I do love the Rat pedal. I don't actually own an "official" one, but rather a clone made from a ready-to-solder circuit board from General Guitar Gadgets. I tend to switch it on and off my board every so often, and from time to time I dream of making my Rat clone even more awesome. Recently, in that spirit, I was looking at Jack Orman's wonderfully informative page about his moded version of the Rat called the Fat Gnat. He mentions that there are some alternatives available for IC selection. This makes sense because althought the LM308 is the orginal chip and "holy grail" that most people use when builidng their own DIY Rat, I have heard that some versions of the Rat use the TL071 or other chips. Jack recomended trying the TL071 as well as his favorite the NE5534, in addition to the LM308. So I did, and I recorded the results. As in the other IC tests, I recorded a clip into my Boss looper, and then ran that same loop into my Rat clone 3 times, each time through a different chip.
Check them out. Which one do you like?
Testing Different IC's in a Rat by afrogoose