Comments on: Quick Rat pedal mod

By: wackie

wackie — Sun, 29 May 2011 17:09:17 +0000

I’m trying to ‘tighten up’ the pick attack ‘low end’ of my turbo rat with no luck. i’ve reduced the r/c in the feedback loop to one set and tried a 100 ohm / .22 uf polyfilm corner fre. of 7,238hz but the lowed now crackles. should i put the r/c back to original and try messing with cap/resistor values before the op amp? or should i try a .22uf metal film cap instead?

By: wackie

wackie — Thu, 26 May 2011 14:03:15 +0000

correct me if i’m wrong here. but if the resistor comes first and the cap comes second, doesn’t that make it a low pass filter and not a high pass filter?…….really new at this and trying to learn. thanx.

By: GGBB

GGBB — Mon, 18 Apr 2011 14:43:38 +0000

I am curious about LC and jim’s questions also. I would think that it’s not quite as simple as the parallel/series values of the components, but I don’t really know. I think that the two resistor’s first act as a voltage divider, and the capacitor’s then determine what frequencies are filtered out according to the output levels of the voltage divider. And since there is a different cutoff frequency for each path to ground, the slope of the filter is greater where both paths to ground apply (below 60.5Hz). So there would be two knees on the frequency response curve as opposed to just one.

By: jim

jim — Fri, 18 Mar 2011 17:57:58 +0000

Instead of seeing two seperate high pass filters could you not look at the filter frequency as the parallel of the two resistors, 43 ohms combined with the total of the capacitance, 6.9 micro farads, giving a corner freq of 536 Hz?

By: LC

LC — Sat, 18 Dec 2010 22:46:12 +0000

I wonder what “sucked” means specifically. Anyway, what was the purpose of having two high pass filters on that part of the original circuit?

By: jbmannon

jbmannon — Tue, 23 Nov 2010 00:47:08 +0000

I tried the ruetz mod it sucked tried with the c6 .47uf capacitor and it sucked.The only way it sounded decent is when it was maxed controls out out.
Settled for a switch with led clipping one side and stock clipping the other side.
If you want the ruetz mod just turn the gain down and the volume up it sounds better than the mod an does not lower thge value of the pedal. IMO leave it alone and adjust your pedal and amp to compensate.The clipping mod is the only one i would suggest.

By: samsara

samsara — Fri, 21 Aug 2009 16:05:47 +0000

I want to add more bass to my Vintage Rat (witouth the losing-gain deal). Also have a Dirty Rat but I can’t use it because its noisy as hell. Even with the guitar volume rolled off. Could you help me, please?

By: Pekka

Pekka — Sat, 17 Jan 2009 11:00:39 +0000

I did something similar couple of years ago. I also got the idea from the Ruetz rat. More here: http://kotipolttoinen.com/wanha/sisalto/kitara/rat_mod/index.php

By: Erik

Erik — Wed, 07 Jan 2009 05:55:06 +0000

This is a great mod. After reading over it a couple times, I decided to crack open my Rat II and do the deed. I just clipped the side of the 47 ohm resistor facing the op-amp but I will most likely desolder the rest of it and remove the 2.2uf cap as well. I didn’t mess with C6 yet but I’ll know if I’ll need to after a couple gigs this coming weekend. Thanks again, Jack. Your site is one I frequent when it comes to things DIY.

By: wgtp

wgtp — Wed, 01 Oct 2008 16:35:36 +0000

I prefer to disconnect the low frequency leg, or add the 4.7uf cap to the 2.2uf cap for a mega rat.