Seeking more 3d imaging, deeper/wider soundstage

Realremo,

Check input impedance of your current amp before going with a tube pre-amp. IF not 30k-50Kohm or higher, it might not be the best match. Not all SS amps handle higher output impedance of tube pre-amps equally well. 50-60K amp input impedance is a pretty safe bet in most cases.

If amp is not a good match, you might end up with tube amp and pre-amp sooner rather than later in any case.

Some tube amps have auto-basing. Some are very easily adjustable. Some like ARC require a great deal of skill and lots of patience. Read up on them. Does not necessarily cost any $$. In some cases you might need a multimeter which can be had for as little as $6.00 on ebay. Some amps hold bias better than others. For the most part it's not that difficult. Easier than maintaining set up on a Linn LP 12 ;-).

"Even a cheap system should image and play depth. More has to do with setup (not just placement of the speakers in the room) than anything else"

When I read this nonsense you don't understand audio.

Just sitting here shaking my head at what is probably the most laughable single line comment ever on A'gon.

I don't know what a person talks about depth. I visit people all the time. And believe me most do not have a lot of depth at all. Speakers placed from the wall will not give them a lot more depth. It has to do with the properties of the stuff they own.

It has to do with the properties of the stuff they own.

Bo, you continue to enlighten us with such profound
contributions.

Realremo, a major game changer would be along the lines of Atmasphere's
recommendations ..try to get into tubes. And for me this always has started at
the line stage. Getting into tube amps would be something for later as this
requires more maintenance.

A handful of line stage / preamp products from the past are in the $1k range
and any of these would be a major jump in 3D performance for you:

Counterpoint SA-5 - Absolute killer preamp from the 80s. Way ahead of its
time. The tube regulated power supply has much to do with this unit's
midrange and 3D magic.

CJ Premier 10 or even the remote 14 - Line stages from the 90s. A bit on the
"warm" side but oh such musicality magic as well.

MFA Magus - Another tube line stage from the 80s. Something to keep your
eyes out. I only ever heard the bigger brother Luminescence which was a
phenomenal performer. Wow. So I suspect some of the magic here got trickled
down to the Magus.

CJ Motif MC-7 or other MC models. - These for Conrad Johnson's solid state
preamps from the 80s for those not wanting the "fuss" with tubes. I
owned this for awhile recently as part of a second smaller as was very
impressed with how it outperforms so many new products today which sound
very dimensionally flat in comparison.

BAT VK-3 series - Might be able to find this around $1k. Another great product
from the 90s.

The one product which gets much talk is the Audible Illusions but this was very
dimensionally flat when I compared it back in the 1990s. Just an FYI.

As for XLR connections, do not even worry about this. Your system is at a level
of cost and performance where your focus should be to find budget products
that standout from the crowd. And likely they will not have XLR connections.
And if they do, the likeliness of them being truly balanced designs are slim to
nil.

Once you iron this out, there are many many outstanding tube amps from the
80s and maybe newer in the $1k range that would take your system to the next
level of 3D. But I suggest that you start at the preamp level.