A look into the AMZ Overdrive Pro

[Jhouse]

Way back when I first started building effects (which was this summer because I'm a novice), I accidentally ordered the circuit board for the AMZ Overdrive Pro instead of the AMZ Mosfet Booster by mistake. At first I was really upset with the effect after hearing sound clips of it and building the stock version. It really, really disappointed me with the overall "fizziness" and lack of output. I read about a couple of substitutions for the pedal to make it sound better and decided to give it ago. I think I have come up with a really good take on the pedal and thought I would share it with you guys.

IC1 - JRC4558D (This chip is the man)
R2 - 330k
R4 - 1.5k
C8 - 470pf
C9 - .0022uf

I like the overall warmness that the pedal brings with these mods. The treble pot range is very shallow (thought it is noticeable when it is on and off), the bass pot acts like more of a presence, and the mid pot is completely worthless (any suggestions on this one are welcome).

Anyways, give it a try if you have the chance. It's a neat little effect if you have enough patience to put some time into it.

[PRR]

> C9 - .0022uf

Are you sure? Not a typo?

The other mods make perfect sense. R2=330K is a small change which affects pickup loading. R4=1K or 2K makes perfect sense: that stock 150 is a LOT of gain, more than some folks can use. Treble cap 150pF to 500pF to taste is a classic tonestack mod.

But C9, tonestack upper bass cap, from 0.47u to 0.0022u, is a BIG change which appears to cut "all" the bass away. That does not seem like it would be "warmness".



0.47u is classic Fender mid-scoop with 10dB-20dB losses and option to be all-bass or all-treble.

0.0022u is heavy bass loss, without an option to get bass if wanted.

0.022u splits the difference; I'm curious if that is your preferred value but your zero key stuttered.

0.22u would be pretty-near stock, just a shade lighter.

(Yes, there is a difference in how the MID pot is connected; it's really "no" different except at one extreme setting.)

[Jhouse]

Once again, Typos are my worst enemy. .022uf was the value of the part that I put in there. 

I actually soldered that in on accident and I was surprised by how much I enjoyed it.

Also, what program is that exactly? I would love to have it.

[Kearns892]

Tone Stack Calculator:

http://www.duncanamps.com/tsc/