Tube amps under $7500

I would stay away from 75 watt tube amp then. I’m using a Reference 3a reflector and Joseph Audio Pulsar. The 3a’s play just fine, sometimes I would like a little more power with the JA. Both are very enjoyable with 50 watts. If you need power and current and want tubes may want a preamp and mono blocks. Tubes can get expensive and heat in summer months can be an issue. Needing big tube power makes it tricky.

My personal favorite is Sophia Electric...a number of excellent sounding amplifiers and what you hope for when you go to tube amplification.....

So many more fine tube amps out there than I ever dreamed existed. But in order to get their benefit, I would need to change speakers and add subwoofers (which don't augment, but actually constrain, the performance of Legacys in any configuration possible for my space). These are -6dB at 22Hz. Many superb speakers hit -6dB at 30Hz or above. It took the contributions on this thread to make me recall why I had gone with Legacys in the first place. Fully enclosed, can be placed near front wall. High frequency hearing loss and compensatory bias toward low bass articulation. It's a long list.

re: "For pairing experimentally with various tube and SS preamps."

Some members may be running right past this requirement in your original post.

If I were in your shoes [IF  this is truly a requirement] I’d probably be looking at manufactures also offering a nice matching (primary) preamplifier that you’ll enjoy along with your selected amplifier(s). Matching up the right preamp matters too, many will chime in here or just look at old threads on this topic.  Next is your balanced connection requirement, which limits the field as others have already stated. With your stated $7500 budget limit set for the amp(s), does this change overall spend equation some if the budget for the [balanced] preamplifier is also brought into discussion now too?

Mixing and Matching:

Like others here, I too pair up my SS and tube preamps with SS and tube amps. Even with good-full Class A 50w SS, in the end solid state sounds like solid state, and tube sounds like tube. Sure, mixing types of each produces a nice hybrid sound. @hickamore gotta ask, can you see yourself also drilling in a little more on your choice of preamplifiers now too?

While looking at amplifiers, maybe take some time and focus to look at good preamplifiers, before selecting your primary tube amplifier. In my systems, the preamplifier choice has a notable impact on the result and enjoyment. One thing is for sure in my system, when I connect my best tube preamplifier into the mix, something really nice occurs about the sound. Matching with the amp matters. My .02 cents fwiw.

Ask:

Do you also have a sense as to what manufacturer’s PREAMPLIFER and model you might choose as your primary preamp for your system?