I am new to pedals but recently got a Pro Co Rat for free. It is an older model and I think the former bass player had stolen it and our drummer had it sitting in his closet for a long time.
Generally, I haven't ever used pedals but I thought the sound was cool and that there were a couple songs it would work on. The problem--just like everyone says--it cuts out the lows.
After scouring TB I took a couple of ideas I found and put them together. Here is what I did and where I found the info:
1st I went here:
http://www.diyguitaramp.com/rat.html. I took out the 47 ohm resistor and in its place I put 1K trim pot. This allows you to exchange gain in the high register for bass response. The nice thing is when turned all the way it is as if you made no mod at all--it almost sound stock.
2nd I went here:
proco rat mods for bass . I didn't follow all of slinkp's mods as some of them seemed to be outside my skill level. What I did do was take out the .033 cap and replace it with a .022 cap and I took out a 1.6 resistor and replaced with a 10k resistor. Both located just off the filter pot.
The sound is very good. I still need to to some more playing on it but the bass response is definitely there. I found all the parts at radio shack and they didn't cost me more than $4.00 with tax.
Hope this helps someone. Have a great time.
