Hey, New to working on pedals.
Would it be possible to rehouse a Boss GE-7 or similar basic eq pedal in a larger enclosure, and replace the stock faders with larger ones? I'm thinking of creating something similar to a DOD 606, or a Boss GE-10 but with 6 or 7 faders instead of 10.
I'd also like to add two mods to the circuit.
1) Guitar/Bass mode.
- is it possible to modify the circuit so that a toggle switch changes the frequencies of each fader to a different value. for example if on "Guitar mode" the lowest Fader would amplify 100hz, but when on bass mode, that fader would alter 32kz.
2) Notch filter
One of my favorite pedals of all time is the L.R. Baggs Align Equalizer. It has an awesome notch filter that allows you to instantly find and remove a tone that is causing you guitar to feed back. I'd love to add the same filter to this pedal
How much work is this for a starter project? I'm a little unsure where to start. Any suggestions?
Welcome!
Graphic EQs, even re-houses, are a LOT of work.
You can buy big graphic EQs at the used music gear shop, no?
This Link (https://www.musiciansfriend.com/search?typeAheadSuggestion=true&typeAheadRedirect=true&isTypeAheadSearch=true&Ns=r&tAt=term&tNtt=graphic%20equalier&tAv=graphic%20equalizers&Ntt=graphic+equalizers) is mostly new gear (altho there's a screaming-good used deal at the end). Anything new eventually ends up in the "preowned" section. GEQs have not changed much in decades. (Except BeeRinger's prices are insane...)
Quote from: RacoonChrist on June 07, 2021, 07:09:17 PM
I'm a little unsure where to start.
Start here: http://www.geofex.com/article_folders/eqs/paramet.htm
Then you should notice the GE-7 uses six gyrators as described in the article:
(https://www.hobby-hour.com/electronics/s/schematics/boss-ge7-equalizer-schematic.png)
Changing the center frequency implies changing a resistance (per band), so your mods would need a six or seven-pole switch (probably CMOS rather than mechanical) for (1), and a potentiometer (maybe on a SPDT switch) for (2).
Quote from: FiveseveN on June 08, 2021, 02:54:37 AM
Quote from: RacoonChrist on June 07, 2021, 07:09:17 PM
I'm a little unsure where to start.
Start here: http://www.geofex.com/article_folders/eqs/paramet.htm
Then you should notice the GE-7 uses six gyrators as described in the article:
(https://www.hobby-hour.com/electronics/s/schematics/boss-ge7-equalizer-schematic.png)
Changing the center frequency implies changing a resistance (per band), so your mods would need a six or seven-pole switch (probably CMOS rather than mechanical) for (1), and a potentiometer (maybe on a SPDT switch) for (2).
the problem with just changing a resistance is that it also changes the Q of the filter, i doubt you want that, you could better change a capacitor.
cheers
Quote from: iainpunk on June 08, 2021, 12:26:58 PM.....the problem with just changing a resistance is that it also changes the Q of the filter, i doubt you want that, you could better change a capacitor....
Two capacitors.
Note that the Rs are all (nearly) the same over many Octaves. The Cs vary about as frequency. The *ratio* of the Cs is meaningful to Z and Q, but painful to compute; just change them together.
(https://i.imgur.com/AmzoLC1.png)
Just replace GND with Vcc/2 and -12 with GND..
Quote from: FiveseveN on June 08, 2021, 02:54:37 AM
Quote from: RacoonChrist on June 07, 2021, 07:09:17 PM
I'm a little unsure where to start.
Start here: http://www.geofex.com/article_folders/eqs/paramet.htm
Then you should notice the GE-7 uses six gyrators as described in the article:
(https://www.hobby-hour.com/electronics/s/schematics/boss-ge7-equalizer-schematic.png)
Changing the center frequency implies changing a resistance (per band), so your mods would need a six or seven-pole switch (probably CMOS rather than mechanical) for (1), and a potentiometer (maybe on a SPDT switch) for (2).
Amazing. Thank you.