Schematics/Parts List for a 3 band EQ pedal

[S J B]

Hey Guys,

 

I wanna build a really simple and small 3 band/knob EQ pedal. Just Treble, Middle, and Bass. If absolutely necessary, I would add a Level/Volume if absolutely necessary.

 

This would be in a small enclosure (as small as possible, say 1 inch x 3 inches) and used to after overdrive/distortion pedals without great EQ controls.

 

Any links to schematics, diagrams, parts lists for a simple DIY project?

 

Thanks in advance for sharing.

 

Cheers

SJB

[WRGKMC]

First question would be, do you have any electronic skills.

Second are you doing this for pleasure to learn, or actually want something useful.

Third would be would you mind paying 2X~4X the ammount on a bild vs just buying something built.

 

I ask this because many dont realize that building a single unit doesnt equate to any kind of savings or quality.

For the price of the parts in a cheap build you can buy a much higher quality unit built already. If your goal is end results

building your own isnt the way to go. If your goal is to learn, its better to learn then build.

 

Manufacturers buy parts in huge parts quanity with bulk wholsale pricing. An op amp for them may only cost 20 cents.

For you buying one may cost $10.

 

Electronic tech types/hobbiests often canibalize old equipment to get parts and save on the cost of building gear.

They only buy things they absolutely need to and even then they usually have a number of sources

for buying cheap depending on what they need. guys like myself even build their own box from scrap metal so I dont have to shell out

$10 for a chunk of metal. Buying old damaged boxes on auction sites for peanuts is another way of getting cases.

 

So if your'e interested in building from scratch those are things to take into consideration.

If it isnt a kit, you also have to design your own PCB boards to mount the parts. Again if you dont have the skills to think it through

you might want to think about a computer program that will help you there. Then you also need the basic tools, Soldering iron, multimeter etc.

 

Heres some options.

You can do a half build which is still cheaper.

Just get one of these and stick it in a box and add a dpdt switch to kick it off and on.

I've put several these in instruments and they are high quality EQ's with good musical tone.

http://guitarfuel.com/3_Band_EQ_Harness.php

 

Heres another

http://cgi.ebay.com/THREE-BAND-EQUALIZER-KIT-AND-PICKUP-GUITAR-9030-/220550857003

 

And another http://www.amazon.com/Koss-EQ50-3-Band-Stereo-Equalizer/dp/B00005UPF6

 

 

Another option is to just buy one of these. You can pick them up for $20 all day long.

http://cgi.ebay.com/Behringer-EQ700-Graphic-Equalizer-Effects-Pedal-NEW-/250791586226?_trksid=p4340.m185&_trkparms=algo%3DSIC.OPJS%26its%3DI%26itu%3DUA%26otn%3D5%26pmod%3D270746853779%26ps%3D63%26clkid%3D2083434633952338497

 

If you want to do a kit (which is what I recomend for beginners) heres one.

http://www.analogmetric.com/goods.php?id=1118

it probibly isnt instrument level so you will need to learn how to modify the input and output impedances.

 

If all you want is a schematic this one looks fairly simple.

http://courses.cit.cornell.edu/bionb440/FinalProjects/f2005/asa27/ASAfinaldemo.htm

Again its likely line level and needs modification to work with a guitar.

[m-theory]

Not 3 knobs, but very effective, very simple, and very cheap:

http://www.beavisaudio.com/techpages/BigMuffToneControl/

 

You could also build a simple Fender or Marshall tone stack, although you might want to put a simple boost in front of it.

 

http://www.ampbooks.com/home/classic-circuits/bassman-tonestack-intro/

http://www.runoffgroove.com/oldfetzer.html

http://www.muzique.com/schem/mosfet.htm