need an amp...

Tube or SS?

McCormack.

The Accuphase P300 is an amplifier I thought? For those Vandersteen 2CEs I would say get a used McCormack DNA-1 or DNA-1 Deluxe. Sometimes they can be found here for about $800 or more but they will go fast at that price.

Be careful to avoid an amp that DOESN'T work with classic rock from the LATE 70's...or only works with blues...I had an amp that worked with blues but when a passing chord, modulation, or more complex song structure occured it was LIGHTS OUT. I hate that. An amp that plays music from 1975 but balks at 1978 can be limiting but clearly period appropriate. As long as you use an amp for "some jazz" and don't put too much jazz through it it can work fine, but be warned...I played a bunch of jazz one day through my classical music amp and my cat caught fire. Sad...but hey, you can't be too careful. You really need several amps for different musical genres, and trying to dodge that fact can only lead to trouble. Play Dubstep on a Mumblecore amp? No way man...

Two things: The Vandersteen 2CE is likely not the best at bass articulation and secondly, your muddy bass problem could be largely due to the acoustic properties of your room or the speaker's placement within your room.