I'll put that one in my 'special book', Tim

Dave,

Marco, can I take up something you said earlier? Comparing a little single ended valve amp with a mega power solid state one will definitely bring out audible differences and these differences will be measurable too.
Indeed. Like Tim said earlier, debates like this are partly due to semantics; in this case the use of the word "monumental".

I guess that truly "monumental" differences in hi-fi only really occur with speakers or when the same equipment is used in a different room.

However, I've certainly heard, let's call it, 'very significant' differences between amplifiers, particularly as you say between low-powered tube amps and high-powered transistor amps when used in the same system with appropriate speakers.

Marco.