Resistor value of the R28 on a phase 90

[dric]

Hi guys, anyone of you knows the value of the r28 resistor on the mxr phase 90? I wanna mod it with a toggle switch like evh, but, i seem to have lost the resistor all together. thanks guys.

 

[theblueark]

It's 24k.

Removing R28 does not completely mod it to be the script phase 90 though it is a common simple mod.

 

[dric]

thanks dude. i'd just like to ask, exactly what does removing resistors c11 and c12 do?

 

[theblueark]

c11 and c12 are capacitors. Here they act as noise filters.

R28 is a feedback resistor which causes some distortion in the mid frequencies. It was added in the reissues to simulate EVH's tone when going through a cranked marshall. Probably it caused some noise which led to the addition of the noise filters.

If you had a 3pdt toggle switch you could toggle all 3 of them in or out. Sim Lim tower has these easily available and even 4pdt toggle switches.

It still won't make it a script logo phase 90 though.