Amplifier brand/designer with the most unique and consistent “house sound?”

@condosound, @chorus
Never heard Lejonklou or LTA amplifiers?  What is their sound signature?

I gotta hear these dang Ayer amps, huh?

How would the house sound of Ayre best be described? 

@atmasphere writes 

You also **at the same time** must have the same distortion percentage at 100Hz, 1000Hz and 10,000Hz. Many solid state amps have excellent distortion figures at 100Hz, which is why they are usually measured at that frequency. But if you measure at higher frequencies, like 10KHz, you find that the distortion is higher.

If you get rid of distortion and phase shift across all frequencies, will all amps sound the same?  Should they?  Even with different topologies, parts?  No more house sounds?

What amps have taken this to the mathematical extreme?

@atmasphere - thank you for such a rich explanation of harmonics, feedback, distortion. In other words, a house sound is a house distortion profile.

That being said, are there other factors aside from harmonic and intermodular distortion that might account for different house sounds? Are there other factors which make different amps sound different, even with negligible distortion of any kind?

For instance, some amps are better with rhythm, tone, attacks, decays, timbre than others. These can be part of the house sound, maybe at expense of other qualities, maybe not. 

@atmasphere

Different resistors, capacitors, wires endow amplifiers with unique and often predictable coloration/qualities.  Do these components vary in their distortion/phase attributes in predictable/measurable ways?  Or are other characteristics of these parts contributing?

@atmasphere fascinating and clarifying. Thank you.