First class - F5 / F5 turbo or F6 for tannoy 15 speakers

So nearly happy with whole setup - rega r8 or linn klimax DS into tron seven pre /then atc P1 into tannoy ardens

Problem with volume is I can hardly use more than first 1/4 so want something that works from late night listening levels up to about 90db at max for nearly all my listening. Only read good things about first watt but trying to decide between F5/F5 turbo and F6

Would love opinions if you know these amps