A lot of electronics manufacturers today use a standard design with standard parts to churn out very similar looking and acting products. One of these is the Audio Technica PEQ3 Pre-Amplifier.
Fasterdamnit from the Audio Karma forums cracked it open and discovered that it uses a very common op-amp chip called the NE5532P, he removed the chip and soldered in a socket in its place. After testing out several replacement op-amps he finally settled on the LME49990 which comes pre-soldered into its own custom DIP package which you can see in the image below…
After also replacing the cheap and nasty electrolytic capacitors with high quality versions he has reported ‘a significantly wider soundstage, great detail and imaging, deeper bass and crystal highs’
It looks like a worthy upgrade to an already reliable and solid pre-amplifier, if you would like to read Fasterdamnit’s original article over at the Audio Karma forums then you can go to http://mail.audiokarma.net/forums/showthread.php?t=360210