B & W Matrix 801 S3 and tube amplifier

Even in a small room for "mostly" low level listening you should have as much solid state power as you can afford for that speaker.

I recommend Mark Levinson for the 801 series 3. You should be able to pick up a 23 or 23.5 in your price range. If you go with Levinson you will want to sell your CJ preamp and look for a Levinson preamp.

"“This amp is a copy of the Williamson circuit from 1947 without the driver stage. Not very quick and average bass performance."

This is just the opposite of what the 801's 12" woofer needs to sound its best.

801s deserve better.

Pvctor, The Levinson amplifiers I recommended are outstanding with 801 Series 3 speakers. The only thing better is Levinson Class A monos, but you will not find them within your budget. The only Parasound to consider is the JC models (John Curl) who also designed some of the early Levinson products which are still in high demand. All of the new equipment that compares to the amplifiers I recommended will cost a fortune and everything else is a shot in the dark. You will most likely have to lose the CJ preamp and find a Levinson preamp. You don't hear much about them, but they are extremely good preamps and will give you the most from the Levinson amplifier. You will not be disappointed with that combination.

There are a lot of good amps. The trick is finding the right match.