Do Class 'A's do Slam?

Ah. Most preamps stages are AFAICT.

-- Ian

 

[willy] 350 watts per side for the big ones [/willy]

Did I see that you sold the 10As? What did you get instead?

 

My amp is a 100W Class A (although I normally run it in its 20W class A - 120W AB mode). It's 55Kg (transformers and heatsinking) and does get quite warm when running in full Class A mode. Does do slam (if I knew what that was) to my ears though! Titian uses a 200W Class A Krell to drive his subs - and that is huge and hot. I also remember TonyL moaning about the electricity bills when he shared a house with the owner of a Krell 200W class A amp. I think the variable biassing thing is a recent development to produce a more environmentally acceptable solution

(Clearly though, following the previous post, we're only partially endowed)

 

No need for central heating I can tell you

 

My ATC SIA2-150 is 100 Watts class A, then on up to 150 Watts class A/B.

By the time you exceed 100 Watts, it's so loud that crossover distortion is inaudible anyway. As for a wilting PSU, don't make me laugh. The ATC doesn't wilt.

And it does slam and dynamics very nicely thankyou.

It does have chunky heatsinks and weighs in at a fairly massive 19 kg. It takes 3 hours to reach a stable temperature but I think you'd struggle to fry an egg on it even then.

 

If you're looking for valve class A that does slam heavily, you need look no further than the Lumley Metropolis...
Only problem is that it's the size of a small house, and costs the same.

And I once heard an Ongaku On 28w SET produce a surprisingly rockin' sound through Tannoy Westminsters. "Back In Black" didn't quite shake the floor as much as it's doing at this very moment, but then they had neighbours..

 

For a good explanation of why all 'Class A' amps are not created equal, take a look at this from Nelson Pass. Pages 4-8 are most relevant and explain why some 'Class A' designs might run cooler than others.

It also explains why single ended amps are 'a good idea', and why absolute phase is important (a question I raised myself, some time ago).

happy reading

reg