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OD circuit as onboard active control

Started by mandrewbot3k, February 02, 2015, 08:04:34 PM

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mandrewbot3k

Anyone ever see or use an overdrive circuit as an onboard active tone control? I've got a vero timmy that would go well in on of my upcoming tele builds. Also have a kingslayer and fatpants that could work well. Other than committing to the effect on the guitar, Anyone ever see something like this? I keep my timmy on all the time anyways.

I could just use a push pull or even dual gang volume control for active/ passive.
Andrew

(Formerly roflcopter)

Muadzin

#1
I think these are usually called 'preamps'.  :P

Seriously though, if you want to do this, go ahead, seems doable. If it were me I would go for a dual gang for volume control on both the passive and the OD circuit and I would use a 3PDT toggle switch to switch between passive and active. And wire it as such:
1. passive send   4. passive return  7. nothing
2. input from pickup selector  5. output to output jack  6. ground connection
7. to OD board   6. from OD volume pot   9. ground sent to OD board.

The reason for this is so I would hook up the ground connection from the jack to lug 6 of the switch. I would connect the passive volume pot to lug 6 as well so as to complete the classic ground connection as is in almost any guitar. By connecting the ground of the OD circuit to lug 9 I would make sure the circuit only becomes active when in use. Otherwise with a simple DPDT bypass switch or the push pull pot the circuit would still be active and draw power when bypassed as long as the guitar is plugged in. Thus conserving battery life. I've done this in one of my own guitar which has an internal fuzz circuit.

Also, use easily accessible trimpots any control on the board which is not directly accessible on the outside.

mgwhit

Check out the Ibanez Tube Screamer amp for an example of an amp with integrated overdrive effect.  I think an OD with a flatter response or more tonal options would be better suited for what you're talking about.  Also check out schematics for certain JCM 900 models. Those definitely integrate op amps and clipping diodes for overdrive, although I can't remember how they implement the tone stack.

mandrewbot3k

Quote from: Muadzin on February 03, 2015, 07:04:49 AM
I think these are usually called 'preamps'.  :P

Seriously though, if you want to do this, go ahead, seems doable. If it were me I would go for a dual gang for volume control on both the passive and the OD circuit and I would use a 3PDT toggle switch to switch between passive and active. And wire it as such:
1. passive send   4. passive return  7. nothing
2. input from pickup selector  5. output to output jack  6. ground connection
7. to OD board   6. from OD volume pot   9. ground sent to OD board.

The reason for this is so I would hook up the ground connection from the jack to lug 6 of the switch. I would connect the passive volume pot to lug 6 as well so as to complete the classic ground connection as is in almost any guitar. By connecting the ground of the OD circuit to lug 9 I would make sure the circuit only becomes active when in use. Otherwise with a simple DPDT bypass switch or the push pull pot the circuit would still be active and draw power when bypassed as long as the guitar is plugged in. Thus conserving battery life. I've done this in one of my own guitar which has an internal fuzz circuit.

Also, use easily accessible trimpots any control on the board which is not directly accessible on the outside.

Good Info!
I haven't noodled it all out yet. I was planning on using a stereo jack and running in 9V on the ring. so its only ever active with an injector at the pedalboard. The more I think about it, the less I want to do it. haha.

Quote from: mgwhit on February 03, 2015, 08:18:38 AM
Check out the Ibanez Tube Screamer amp for an example of an amp with integrated overdrive effect.  I think an OD with a flatter response or more tonal options would be better suited for what you're talking about.  Also check out schematics for certain JCM 900 models. Those definitely integrate op amps and clipping diodes for overdrive, although I can't remember how they implement the tone stack.

I was thinking onboard the guitar itself, not on the amp.
Andrew

(Formerly roflcopter)

mgwhit


mandrewbot3k

Quote from: mgwhit on February 03, 2015, 08:57:41 AM
Sorry. Should have read more closely.

No worries! I just responded because I didn't want you to feel neglected  ;)
Andrew

(Formerly roflcopter)