Originally Posted by M Code
The latest Class D solutions are excellent, and sonic ally they are superb.
Yet today still are many who are sceptical of their electrical performance.
I will recap for you a personal experience for this subject..
About 3 years back, I was asked by the president of a very large US based audio brand to organize an audio comparison demo of the latest Class D amplifiers vs. high quality Class A-B amplifiers. I took 4 of the latest Class D solutions (Ice, Zetex, Intersil, TI) and a high-end Class A-B amplifier of the client's brand. I level matched each driving a pair of well-known high-end loudspeakers that sold for about $6,000 and used a low-loss speaker relay switching system.
The listening panel was made up of the brand's golden-ears, their marketing guys and president, our objective was to compare each amplifier and our basic question was Which amplifier sounded the best?
Note that the listening panel did not know which amplifier was playing, after 3hours of playing these each member of the listening panel could not
tell any difference between each amplifier.
The end-conclusion was that all
of the latest Class D solutions are capable of delivering a high-quality, neutral, uncolored response, equal to a comparable, quality Class A-B amplifier. There remains some biases over the smaller footprint of the Class D solutions rather than massive heat sinks. But in this face-off there was no discernible audible differences.
Just my $0.02...
Great thread Michael!
M Code that sounds like a good test.
I did my own comparison to try out the D-Sonic MAGNUM 2500-7 (Cox 250x4) amp. I had a fried bring over is Outlaw 200Wx5 amp and also include my 10 year old Sunfire Cinema Grand Signature (400x5) amp. Of course, none of these rating a continous all channels driven.
We listened at moderate (peaks in the low 90DB range) and what I will call comforatable (in the low 80 DB range).
The Outlaw seemed to have the most impact, detail, and had great speed.
The D-Sonic also was detailed but seemed rolled off. It upper end I liked, but my friend and wife did not like it as well as the others.
The Sunfire was the least bright of all the amps, I got the impression that was not as fast (which is the best way I can think of describing it).
Where the D-Sonic really fell down was on the lower end. It did not provide the bass that the other amps had. The Sunfire had slightly more than the Outlaw. My speakers a Revel Salon's which are not very efficient (86 DB) and deliver bass down in the low 20hz range. Surprisingly, this was at relatively low playing levels. The impact was there but it did not sustain the bass as well as the others. I ended up returning it. I am no expert, but I did read some articles that indicated that these amps can suffer from phase issues which could explain the lack of bass that I was experiencing. I do not think it was defective because I tried three different sets of channels.
Since then, when I read a review, I also pay attention to the speakers used. Very often the speakers do not go much below 35Hz so I take that into account. Also, when I here: the bass was fast, tight, and not bloated, I take that as not much bass
I sold my Sunfire Cinema Grand Signature and bought a used Sunfire 7400 (400x7) amp and bi-amped my Revels since I had two extra channels. It couldn't hurt. I am very happy with the Sunfire.
I really wanted to love the ICE amp technology (and still do), but I would not buy one without a low risk in-house trial.
H-Class amps seem to provide the best of both worlds, low power and heat with the performance of an A/B amp.