Hi One and all,

I was hoping someone could help, I usually purchase a number of HiFi magazines (Not What) on a monthly basis, I believe in the June edition of HiFi News there was a group test of Class D amps.  Unfortunately I was out of country and unable to purchase that months mag.  It just so happens that I am most interested in purchasing a class D amp in near future.

Did any one read the article? Could you help with which amps were in the group test and the results.

Many thanks

John

I read it but haven't kept it I'm afraid.

These are the notes that I made for the Nuforce forum;

'Very interesting group test in Hifi News.  It's a group test.  The results are as follows for sound quality;

Trichord S300 (Hypex)  (£2400/$4800) 78%
Rotel RB1092 (Icepower) ((£1600/$3200) 75%
Channel Islands D100 (Hypex) (£1595/$3190)72%
Nuforce Ref 9 v2 (Nuforce) (£2300/$4600) 69%
Flying Mole MA-S160 (Flying Mole) (£1196/$2392) 66%

The prices are the ones quoted in the magazine for the UK; it's my rough conversion to US dollars - our prices include 17.5% sales tax.  I've added the manufacturer of the boards in brackets.  I've added the prices so you can see how the units compete in the UK market.

The speakers used for the review were B&W 802D.

These are the comments on the measurements for the Nuforce.  I think Paul Miller did these.

"This proprietary 'self oscillating switching amplifier' achieves close to 165W/8ohm with 320W in to 4 ohm, but btcause its switch-mode PSU is impressively 'stiff', there's virtually no dynamic headroom - just 170W/310W/425W in to 8/4/2 Ohm.  Otherwise, the Reference 9 has a low 0.05Ohm output impedence and flatter response (+1dB at 30-40kHz falling to -2.5dB at 100  kHz) than specified in to 8 Ohm.  The response does vary with load impedence however.
Distortion also varies with load, frequency and power, between 0.16-0.031% through the midrange at 1-100W and up to 0.45% at 20kHz.  Noise is low and S/N ratio wide at 105dB re. 100W."

Basically, HFN isn't big on digital amps in the way that Hifi World has tended to be and I would argue that the setup maybe wasn't optimal.  I've heard most of these amps and I would have probably gone for the Trichord had I been offered these choices.

 In the Nuforce range, the Ref 9SE v2 is the star  (ie. not the one on test).  Bel Canto was a notable absentee.

Personally I think we are missing 'the bigger picture' here, it is of no consequence whose name is on the product, what is important is the technology in use. My first introduction to class 'D' was a cheap kit based on a Texas IC, now almost every IC company makes a class 'D' amp, whether that be for a mobile phone, a PC sound card or a high power disco amp, they are all at it. One thing is certain though none have crossover distortion and that is the difference whatever the name. Oh and another thing don't discount any really cheap products because the technology is cheap to produce but that does not in 'it's own right' make it any less than perfect, Take a look http://diyparadise.com/tripath it appears that we are still in the mentality of 'the emperor has no clothes' etc. Let me spell it out in big letters here YOU WILL NEVER FIND THE TRUTH FROM A MAGAZINE SUPPORTED AND PAID FOR BY SNAKE OIL CONCERNS equally you will never find hi fi nirvana by listening to sales people in the same way we will never find the truth about 911 by listening to the outfit that created it.

Bit of a serious one tonight. John...