How powerful is a Wavac MD-300B

Pani,
The problem is that the power rating doesn't tell you much. There is a
hierarchy that exists in the ranks of 300b amplifiers , based of quality of
construction, power supply and transformers. This is why one will drive a
particular speaker well and another ( same stated power rating will
struggle). The two WAVAC SET 300b amps may have the same power on a
test bench but likely sound "very" different and vary in their drive
capability.

I don't agree with the blanket statements made about these amp's
limitations, you must consider which 300b amp is in question for reasons
already explained. My 8 watt SET drives my 94db/ 14 ohm speakers easily.
Isochronism is right, at some point you simply must get these amps on
your tannoy and find out for yourself.

One other issue with Tannoy speakers and their sucess rate (or failure) with 300b SETs is that some models are easier driven and a more efficient load than others.It`s probably a mistake to assume all the Tannoys will have a similar result with the same amplifier.
Regards,

Pani,
There is a Wavelength Triton Signature(upgraded wire and transformers,power,output and interstage) for sale on this site.This is a very highly regarded version of this 300b SET amp!Built by Gordon Rankin and these don`t come around often.
Regards,

Pani,
Okay, now understand your position.I suggested the Wavelength(especially the Signature models) as I know they and Coicident are very upper echelon 300b SET amplifiers that I`m familiar with(both are rare to find used). There are other very good choices also. Best of luck to you.

Charles,

Good points Al,two 300b SET amps from the same manufacturer with significant differences in price,weight(likely bigger and better transformers) and front end tubes in the circuit.It`d be no way to extrapolate the sound of one amplifier based on hearing the other. Pani you could still really like the WAVAC MD 300b version but you need to hear it on your speakers.
Regards,