The 650 is my primary as well. One of the more tonally balanced phones. If the output impedance is set higher than 32 ohms, it can sound a little mushy in the bass and midbass in my rig. How new/old are your 650s? What DAC are you using? What are the tracks the sound too slow or blurred? What SS amp have you compared to the Sunrise?
Sounds like you have a good start on the 9pin range. You may enjoy a Tungsram ECC80 as well. Or the TS 3 Mica 66CG7. Both offer exceptional clarity and detail.
A good change up from the Sylvania GTB is a Hytron 6SN7. It offers more detail and clarity with more high end extension and great 'speed'. Another fast tube is the Raytheon VT-231. It offers exception inner detail, but usually costs more than the CBS/Hytron. The Hytrons are still decent values. The Canadian GE 6SN7WGT is another great value with excellent clarity and speed. As is the Canadian Westinghouse 6SN7GT - if you can find one.
My 650 is one of the newer ones, 2 years old. So far I've been using a Modi Multibit, and the other amp I've been comparing the Sunrise with is the Polaris. The Sunrise is really starting to grow on me, I guess it takes a while to become accustomed to the sound of tubes. I'm still not sure which amp I prefer.
By the way, what does the TS stand for in TS 3 Mica 66CG7?
Frans tuned the Polaris using a rare and exotic JFET voltage gain stage to mimic the sound of a good tube. Although it doesn't permit JFET swapping... yet. ;-)
Polaris uses the same 'vintage' solid stage output stage as the Ember and Solstice. Do you have to choose only one between both amps?
TS = Tung-Sol. Tung-Sol 3 mica 6CG7.
TS RP = Tung-Sol Round Plate used to differentiate the TS flat plates 6SN7 from the TS RPs. The TS RP is one of my fav 6SN7/12SN7 tubes - vivid, dynamic presentation. Goes great with the Mimby in my rig.