Tube amp for Avalon Eidolon ?

I have no experience with tubes, and want to give them a try on my Avalon Eidolon (not diamonds) speakers (87 dB sensitivity, 4 ohm nominal, 3.6 ohm minimum). I'm using dCS Elgar + Purcel front end and currently not using a pre-amp, cardas neutral reference cables. I listen mostly to jazz, some classical, some rock.

Looking for suggestions on tube amp(s), preferably with balanced inputs, but not mandatory. I'm willing to spend some money, up to say $15k, and will probably try to buy used.

Thoughts and recommendations appreciated. Thanks. John.