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Class D with high efficiency speakers

I'm currently running PS Audio BHK Pre / Atma-Sphere S30 Mk3 OTL into Avantgarde Duo Omega horns (107dB/W 16ohms). I've been very happy with the sound of the OTL's the past 12 years and since retiring have been listening to my system throughout the day as well as evening. This is obviously impacting valve life (although Atma-Sphere amps seem very kind on valves) and my electricity bill.

I'm therefore keen to explore whether any of the new Class D amps would be a suitable match in my system.

I've seen a lot of reviews where Class D amps are feeding low efficiency / low impedance speakers and I can see the benefit of their ability to supply current etc.

My question is, does anyone have any experience of running a new Class D GaNFET amp into high efficiency / high impedance speakers?

rocketiii
rocketiii OP
46 posts
 

Thank you for th replies so far.

I've had the DUO's since 2007 and agree they need thorough set up and matching equipment. I found Jim Smith's book invaluable in getting my listening position and speaker position just right.

The AtmaSphere OTL's are a very good match (I've tried a number of amps) and I really like the sound I've been getting for the past 10 years+. But I've been intrigued by Ralph Karsten's views on Class D and the fact that he prefers his Class D amps to his own OTL's!

Ralph will know more about amplifiers and systems than I'll ever know so it was him that has set me off on this exploration!

I've also been in contact with another Avantgarde DUO owner who is using a NAD Class D amplifier very satisfactorily. 

I like trying things that are a bit different and I'll update this thread as I experiment.

Ag insider logo xs@2x
o_holter
975 posts
 

I would not sell the OTL - wait until you’ve tried other types of amps, and give it time. I have Atma-sphere MA-1 v 3.2 monoblocs, mainly fed by the Io Eclipse. They are a daily joy in our system, with top level NOS driver and output tubes and clean power. I am on regular visits to my friends in our local audio circle, some of them with class D amps, but I always come back thinking that I love the tube OTL sound at home.

I was surprised that Ralph / Atma-sphere - post above - wrote that he didn’t miss it (M-60). I am sure his new class D sounds good. But I would guess it is a case of plus and minus?

russ69's avatar
russ69
3,501 posts
 

I would certainly try it. It might make for a good match. 

atmasphere's avatar
atmasphere
11,793 posts
 

I am sure his new class D sounds good. But I would guess it is a case of plus and minus?

@o_holter Its been a year and a half now and I've not heard any tradeoffs. But if your speakers are designed for amps with a high output impedance (and mine are, FWIW...) things might be different. If you are dealing with a speaker like that you might find the class D to be a bit leaner in the bass because it will make less energy into the impedance peaks that are in the bass region of the speaker.

manogolf
68 posts
 

Give the PS Audio M1200's a trial. Class D using a long lasting tube for the input stage. 

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