Lush and Romantic Tube Amps

Can anyone provide a working definition of "neutral?"  In other words, a point from which we can agree is indeed sonically neutral?

Neutral equipment makes no editorial of the signal. The Absolute Sound magazine gets its name from the idea that the musical source is the absolute sound; neutral would be exact reproduction of that without coloration of either warmth or brightness- just the music.

Establishing a reference quickly becomes an item of concern. The only way I know to deal with this is to make high quality recordings of musical events at which you were there, so you know how its supposed to sound.

To atmasphere:    Knowing your background of tube design, etc., would you recommend perhaps using a SS power amp with a tube preamplifier?  Or perhaps a ss / tube hybrid integrated?  Thanks.

@gregjacob If the speakers are low efficiency as the speakers of the OP, perhaps yes if the amplifier used isn't harsh.

'Warm and lush' is a sign of a prodigious 2nd harmonic. Our ears interpret the 2nd and 3rd as 'warmth' and these harmonics can mask the presence of higher ordered harmonics (5th and above) which the ear interprets as brightness and harshness (typical solid state attributes).

There are class D amps that don't make the higher ordered harmonics like traditional solid state amps do, and so sound very much like a very good tube amplifier. Driven by a tube preamp, such class D amps can be extremely life-like and satisfying.

I am on a quest for a lush, warm and romantic tube amp. Ideally, it should be 75 watts and upwards. I’m in a large room and my speakers are 87.5 sensitivity and 8 ohm.

@bluethinker If the above is correct you will find that 75 Watts is not enough power. A large room, combined with the low efficiency of your speakers will not allow the amp to play all forms of music without overloading. IME you'll need at least 300 Watts with speakers of that efficiency!

So if you want to use tubes (tube power has always been expensive BTW...) you'll want a speaker that is a good 6dB more efficient. That would put you at about 93dB. 75 Watts would then be able to drive the speakers as loud as the 300 Watts on your current speakers.

The cost of tube amplifiers is why there were so many high efficiency speakers back in the old days (1950s and prior). There is no reason why a more efficient speaker should trade off resolution with a less efficient speaker.