swap the 4.7k resistor and a 5k pot.

Old topic, but I'm really interested in this mod. I would like to give at the Tonemender a gain pot control. Do somebody knows how it sounds.