+1 @decooney
Your speakers needs a good SS amplifier. Some may not agree, but when your impedance drops below 4 ohms, it is a problem for tube amps to drive it. Even though specified sensitivity is 90dB, looks like actual sensitivity is close to 87dB. Your speakers have sensitivity and impedance characteristics similar to Thiel speakers except for the phase angle.
You should try Audio Research 100.2 amp. There are several used ones available in ebay, Audiogon, TRM, etc. This amp will give tube flavor you are looking for, except this is a SS amp. Very musical and highly recommended. And there are many other options as well.