New Cambridge 540 vs. Used Music Hall CD25

I've owned two Cambridge CD players, though not the 540C, and a Cambridge 540A integrated amp. I own one of the original Music Hall CD25's now and have upgraded the opamps myself.

The Cambridge stuff is very good for the money but I would definitely go for the Music Hall if you can find one in good shape. The build and sonic quality are up a level from the Cambridge gear.

Upgrading the opamps in the CD25 isn't any more difficult than changing a fuse and the difference in the sound is quite startling. I prefer mine to the much more expensive separate transport and DAC I had before.

Chaknap

I bought the opamps for my CD25 from Sound Odyssey, who were a regular advertiser here on Audiogon but I don't find any of their ads at the moment. I put in AD8066 opamps, which came from Sound Odyssey mounted on very small adapter boards.

I think Parts Connexion also sells opamps, they advertise mods for the CD-25 and sell parts for DIY projects. You could probably email or call them about options. Underwood HiFi also does mods and might be able to advise you.

Here's a link to the Parts Connexion site. It's poorly designed and difficult to navigate but there are pictures on there of the CD-25 circuit board with the opamps identified. If you can't find them, let me know and I'll email you a picture I saved from my own installation.
http://www.partsconnexion.com/catalog/semiconductors.html

All that is required is that you lift the old opamps off the circuit board of the player by prying up the edge with a small flat-blade screwdriver and then lifting straight up. Putting the new opamps in just requires aligning the pins and pushing down. The only critical factor is to make sure the #1 pin on the board is in the same place as on the one you remove.