Good EQ Pedal Build?

[Arn C.]

Anyone know of a good eq to build?

Thanks!
Arn C.

[Aharon]

Jay Doyle had one I think but I haven't heard of him or his stuff for ages now.
Aharon

[Thomas P.]

look over at geo. R.G.'s got some really good informations about it.

[David]

Arn:

In the next couple of weeks, I'm planning to build a boost / EQ pedal based on the clean boost and EQ stages from the "Pocket Rockit" at Hammer's site.  Maybe this would work for you.

[Aharon]

I've been toying with the idea myself,mainly to implement it for my EQ Screamer but I build so much crap that I have no time for my own designs,
I should do it already and get it over with.(lol)
Aharon

[Mark Hammer]

Q#1: What do you want an EQ pedal to do for you?

Most EQ pedals are designed without any particular use in mind.  As a result, the resonant frequencies are simply equally spaced in anticipation of....whatever, and not optimized for anything in particular.  There is no regard for what bands are most important for reshaping the character of a particular instrument with the least futzing possible, and no real sense of mission.  Moreover, they are designed in an all-or-nothing manner.  That is, there are no EQ pedals that let you tweak, say, the extremes of the frequency spectrum and enable/disable changes in the middle via footswitch, while retaining the upper treble/lower bass adjustments.

So here is the preferred EQ pedal.

1) A bass/treble shelving EQ, with turnover frequencies spread fairly far apart (i.e., 200hz and 8khz)

2) A tunable 2-pole lowpass filter with resonance control.

3) Two bands of almost-parametric EQ (Q control is optional).

Each of these are independently switchable and the whole shooting match is capable of global bypass.  The bass/treble shelving lets you adjust in order to compensate for speakers,  or guitar.  The lowpass lets you reduce hiss and/or emulate  different speakers/pickups.  The parametric lets you dial in specific resonances or dial out wolftones or feedback frequencies.

The whole thing comes in at 8 pots (treble, bass, filter-freq, filter res, centre-freq * 2, cut-boost * 2) and 3 switches (global bypass, filter-bypass, parametric-bypass).  There are cookbooks for these circuits posted everywhere.  The parametric sections are nicely laid out in the EQ-ing document at www.geofex.com.

If someone wanted to whip up a layout for this swiss-army-knife EQ, I think they'd whip up a whole lot of friends in the process.  This is something you simply can't buy in any music store.

[Arn C.]

thank you all for the input!!!!
Yes, it would be nice if someonw culd make a schematic of what you described Mark.

I would be one of those friends!!!!!

Arn C.

[Jay Doyle]

Jay Doyle had one I think but I haven't heard of him or his stuff for ages now.

Yikes, I do post now and again, but not as much as I used to.

The EQ in question is the Timbre Box, it's schematic is  here.

R.G.'s formulas in his article that have to do with gyrator/sim. inductor resonant frequencies apply.

It is a discrete opamp that is set up like the Tube Screamer tone stage but the cap on the wiper of the tone pot is replaced with a cap/gyrator combo that allows you boost and cut for the resonant frequency of the cap/gyrator combo.

Hope this helps.

Jay

[Arn C.]

Thanks a bunch Jay!!!!!
     
Arn C.

[Aharon]

Hi Jay,sorry man,I must've missed you when you posted.
You got a bunch of good designs and should have a little site somewhere where they can be enjoyed all at once(lol).
Glad to hear from you
Aharon

[Jay Doyle]

Hi Jay,sorry man,I must've missed you when you posted.
You got a bunch of good designs and should have a little site somewhere where they can be enjoyed all at once(lol).
Glad to hear from you
Aharon

Thanks for the compliment! If I only had the time to work on a web page! :?

I have been working on stuff off line that may make it to the web eventually, but I started to realize after spending a lot of time here that I wasn't coming up with my own ideas, just modding other people's so I stepped back and "worked for myself" so to speak.

I try to pop in now and then to answer some stuff...

Regards,

Jay