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Thoughts on Tube vs SS amplification for Sony SS AR1s

Hi all~
Was hoping someone with more knowledge than me may be able to help clear up some confusion I’ve been having.
I recently was able to acquire my ‘unicorn’ speakers, the SS AR1s.  4 ohms, 88 dB, 28hz-60khz.
i have an integrated tube amp, the  Luxman LX-380, which on paper doesnt seem to deliver a lot of power for these speakers (14 w into 4 ohms), but i have been really surprised by how full/robust everything sounds with the Luxman in place. I had been advised that a more powerful SS amp (‘at least 200 w per channel!’)  would be needed to get the most out of the SS AR1s (and i have had a lot of SS amps in the past), but To be honest I’m pretty impressed with how it sounds already - So,  i was just hoping someone with more experience here could weigh in? Is it necessarily true that tubes just aren’t a good match for a speaker of this sensitivity? Would a more powerful amp like the luxman mQ-88uc (25 w into 4 ohms) be worth looking into? Would a powerful SS amp really make these speaker sing (and i just dont know what I’m missing)? I want to take advantage of the low-end of these new speakers (which is the main difference from my previous pair), so looking for some guidance re tube amps and exerting control over speakers like these.

thanks much!
sfmorris
charles1dad's avatar
charles1dad
10,230 posts
 
atmasphere,
I understand your point and the significant importance of the output transformer. In threads discussing tube amplifiers I consistently advocate the undeniable need for high quality transformers if one is seeking excellent sound quality from tube powered amplifiers. 

My point is if you look at the Sony SS AR1 speaker measurements they are as George and others have rightly noted, a ’challenging ’ speaker load given its impedance curve and phase angle characteristics. Armed with this knowledge the last thing you’d recommend is a 14 watt tube amplifier.

The low watt tube Luxman is doing something obviously good that can’t be surmised from assessing its measurements or those of the Sony. So again, how is this gross mismatch (Via documented measurements for both products) able to produce such high quality sound? Something is occurring that isn’t accounted for with supporting test bench numbers.
Charles
sfmorris OP
14 posts
 
If we weren’t in the middle of a pandemic and people lived nearby, I’d invite you all over for a listen!
ddude003
161 posts
 
I have seen this same phenomena play out with electrostats... Where most Solid State amps that double down/up on watts vs ohms just don’t sound very good while reasonably decent tubed amps, with much lower watts, sound wonderful... Excellent Transformers seem pretty rare in modern SS amps... I suspect there is a correlation between transistors and transformers and speaker impedance most SS amps just don’t play well with... Makes me wonder how bad a Class D amp would sound with these speakers...
charles1dad's avatar
charles1dad
10,230 posts
 

ddude003,

Amplifiers that can double (or nearly double) their power as speaker  impedance is cut in half are touted as mandatory for difficult speaker loads such as this Sony. Although logical to the core, sonic results can be surprisingly poor sounding.. It is  just intriguing that there is no solid  explanation  for a good result such as the Sony speaker/Luxman amplifier or similar such  scenarios.

Charles

atmasphere's avatar
atmasphere
11,575 posts
 
My point is if you look at the Sony SS AR1 speaker measurements they are as George and others have rightly noted, a ’challenging ’ speaker load given its impedance curve and phase angle characteristics. Armed with this knowledge the last thing you’d recommend is a 14 watt tube amplifier.
@charles1dad  In looking at this statement I think you might be conflating high power with the ability to drive difficult loads. But I suspect this load isn't as difficult as it appears, but regardless a small amplifier can easily deal with difficult loads if designed for it. Anyone making a tube amp these days has to deal with the simple fact that 4 ohm speakers and difficult loads are a lot more common than they were even 20 years ago! And I suspect that Luxman didn't go into that product design blind to this fact! 
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