I use a Cayin A88T with my Spendor S8e's and to me they sound wonderful. Plenty of power with 45 tube watts. Be aware, you will probably need close to that many watts with the Spendor 3/5 with a tube amp because for the same amount of input, when I compared the two (I owned both at the time), the Spendor S8e's sounded louder.
Tube amp for Spendor S3/5 SE
Recently acquired a pair of Spendor S3/5 SE from a Audiogon member. I am an audio enthusiast and mostly listens to Vocals at low to moderate volume. I never tried Tubes and really want to try them. Could you guys recommend me a tube amp in ~$1000 range. Because of easy biasing, i thought of trying Primaluna Prologue One, but i am afraid it will be underpowered for Spendors.