OK I give up, searched BR, searched BR wilki, google and can't find out what exactly 'Reference class audio amps' are.
Loads of adverts for them but no details.
How do they differ from the ordinary type of amps we use? (Class A/B, C, D etc)
I get the impression that they are bog standard PA amps with a coating of snake oil but I'm usually wrong!!

Yep, when related to amps, it's normally a tag that insinuates quality - certainly to people who know just enough to be impressed. People have been using reference speakers for years, not to signify overall quality, but design that produces a 'sound' that helps the engineer assess the sound source in some kind of context. A pair of reference speakers in a studio make a pretty good starting point for a well balanced mix that travels. I suspect people hearing the term have transferred it to amps - which are very different, aren't they - in so much as they are supposed to just amplify, not modify, the sound supplied to them. Behringer make a reference amp, but I suspect it's an advertising ploy. I also found some hi-fi reference amps at 3 grand that are 40W per channel - Ha Ha!

Thanks Paul,
To me they should be ultra linear from DC to 30khz, miminal noise floor etc, in fact the perfect amplifier.
Thanks again for clearing that up

'Reference' quality in the hifi world means completely different to the pro-world.

If a company labelled their amps as 'reference' quality in the pro world, it's simply a marketing ploy. They might as well write 'very good sounding', and not look like idiots.

In the hifi world, the term 'reference' is used to refer to amps/kit which shows a completely neutral response + low distortion figures + high dynamic range (ie, very low colouration). A good example of reference amps in the hifi world would be Classé, whilst a good example of non-reference amps in the hifi world would be Naim.

Either way, the term is often just thrown around like there's no tomorrow. It mostly just gives people who actually know their stuff a chance to laugh...

Yep

Reference quality should be an unadjusted sound that inticates what you want to hear without other factors

you could say that if your recorded mix is aimed to be played on a 80's boombox

then you should do the mix listening to the sound through one, then you could then say
that it was your reference
but that is subjective

its like any use of the word, its the original way it was created and what to relate back to if needed

Reference quality stuff (as stated) should be able to offer a full bandwidth sound with no bias toward anything
so you get a true result

I wouldn't use the term as a mark of quality for PA kit, maybe studio work

Cliveybaby