Zyx Universe. O.24 mv vs .48 mv with low eff spkrs

My apologies to all, but esp. to Atma. My last post was poorly worded. The reference to being more concerned w hum and noise was based on two things. One, just an electrical/acoustical fact of life. A higher eff speaker will reproduce the inherent hum and noise in a system at a higher SPL than a lower one. At least I think that's a fact of life. Second, my recent experience w both push pull and and PSET amps (but not w the Atma OTLs). When switching between two speakers of differing efficiencies, I always heard more tube rush or hum or noise from the higher eff speaker. I was not in any way trying to say that Atma amps were noisy when mated w high eff speakers. My bad.

Since I generally can't stand horn speaker distortions, listening with my head deep inside the horn is often the only way I can tolerate them. Swampwalker's advice and Ralph's clarification are spot on!

<:-)

Swampwalker's advice and Ralph's clarification are spot on!

+1, in both cases.

With the slight qualification that the hum and noise which will be reproduced at a higher SPL by a speaker having higher efficiency is hum and noise that is generated or introduced at points in the signal path that are "after"/"downstream of" the volume control.

Best regards,
-- Al

The speakers at the Munich show were Hornfabrik:

http://my-hiend.com/leoyeh2/2014b/IMG_3428ss.jpg

Since the jumpers used in the Atma amplifiers to reduce gain do reduce gain by converting the voltage amplifier stage from a dual-differential cascode to a simpler dual-differential topology, it is entirely possible that the signal to noise ratio might well go UP rather than down with vs without the jumpers. Cascodes have a pretty darn good signal to noise ratio. But in either case, there would likely be no problem except possibly with ridiculously efficient speakers, i.e., >105db. (I chose a number out of thin air.)

On the subject of speaker efficiency: I think the benefits of efficiency, if you define that as 90 or 92db and up, are huge, provided the speaker is otherwise well designed and pleasing to its owner. I do not care for much less efficient speakers, if they come by their inefficiency by virtue of a multi-way complex crossover, regardless of how huge and powerful the driving amplifier may be. I don't find that huge power can overcome the sluggish behavior of such speakers. On the other hand, horns are not my cup of tea, either. They invariably sound great for the first 15 minutes, however. This is purely and only my own opinion.