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Class "D" amplification with Shahinian Obelisks...

TimF

TimF

pfm Member
Anyone tried or use class "D" amps with your Obelisks? I am curious as to what brands and how well-or not, that they worked with the Obs. Seems most of the ones I have seen may not always cope well with loads under 3-4 ohms, but I admit, no expert on the subject, so appreciate any comments. Thanks! Tim
 
Tim

I demoed an Audio Research DSi 200 integrated into my Obelisks and it was stunning. The DSi 200 uses ARC's "proprietary" implementation of Class D and the results are very impressive. The bass grip and dynamics are what stood out for me. I also found just enough of the traditional ARC "tubelike" sound to find the amp very easy to live with. I subsequently purchased the well regarded Dynavector HX-100 but never compared the two. Can't really compare from aural memory either as I subsequently moved the speakers to a different location.
 
I demo'd the Lyngdorf Power Amplifier with my Shahinian Obelisks, and I'm afraid that it didn't cope at all well, the sound just fell apart when bass (or volume) was required.
 
I doubt that a class D amp would have the necessary requirements. Shahinian's bass loading places substantial demands on the amplifier's current-delivery and damping-factor capabilities. This is a job for an amplifier with greater-than-ordinary current reserves and damping factor so don't just look at the output power of an amp and think 'yes' that is sufficient.

Cheers,

DV
 
Thanks for the comments so far. I have heard the ARC DSi, but not in combo with the Obelisks. And have not heard any of the Lyngdorf gear to even know what it sounds like period. Seems like there are quite a few variants of the class D stuff, each company doing their own brew.

DV-with regard to current delivery and damping, I was looking at the Bel Canto amps, mainly just looking at specs for the sake of information only. I see they are capable of 35 amps, and damping factors typically haven't been a big issue with that class of amp in general. Usually it appears the impedance spec is a factor though.

But I also know it isn't just specs that make or break anything, especially when it comes to Obelisks. But funny as I say this, I used my Naim Uniti-50wpc for a brief period of time on my Obs, and surprisingly, at moderate levels it actually did fairly well, and was quite musical and engaging. But I am sure many would scoff at the notion.

I still want to get a listen to the Dynavectors at some point, but curious about the class D option. Tim
 
Darth Vader said:
Shahinian's bass loading places substantial demands on the amplifier's current-delivery and damping-factor capabilities. This is a job for an amplifier with greater-than-ordinary current reserves and damping factor so don't just look at the output power of an amp and think 'yes' that is sufficient.
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Those criteria are precisely why I went for hypex class D amps.

I doubt that a class D amp would have the necessary requirements.
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Just as with class A and AB, you can't really group all class D amps in one bin. How much current delivery and damping factor do you need?
 
Julf,

How much current delivery and damping factor do you need?
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Oh, I know this one: 150 amps peak into 1 Ohm generating 22,500 Watts or enough power to destroy Alderaan.

Joe
 
A friend has Dynaudio Confidence 5s which are one of the most difficult to drive loudspeakers ever produced. He has a pair of Bel Canto Class D monoblocs and they drive them superbly.

Nic P
 
Joe, the Photon torpedoes are down, but Scotty is working feverishly on this one...Oh wait, Alderaan, damn, different story and different weaponry.... :>)
 
Tim,

Star Wars ships can barely do Warp 1. I think this is all that needs to be said.

Joe
 
True there Joe. Based on many comments about Obelisks, one would think you would have to have enough power/current to drive the entire Starfleet in order to make proper music....
 
I tried a pair of Hypex NC400's. They worked very well. I prefered my NCC200's which seemed to have better imaging to me. To be fair to the Hypexs they wern't being fed with a balanced input, which I understand is essential. If I ever move to a balanced pre I might give them a longer audition. I'm also thinking of auditioning a Devialet 170, only thinking at this stage.
 
I've used Anthem Statement M1 monoblocks with my Arcs and the results were very impressive. 1kW each and a very discreet, well-designed case. Sadly they were only on loan. I wasn't so keep on the Bel Cantos myself but did like the Devialet D-Premier a lot.
 
Dan K said:
I tried a pair of Hypex NC400's. They worked very well. I prefered my NCC200's which seemed to have better imaging to me. To be fair to the Hypexs they wern't being fed with a balanced input, which I understand is essential. If I ever move to a balanced pre I might give them a longer audition. I'm also thinking of auditioning a Devialet 170, only thinking at this stage.
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Should be mentioned that even though the NC400s are very simple DIY, they're so sensitive that any not-so-well-done wiring knocks them off their top performance. I know this one personally, as I recently rewired to quite a step improvement especially in the treble region.

But yes utterly correct, you do need balanced inputs to get the most out of them.

As for damping factor, the Ncores have an extremely high damping factor compared to other amps, and deliver 28amps peak.
 
[QUOTE=TimF;2127719

But I also know it isn't just specs that make or break anything, especially when it comes to Obelisks. But funny as I say this, I used my Naim Uniti-50wpc for a brief period of time on my Obs, and surprisingly, at moderate levels it actually did fairly well, and was quite musical and engaging. But I am sure many would scoff at the notion.

Tim

I ran my Obelisks with my Nait 5i for a short time and was amazed at how good it did as long as it wasn't pushed. First rate sound. I've never mentioned this before for fear of the audio abuse that might have come........but since you've given me some cover!:)
 
I'm listening to a Wagner live broadcast on R3 through a Class D amp with 300,000uF of psu capacitance, into demanding speakers. I'd characterise the grip over the speakers as being in balls of steel territory.
 
If you're looking for a high-current/high-damping-factor digital amplification solution for those Obelisks, you may want to consider Wyred4Sound's monoblocks - their SX-500 (250 watts into 8ohms with max current of 35 amps) or their SX-1000 (500 watts into 8ohms with max current of 40 amps).

UK dealer: Item Audio
Website: Item Audio Wyred4Sound Price Page

Pricing:
SX-500 = GBP 850.00 per monoblock (GBP 1,700.00 per pair)
SX-1000 = GBP 1,050 per monoblock (GBP 2,100.00 per pair)

These mono amps use the latest iteration of the icePOWER modules

The SX-500s (virtually the same as my Jeff Rowland Model 201s) should be more than adequate.

Dave
 
Anyone care to characterise the sound of the various designs, hypex, ice etc? I've only heard Chapter Audio and not sure which type he uses.
 
I tried a class d amp (or read about it) about one once. Didn't like it. I'm a disbeliever :)
 
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