Lots of talk of swapping chips in Tube screamer type pedals .. I have a couple of 80's Digitech delay pedals (PDS1002,PDS8000) and noted they use TL062 chips. 2 to drive the input/output volume section of the circuit the 3rd I'm not certain about. Would I get a grittier/warmer sound if I used,say, JRC4558s or 59s ? I know they won't be analog in sound, but I'd like a fatter sound with more inherent dirt. Any thoughts ?