Tube Phono Stage with balls, and slam!!

Another vote for Herron here. Especially if your cartridge sounds better with non-standard loading. My Soundsmith Paua likes 2k ohms which is difficult to find in phono preamps. Keith Herron can supply just about any loading resistor you would ever need. It is also great for tube rolling. Keith is also very responsive and an interesting guy to talk audio with.

+1 for the Vincent pair,
it has the tube input for your "tube" sound, but from what I can see on the net, a solid state output to be able to give you drive and dynamics. It is very versatile, with different gain options and it looks well made.
http://www.vincent-tac.de/en/product-types/phono-preamplifier/pho-700/

Another good one is the Schiit, no tube though, but very cheap.
http://schiit.com/products/mani

Cheers George

Fremer described the sound of the Liberty B2B-1 phono amp as being what you may be looking for. It has an extremely high overload figure, a very good thing.

As someone else mentioned, getting enough voltage gain overall in your system is paramount in obtaining optimal sonics, and I personally like tubed phono stages like my Manley Steelhead phono stage

Just for the record, the Steelhead is a hybrid phono section, employing a solid state input.

davyonthecoast ...

Has anything been done from the standpoint of room treatment? If so, what?  If you've done nothing, then some of the "brightness" at loud volumes could be certain frequencies exciting (causing resonances) in various areas of your room (even the ceiling)  and therefore smearing your sound at those frequencies and being interpreted as "brightness."

Try a ten-pack of these HFT's and install as directed. This is NOT a subtle tweak: 

http://highend-electronics.com/products/sr-hft-high-frequency-transformer

I have owned the original Well Tempered TT since it was new. Its exactly like the one you are using. When set up properly, and using certain tweaks, it is one of the finest sounding turntables out there under $50,000. No joke. 

Have you done anything to dampen the tonearm well on your Well Tempered turntable?

Here's some images of the brass Margio Well Tempered tonearm well dampener. The Margio clamp really gets the resonances caused by that thin-walled well under control. Without the clamp, the micro vibrations of the thin walls of the well are smearing your sound and contributing to that "brightness" you're hearing.

I don't know if the Margio clamp is still available, but you could research that. This is a major improvement for the Well Tempered turntable and the improvement is heard immediately. Night and day, really. 

http://search.aol.com/aol/image?q=well+tempered+turntable+Marigo+Well-Damped+Arm+Clamp&v_t=webma...

A huge improvement can be had by replacing your turntable belt with a custom belt from www.oringinlive.com  This is NOT a subtle tweak at all. Its major.  Its like upgrading a piece of electronics, like a better amp, or preamp. You say you like "slam" and "dynamics?" Well installing this belt is the way to get it. 

Also, consider getting your tonearm rewired with Cardas copper wire and use the Cardas junction box for your turntable's RCA inputs.  This is another tweak that will get that brightness under control ... and improve everything else in the process. 

One layer of shrink wrap on the tonearm is another good tweak for the Well Tempered arm. 

Another area to consider before spending huge amounts on a new phono stage, cartridge or other expensive equipment is to pay attention to, and eliminate as much as possible, micro vibrations throughout your entire system.

For example, what is your equipment sitting on? Glass shelves, for example, are a death knell. Are your speakers spiked to the floor? Have you tightened every screw on your speaker cones? Are you using cable elevators of some type for your speaker cables?  These are just a few examples, but there are tons more.

 Keep in mind that everything vibrates ... and the only thing we want vibrating is that thin wire with the diamond on the end that glides through the record grooves. 

I've seen some very expensive systems where the owner has paid no attention to micro vibrations at all ... and the system sounds like crappola. On the other hand, I've seen some moderately priced systems where the owner has paid attention to all of these fine details and the sound knocks your socks off. 

Before throwing tons of money at your system, take care of the small things first. In this crazy audio hobby, the devil is in the details. 

Hope this helps. 

OP