Dont.
I have no idea how they say a 2 wpc amp will drive 89dB speakers. I’m using 2wpc on my 96dB speakers.
I generally don’t recommend tube amps for insensitive speakers. Many do it but I don’t think they get the advantages of a tube amp like they would with a sensitive speaker and end up with a compromise.
I’d go with a 25 wpc class A solid state amp.
Jerry

