Bil Noe wrote:

I have an Adcom GFA-555 power amp and a GTP-400 tuner/preamp ...

The tuner/preamp has gotten fussy lately (flaky right-channel dropouts)
...
Accordingly, now seems like a good time for an upgrade.

...I'm willing to consider a preamp costing up to, say, $1500 *if*
spending that sort of money willbuy me considerably improved sound
(i.e., transparency).

Consider replacing the Adcom amp with a second-hand Bryston 3BST for
under $750 or a McCormack DNA-1 for under $800. The Bryston has a lower
noise spec (it is very, very quiet) while the McCormack might be a bit
more musical. Both are considerable upgrades over the Adcom. If you
want to buy new, the Bryston 3BSST is available for around $1700 if you
shop carefully -- it's quite a fine amp. Or perhaps consider the
McCormack DNA-125.

You might consider doing without a pre-amp altogether. If your sources
can drive the amplifier directly, all a pre-amp offers is more noise and
switching options. Instead consider getting a passive pre-amp/switcher
like the old Adcom SLC-505 for around $100 or less.

Add an external phono pre-amp if you need it. The older Rotel RQ-9708X
was a good sounding unit and is available second-hand at low cost.

--
Len Moskowitz PDAudio, Binaural Mics, Cables, DPA, M-Audio
Core Sound http://www.stealthmicrophones.com
Teaneck, New Jersey USA http://www.core-sound.com
Tel: 201-801-0812, FAX: 201-801-0912