Rotel CDP op amp choice?

[Carlp]

Rotel RCC 955 CDP

This has been a decent player for me, but it has always had a 60Hz trafo hum that, while not loud, is annoying to me. I opened it up to try a few things to quiet it down, and while open I decided to look at the OPAs.

This has two OP275 OPAs. I've read these are dual, so first wonder why there would be 2 (OK, I'm a VERY newbie at digital - valve amp and preamp is more my style). Second, anyone have any suggestions for replacements? Or are they pretty good (I've read some on this site and others about them and they seem to get pretty good reviews, but I'm looking for more ideas on them)? I'm mostly happy with the sound (for digital!!!) but am always looking for an upgrade, especially while I've got 'er cracked open.

Thanks a ton,
Carl

 

[Pars]

On my 855, my favorites when I used opamps were the AD826s. I have tried LM6172s, LM4562, the ADs, etc. in it. THS4031/THS4032 would be on my short list though. Currently using a discreet output stage, and I wouldn't go back 😀

 

[Carlp]

Thanks, Pars. Can you elaborate? What exactly are you using as an output stage? And I assume that means you're using a DAC of some sort too? Or did you modify to bypass just the output?

Thanks again,
Carl

 

[Pars]

I'm using this:

http://www.diyaudio.com/forums/showthread.php?s=&threadid=22542

An no, I don't use a separate DAC but the TDA1541a built into the 855.