New at runoffgroove.com: Tonemender

[B Tremblay]

The Tonemender is a clean boost with an ultra-flexible tonestack. Check it out!

Article, schematic, and PCB/perfboard layouts: http://runoffgroove.com/tonemender.html

Sound clips and photos to come!

[electrictabs]

you did it again
COOL!!!

[Dragonfly]

very cool....

thats quite similar to the 386 based boost with hi and low eqs, and mid boost switch that i'll be posting a layout for...yours is a bit more "in depth", however...

gonna have to build this one !

[jimbob]

As always - another awsome build from ROG! Cant wait to giver a try!

thanks guys!

[GreenEye]

I bet that would work great with some of my tube PAs that only have one little knob for tone control....

[vseriesamps]

Definitely going to build this. Thanks so much. Your stuff is always great.

K

[ninoman123]

Bow down to the all powerful ROG!!!! I checked out the schem, looks awesome man!  

[Marcos - Munky]

Cool!!! I'm waiting to hear some soundclips of it.

[petemoore]

Good one, a box like that could see alot of uses !!!

[onboard]

You guys just don't quit, huh?  :wink:  

Nice job!

Funny because before I looked at this thread I was over in the guv'nor thread and thought "Hey, why not do some switching with the tone stack caps..."

(insert spooky theramin)

[javacody]

OK, finally, a pedal that can make my crappy tube amp hopefully sound somewhat decent.  

I wonder how this would sound into a speaker sim and into my pc?

[petemoore]

I was looking that over again today...pretty slick...how you got 'that in there...gotta love that mids switcher.

[Mark Hammer]

If it weren't slick enough, over 20 years ago, Steve T-Boy Morrison, who operates AMPAGE (and the Firebottle "empire" too, I gather) published an article in Polyphony magazine (that became Electronic Musician under the same editor - Craig Anderton) outlining a tone-bypass mod for Fender amps and other amps possessing the same sort of tonestack.  Even though no amp is involved, the mod is applicable here too, so I'll mention it again.

The tone stack works by selectively bleeding frequency content to ground, relative to what it "bleeds" to the output and next stage.  ALL the "bleeding" to ground goes through a final common pathway.  In the case of the classic Fender tonestack, it is either a 6k8 fixed resistor to ground (if the amp has a simpler treble/bass tone complement) or through a 10k pot (if the amp has the more complex treble/mid/bass complement).  Lift the ground connection of that resistor or pot, and the tone controls become essentially ineffective, with little audible tonal variation resulting from rotating the controls.  At the same time, in the absence of any bleeding to ground, there is a noticeable level boost.  Note that this is NOT a true boost, merely a resumption of whatever gain/level was coming out of the preceding gain stage.

I did the mod to an old blackface Tremolux I used to own and quite liked it.  Great for going from a thinner tone to a beefy one.  As you can imagine, getting both a level boost AND a simultaneous "de-scooping" ends up pushing subsequent stages in the amp harder with more distortion resulting.  Excellent for a variety of solo tones.

The same strategy can be applied here by simply wiring up the ground (Vref) end of 100k midrange pot and the parallel 100k resistor to a SPST switch, and the switch to Vref. That could be a toggle, or if you felt like having a dual stompswitch box, a DPDT stompswitch with LED indicator.

Remarkably simple.  Remarkably effective.

If you find the jump in volume or change in tone is unappealing with the mod as described, there is no reason why you could not find a resistance to ground in between open circuit and the parallel resistance of the 100k pot and 100k resistor.  To do this, stick a 500k to 1meg pot, wired as variable resistor between the Vref end of the midrange pot and 100k fixed resistor, and dial in the amount of "de-bleeding" you want.  The extra toggle or stompswitch then is used to shunt the added pot so that the tone-bypass/boost switch varies between the normal action of the tone stack, and whatever degree of tonestack defeat you have dialed in.

Even without such a mod, the ROG team comes up to bat and hits a standing triple every time.  Well done.

[Torchy]

ROG Tonemender [url]

[Torchy]

oops - try again  :oops:

ROG Tonemender

[octafish]

Damn Torchy, slow down or you'll do yourself an injury. Soon you'll be doing vero layouts for circuits that haven't even been drawn yet!

[B Tremblay]

A photo of the populated perfboard has been added to the page:
http://runoffgroove.com/tonemender.html

Currently working on a sound clip...

[Alpha579]

Great! i love seeing that 'new at runoffgroove:'...thx  

[Ken]

G'day all

re: Tonemender........

Just wanted to confirm that Thorchy's vero works

no problems.

ROG this is a Freaking great pedal.

Cheers Ken.    

[Torchy]

Mine's a keeper ...