I give up... someone smart do this help!!!

[Ark Angel HFB]

Here is the Xotic AC booster... http://tasel.net/images/Xotic-RC-AC-Booster-Guitar-Effect-Circuit.jpg

I want the EQ section that is the block base around op amp pins(5,6,7).

I started doing this and got in over my depth. please what is "Vref2"? I mean I guess it is power... but what I need to know is what is needed to get the right "Vref2" out of the little bottom right area. is it just a voltage devide with 22k resistors or what...

HELP MY MIND IS MELTING!!!!

[PRR]

> HELP MY MIND IS MELTING!!!!

Stick your head in the ice-bucket.

> what is "Vref2"? ... just a voltage devide with 22k resistors or what...

Yes. See, it's not that complicated. You already figured that 15K+6K8 is just 22K, and you are not using the 6K8 tap.

> I want the EQ section

Cool.... but the input of that EQ is LOW impedance. Worse: varying with frequency and with knob settings. From over 50K to less than 5K. Skipping details: feeding guitar pickup at the R9 C5 junction (even without fuzz-tame cap C4!) will load-down all the highs from the guitar (even the boost will be limited, it loads as fast as it boosts.)

Even when not fuzzing, U1a serves as a useful buffer to drive the tone controls.

Q1 is also a buffer but may not have enough beef to drive the tone control.

For a clean EQ with a little boost and fade-to-zero:

Remove diodes

R6 = zero

R7= 50K Audio pot (12K fixed for unity gain)

R8 = 470

C4= 2nFd

omit the whole R15-Q2 part, connect C9 to R18 to jack

Foo on that Vref1 tap, Q1 can eat Vref2 perfectly well.

Now everything is buffered. R7 about "6" gives unity gain. Full-up gives a boost that might be useful, full-down is dead, and good spread around unity-gain to compensate gain/loss in other parts of your patch. At max-gain C3 holds frequency response to 22KHz so you don't get supersonic troubles.

WTH is a 4557D? A one-off 4558? TL072 would be a fine amp here.

[Ark Angel HFB]

> HELP MY MIND IS MELTING!!!!

Stick your head in the ice-bucket.

> what is "Vref2"? ... just a voltage devide with 22k resistors or what...

Yes. See, it's not that complicated. You already figured that 15K+6K8 is just 22K, and you are not using the 6K8 tap.

> I want the EQ section

Cool.... but the input of that EQ is LOW impedance. Worse: varying with frequency and with knob settings. From over 50K to less than 5K. Skipping details: feeding guitar pickup at the R9 C5 junction (even without fuzz-tame cap C4!) will load-down all the highs from the guitar (even the boost will be limited, it loads as fast as it boosts.)

Even when not fuzzing, U1a serves as a useful buffer to drive the tone controls.

Q1 is also a buffer but may not have enough beef to drive the tone control.

For a clean EQ with a little boost and fade-to-zero:

Remove diodes

R6 = zero

R7= 50K Audio pot (12K fixed for unity gain)

R8 = 470

C4= 2nFd

omit the whole R15-Q2 part, connect C9 to R18 to jack

Foo on that Vref1 tap, Q1 can eat Vref2 perfectly well.

Now everything is buffered. R7 about "6" gives unity gain. Full-up gives a boost that might be useful, full-down is dead, and good spread around unity-gain to compensate gain/loss in other parts of your patch. At max-gain C3 holds frequency response to 22KHz so you don't get supersonic troubles.

WTH is a 4557D? A one-off 4558? TL072 would be a fine amp here.

Just going to take this moment to say I love you dude. I'll make a vero for the above. We don't have enough good EQ pedals that are simple.

[Ark Angel HFB]

I'm making up the vero... what did you mean by 2nFd?

[pinkjimiphoton]

2 nano farad

[Ark Angel HFB]

2 nano farad

sigh... it never stop getting to me how 1 extra letter just throws my whole mind into WTF mode...

That "d" had me going... WTF is 2nFd.