To my ears, music is a bit more alive. Can't comment beyond that because after I did all the internal electrical circuit mods, I pursued a different track - external electrical circuit mods. I was still not contented with the sound and I thought the other proposed mods - vibration dampers, 75ohm termination at dig out etc are a complete waste of my time
They only look good in the forum or on paper. Straining my ear at 2am in the morning is not exactly what I call improvement. If there is improvement, I should hear during normal hours on a relatively quiet day. And verifiable by a comment from a female or double blind test.
You need the OPA2107AP which comes in the PDIP-8 (plastic dual in line) package. The OPA2107AU comes in SOIC-8 (small outline integrated circuit - this is surface mount) - not normally what is placed in a CDP or DVD.
Specs wise, max input voltage is +/-18V which is beyond what is typically supplied to this IC which is +/-12V. The offset voltage and bias currents are quite low. The slew rate is quite high at 18V/uS. The 5532 I believe is < 5V/uS.
Pros - good technical specifications, Cons - a bit expensive (may hover around the Php 600 - 800 per pc - could be higher, not 100% sure of this though).