AT our coll we use LM741 for amplifying the signals.Input were from function generator and the out were seen on the screen of CRO.i regret that i didnt played around with audio.
The beresford caiman also uses the LM4562. The hf is very smooth, mids are almost 3 dimensional and forward but it lacks a little weight and heft in the bass although the bass is quite precise.
I want to try the TI OPA2132 in my Caiman. Obviously i will need someone's help..... Any diyer's in Delhi NCR area ?
I think the Caiman uses the 8-pin DIP socket for the OPAMPs (based on gut-pics from theartofsound.net forum) so you can actually plug-and-play. You just need to source the OPAMP (make sure it is a "dual" model).
The folks at theartofsound.net have a lot of detailed threads on Caiman Mods. I've been spending most of my free time going thought them over the last week or so. 99% of it goes above my head -- I'm a total non-techie -- but it is interesting to know what is possible.