Hi Ebuzz. I agree with Charles1Dad's recent post. Only you will be able to know if any tube amp will be a significant upgrade to your existing T-100.
I have a Jolida JD-502P amp and I won an auction for a Hafler 9505 Transnova amp that was fully working. In my system I swapped out the Jolida for the solid state Hafler as I've always wanted to listen to this Hafler amp in my system. I kept everything the same. Now I couldn't say exactly which amp in my system was a significant upgrade but what I could tell was that it made the sound very different. With the Hafler 9505 in place the volume controls on my system got even more sensitive. It gets really loud but still clear with the volume on my preamp at the 9 o clock position.
So just be wary you might not get a significant upgrade in sound you just might get different sound that you may or may not prefer.
I have a Jolida JD-502P amp and I won an auction for a Hafler 9505 Transnova amp that was fully working. In my system I swapped out the Jolida for the solid state Hafler as I've always wanted to listen to this Hafler amp in my system. I kept everything the same. Now I couldn't say exactly which amp in my system was a significant upgrade but what I could tell was that it made the sound very different. With the Hafler 9505 in place the volume controls on my system got even more sensitive. It gets really loud but still clear with the volume on my preamp at the 9 o clock position.
So just be wary you might not get a significant upgrade in sound you just might get different sound that you may or may not prefer.