Vintage Amps for Thiel 1.5


I have a pair of Thiel CS 1.5s that I love for their clarity, imaging, and tonal balance, but sometimes I wish they were a bit more dynamic in the mid bass.

I have been driving them with an old Sony TA-1150 (35w rms, 150w dynamic into 4 ohms), that sounds great but I worry may not have enough power. I usually keep the volume control at around 1/3 - 1/2 and rarely feel the need to go above 1/2, so is my amp powerful enough after all? Is the lack of kick drum punch just the limitation of the Thiels' 6.5" woofer?

Or would I get better punch with a higher watt amp from the '90s? What would you recommend for around $500? 

Bryston 3b? Creek 5350SE? Carver?
aalden
I haven't the slightest idea about your Sony amp.  But the Thiel CS 1.5s were the main reason I got re-interested in high-end audio back in the mid 90s.  They were being powered by a Pass Aleph 3 amp and I think a Bryston pre, and it sounded incredible -- very balanced and refined with excellent imaging and soundstaging.  The 1.5s seemed to thrive on that Class A power and oomph, and if I owned those speakers I'd be scouring the net for that amp and maybe even an older Bryston pre.  Personally I think those speakers deserve better than a $500 amp, but best of luck in your search. 
If you can find a working Bryston 3B for $500 - buy it! I have one (and that's what I paid for mine from the original owner).      An excellent choice for ANY Thiels!
Think about adding a sub because that small woofer just can't move enough air!
BAT or Classe.  Match these with some MIT cables and a tube preamp and enjoy.