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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
atmasphere's avatar
atmasphere
12,177 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! 
sfmorris OP
14 posts
 
hi all,
just a quick update but I did a few more casual tests with some other family members (brothers in law, etc) and was as careful as possible not to say anything that would bias them. Everyone so far,  unprompted, has said the same things about the two amps. 
I wanted some other opinions just to make sure I’m not crazy, and everyone has described the luxman’s output as more lifelike and vibrant (referring to the clarity of the mids and highs relative to the sound of the Accuphase) - one brother in law said amp A was like looking directly at the music , amp b was like looking at it through a window. 

@ddude interesting you’ve seen this before too. Maybe it’s a real phenomenon that just isn’t acknowledged much? 
@charles1dad @atmasphere I’ll let you know if I have a chance to test with any other kinds of amps. 
charles1dad's avatar
charles1dad
10,250 posts
 

Atmasphere,

 In a follow up post I specifically mentioned amplifiers capable of doubling their power as the speaker impedance is halved. This would demonstrate high current output/delivery from the amplifier. This is what some have said the Sony speaker requires to drive it properly. There's no evidence to suggest that the Luxman has this high current ability as defined by this criteria..


 Nonetheless it is working in apparent marvelous fashion according to sfmorris. I have no reason to doubt his listening impressions nor those of his guests.

Charles

ddude003
161 posts
 
sfmorris,

I suspect the orthodox SS amp manufactures think the way to manage or handle "difficult loads" are to double the watts to drive the speakers into submission, when not all speakers have the same impedance curves, much to the chagrin of those manufactures... In my own experience, tubed amps and ss amps with autoformers seem to do better at managing those "difficult loads"... To be more clear, not all speakers present the same impedance loads/curves to amps as some manufactures would like or expect...  What happens when you double the watts at the wrong end of the curve?
atmasphere's avatar
atmasphere
12,177 posts
 
 In a follow up post I specifically mentioned amplifiers capable of doubling their power as the speaker impedance is halved. This would demonstrate high current output/delivery from the amplifier. This is what some have said the Sony speaker requires to drive it properly. There's no evidence to suggest that the Luxman has this high current ability as defined by this criteria..
@charles1dad  What you are talking about is the amplifier behaving as a voltage source. Usually that means 'doubling power as impedance is halved' but it does not have to work that way; an amplifier can be a voltage source if it cuts power in half as impedance is doubled. The former is often how solid state amps behave if they have enough power supply current and the output section has the current handling capacity; the latter is how tube amps and smaller solid state amps do it (or somewhere in between, where there might be slightly more power into a lower impedance but definately half the power if the impedance is doubled).  So the Luxman wouldn't need all that 'high current' to be perfectly able to do the job.

The 'high current' thing tends to be overblown in audio to the point of being mythological- current can't exist without voltage and the two together make power, defined by the relationship of 1 watt = 1 volt/1 amp.
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