Rrog is spot on. The 70 watt tube amp will work and produce nice sound, but the power reserves and headroom will not be there for complex and demanding material at higher volumes. The speakers will not sound as good as they could as they will be dynamically limited in respect to your current amp.
Amp and speaker matching.
I wanted to know if anyone out there has driven a harder load speaker (86db to be exact), with a Tube Amp around 70 watts? I was thinking of driving a pair of Dynaudio Contour 3.0's with a pair of Prima Luna 7 monoblocks 70watts. Currently I use a Solid State amp 350Watts. The Dyns love power so im afraid to drop down in power.