EQ options on a pedal

[Natman]

Hi all, I have been wondering if it is relatively simple to add some EQ options in one of my guitar pedals. I was inspired by this guy: https://goo.gl/images/8TQQay

It essentially uses a 5-position varitone for its tone knob. I have used one in the past and even added it into an enclosure so it could be used as a pedal. I'd like to do that again but wonder if it's better pre gain or post gain?

On a side note I've ordered an Artec QTP passive varitone, a compact unit made in China with SMT parts. This is what I intend to test out, with and without inductor.

I've also wondered about how I could get a midrange pot to do the same thing. Guitars all have tone pots which only cut highs and that's pretty limited. I started adding passive midrange on my guitars and love it.

So that's 2 passive EQ shaping tools I'd like to test in an enclosure but I'm kind of a newb so not sure how to implement this. They could be incorporated into a boost/buffer pedal to compensate for the loss of filtering since I believe that's how active EQs work but again not sure how to implement it...

Thanks for your input!

[Enzo]

Get a cheap Danelectro EQ pedal and try that. Boost and cut. or just clean boost across the board. Try it between guitar and amp, and then try it in the FX loop. Lots of fun for not a lot of money.

[Mark Hammer]

You need to identify what pedal you are talking about.

Many pedals employ different cap values to limit bandwidth in strategic ways. A perfect case in point is the venerable TS-9 Tube Screamer, which deliberately shaves off the low end before clipping and the high end after clipping to achieve a characteristic sound, Many of the TS-9 derivatives that followed, since 2005 or so, played with those cap values within the same basic design to achieve different sounds.

'Tis a simple matter to install toggles (assuming space permits) to vary cap values in specific planful ways, that will do much of what you want, without having to change the design at all.

[Mick Bailey]

I use digital switching in my varitone pedals with separate up/down foot switches and a digital display. The tone part of the circuit is analogue, with just a bunch of caps, an inductor and anti-pop resistors. I have 8 varitone selections, straight through and preamp-only, so 10 positions in all. There's a preamp section in front of this with variable gain and level controls that go from clean to grit. This compensates for any loss of signal through the passive section. I found the varitone works better after any boost or drive. Varitone acts as a midrange notch filter in the intermediate positions, as well as treble cut/bass cut at the extremes.

[rjb]

Kibbitzing

Get a cheap Danelectro EQ pedal and try that....

A $20-27 Fish and Chips would be a cheap and easy way to go, but it seems to me that the 1 octave/band controls would be too wide for Natman's goal. I'm thinking a sweepable notch filter or parametric eq, like a single control from a mixer with sweepable mids, would be closer to what he's looking for.

Commercial parametric EQ stompboxes are available (for considerably more $ than a F&C), but I have no experience with them. Here are some refs.
5 Parametric EQs for Precision Tone Sculpting | Tone Report
Simple, Easy Parametric and Graphic EQ's, Plus Peaks and Notches
https://buildyourownclone.com/products/paraeq

-rb

[Natman]

This compensates for any loss of signal through the passive section. I found the varitone works better after any boost or drive. Varitone acts as a midrange notch filter in the intermediate positions, as well as treble cut/bass cut at the extremes.

This is the kind of thing I have in mind, not an eq pedal per say. I want to build a varitone into a separate box at the beginning or end of my pedal board. I also have a Barber Launch Pad that is an excellent clean boost and a candidate to counter the losses of passive controls.

[bob p]

Regarding the cheapo Dano EQ pedal -- I've got a bunch of them. I think they're pretty useful for signal shaping before/after distortion and in an FX loop. that said, they'll never match the utility of a 3-band/octive EQ or RC filters that are chosen for a specific frequency cutoff, but they're a cheap plug-n-play solution.

[Enzo]

I was thinking even if the EQ pedal isn't the solution to the problem, it is cheap and quick and trying it before and after and experimenting might be illuminating of your needs. It might expose some things you may not have considered.

[Gnobuddy]

A $20-27 Fish and Chips would be a cheap and easy way to go

The Danelectro Fish and Chips is the most useful guitar pedal I have. So much so, that I now have three of them. One is permanently preset for use with my Yamaha electro-acoustic guitar, to make it sound good through the P.A. system. A second one is usually used with whatever electric guitar I'm playing that day. The third is a spare, in case one of the others dies. Actually I bought it when one of the others did die, but I subsequently managed to resuscitate it.

I have only one real criticism of these wonderful little pedals - the input and output jacks are inconveniently close to each other, so those flat-headed short patch cables won't fit. Annoying, but not a show-stopper!

-Gnobuddy

[Mick Bailey]

If you're looking to build a varitone + mid control into a pedal, then I'd go for a 12 position switch for the varitone. The inductor is an important aspect - don't know what the Artec circuit uses and it would be interesting to know if this is anything other than a bunch of tone caps and a pot. Some vendors are selling just that and claiming it as being a Varitone circuit. Because you have space inside a pedal you can also incorporate a depth control to vary the notch depth, or if you use a miniature transformer as the inductor (I do) then select either half the winding or the full winding as per Craig Anderton's design.

The Snarling Dogs Very-Tone pedal is a useful reference for a 'compensated' Varitone ( you need to register to see the pics);

freestompboxes.org ? View topic - Snarling Dogs Very-Tone Dog