chunky_john wrote:

(Tried posting this on rec.audio.high-end. Got lots of advice, but
no-one actually answered my question...)

Current system: Marantz CD63 KI Signature, Arcam 8/8P biamped to
Monitor Audio Gold Reference 20s via Chord Odyssey 4. Interconnects
are Cambridge Audio Studio Reference.

Have just upgraded speakers & cables. Very nice!. What next?

My thoughts are interconnects first, probably CD player second, then
amplification last.

Nice way to do it exactly the opposite of what will increase your
sound quality the most, but it's your money.

Interconnects: Chord Anthem has been suggested - presumably this ought
to be pretty upgrade-proof, but pricey.

Interconnects and speaker wires are useless for a setup like this.
They look nice, but are sonically indistinguishable from plain
electrical wire. Save your money - you've already gone WAY overkill
here.

CD/amp: I am very tempted to try a Cyrus system, eg Cyrus 8, CD 8 &
SmartPower (Having 'gone bi-amp', I would never go back!).

CDs are digital decoders. Any unit made in the last few years will
do exactly the same job. Either it sees a 0 or a 1 and the D/A
converter chip reassembles the sound accordingly. Again, you've
gone way overkill here as well.

A modest windfall and an understanding wife mean budget is circa
£3-4000.

So we come to the REAL options - amplifier and speakers.

Amplifier - what you have is decent enough to run most any pair of
speakers. That leaves...

Speakers. This is where 100% of your budget should go. Get the
best speakers that you can, as the Reference 20s are not even
in the same league as what 4000 pounds could purchase. Even consider
big planar or electrostatics.