A peek inside the Rotel RCD-991

Overhead view of the inside



Gold plated sockets installed for opamp rolling



OPA627BP opamps (slurrrp) waiting to replace the stock OPA2604 and NE5532 opamps.



Close-up of one of the browndog mounted twin OPA627BPs.



OPA627BPs installed in the analog out put section.



The 2 big Nichicon Great Supply reservoir caps. Notice the Wimas and Blackgates nearby. There are roughly 20+ Blackgates capacitors in this player, all surrounded by the red Wimas.



21 generic nichicon caps located in non-critical areas of the player were replaced with low-impedance Panasonic FCs. You can see some of them in the picture. No other replacement was done as the player is already filled with Wimas, Blackgates, Nichicon's top-of-the-line Muse KZs(in the analog output stage) and a few Finegolds.

The RCD-991 is a fine player, even in stock form, and for the build and parts quality, a real bargain at between 500sgd to 800sgd in the local(Singapore, not sure about other countries) used market. A current model player with similar build quality will cost a lot more than that. Its a great way to get high end performance and build at a fraction of the price. Fantastic for redbook and hdcd playback.

Caps and ic socket installment was done by Dreamslacker(aka Firefox on sgheadphones). Opamps were bought from fellow head-fier and cpfer ufokillerz. Thanks buddy!

20 bit Burr Brown PCM-63P D/A converter plus a HDCD-compatible Pacific Microsonics PMD-100 8x digital filter.

"The RCD-991 includes switchable dither levels, a feature it shares with the Linn Sondek CD12 which happens to use the same digital filter"
the above taken from a hi-fi choice review.

link to review

Thanks!

Taymat, you have a point. Amp matching is quite important, after the mods were done I hooked up the player to a Corda Ha-1 and at first thought something had gone wrong because it was sounding very laid back. Re-connecting the player to my own amp, all was well. Depends on your sonic preference really.

There was a subtle improvement in overall musicality with the 627s, not a drastic change, but definitely audible. I might try AD8066 opamps sometime in the future just to see how it affects the sound of the 991. The OPA627BPs are definitely my favourite opamps, with 4 in my amp and now 6 in the RCD-991, there's now 10 of them in my signal path

the opamp sockets are not stock. but yes, the Blackgates are(thats the very interesting thing about Rotel, they use Blackgates in all their cd players..well, not sure about their current models, but I've looked inside the RCD-971 and RCD-855 and they all have Blackgates in them).

Hmm...lets see:

1. Replace finegolds in the digital power supply with Sanyo Oscons
2. Class A biasing for the OPA627BP opamps
3. Net Audio CLock and Clock PSU (Maybe)
4. New heatsinks for the voltage regulators

P.S. thanks for the info Stryker.