2. amps-preamps
  3. 150690-2029

What Class D amps will drive a 2 ohm load

Just asking.

I see specs into 4 ohms but nothing into difficult speaker loads (like Thiel CS5's).

Thanks for listening, 

Dsper


dsper
joysjane's avatar
joysjane
165 posts
 
One of the reasons I’d like to give these a go...
Specifications
  • Design: Monoblock Power Amplifier, Class D.
  • Power Output: 570 Watts RMS into 8 Ohms, 1,140 Watts RMS into 4 Ohms.
  • MFR: 20 Hz – 20 kHz, ± 0.4 dB.
  • THD+N: 0.2% at Rated Output.
  • IMD: (CCIF): 0.0005%
  • Efficiency: 79%
  • Sensitivity: 2.95 Volts.
  • Output Impedance: 0.005 Ohms.

It’s gonna need every bit of those ratings to drive the 9’s!

Without dropping a name I was advised they’re rated into 2-Ohms.

It’s worth a go...

georgehifi's avatar
georgehifi
10,312 posts
 
joysjane
Don’t think your gunna like this

It seems the WFS SX-1000 uses the same B&O 1000ASP ICEpower module as the Bel Canto Ref1000M monoblocks.

Stereophile say they turned them selves off when presented with a 2ohm load, which easier than the Kappa 9’s load which is a below 1ohm horror load.
"Ref1000M monoblock offers very high power from its diminutive chassis. It does work best with higher-impedance loudspeakers"

Maybe it’s time to sell the Kappa 9 if you really need to go class-D

My friend with Infinity Renaissance 90 little easier load than the 9’s was trying to do the same with Class-D’s, didn’t work out either, went back to his big Krell, which luckily he didn’t sell.

Cheers George

golfnutz
231 posts
 

Yep, WFS SX-1000 uses those same modules.

Spec sheet specifies 2.0 ohm minimum load, as well as 40 amp current (peak). Unlike the Icepower 1200AS1/2 being rated at 2.7 ohms.

Also included in the specs:

Overload Protection - In case of high-amplitude continuous low frequency signals in loads lower than 4 ohms the power supply may not be able to deliver the required amount of power to the amplifier and the supply voltage will drop. The overload protection circuit will then lower the threshold of the input soft clipping circuit until the output power has been reduced to an acceptable level. As a result the amplifier will not shut down because of under voltage and the music will still be playing but with a softly shaped audio signal.
 

dsper OP
663 posts
 
Hi joysjane,

FWIW as it might not be the same animal, I have a five year old W4S ST1000 and it could play Maggie 3.6's loud but with no control of the bass.

It had trouble with Thiel CS3.6's and was a joke with the CS5's.

In my set-up, a Coda CS (300 WPC 8 Ohms, 600 wpc 4 ohms) did much better but got constrained/harsh with the CS5's at higher volumes.

My current amp, a McCormack DNA-500, is effortless with the CS5's. Any change now would be to eliminate my perception that I think I still hear a bit of grain or there is a lack of the sound coming out of a black silence. Based on listening to a X350, Pass might be better but they are hot and huge.

Again, FWIW.

Thanks for listening,

Dsper
golfnutz
231 posts
 

It had trouble with Thiel CS3.6's and was a joke with the CS5's.

So the Icepower 1000ASP had trouble with Thiel CS3.6. Well, they are a tough load through most of the frequency range.

The 1000ASP should have an easier time with the Thiel CS3.6 than the 1200AS1/2 since the ratings are 2.0 ohm minimum load and 40 amps peak, vs 2.7 ohm and 38 amps peak for the 1200AS1/2.

The 1200AS2 didn't pair that well with my Wilson Watt/Puppy's. If you compared the 1200AS2 to my Class A amps, it was no contest really.

To be honest, I'm not sold on what @cascadesphil is saying about his EVS1200 amp being suitable for his Thiel CS3.6 speakers(based on Icepower 1200AS1 modules). I suspect he is using subwoofer's and this is masking the issues. It's too bad he never had a decent amp as a reference point to compare. Both his previous amps weren't sufficient for those speakers either. He should have paid attention to the Stereophile reviews for those amps as they were only mediocre. This is just my opinion. I'm sure the Icepower 1200AS1/2 do well with higher impedance speakers.


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