Hierzu noch Infos direkt von JL:
"The core amplifier technology in the HD amplifiers is completely different from the IcePower design being used by Alpine, Pioneer, Eclipse and others.
Our technology was originally developed at Univ. of California-Irvine (a powerhouse in power electronics engineering) and has been commercialized by a California company called PowerPhysics. It is already in use in some very highly regarded professional audio products, but we have licensed it exclusively for the 12V market. In fact, we will also use this amplification in our upcoming full-range powered monitors for Home Theater and pro applications.
Ok, that's the background... what makes it special:
I will assume you have a basic understanding of how Class D amps operate... If not, let me know and I will go back and explain that better.
There are a number of problems that make high performance in full-range Class D amps difficult, and you can band-aid some of them, but our method addresses all of these problems at once.
The answer lies in how you decide when to switch, when to change from one polarity to the other. Typical Class D uses a “blind” method – one that is ignorant of real-world problems and only works well if these problems don't exist. In other words, it says, “this should be correct”. (This is like a quarterback throwing a pass to where the receiver should be.) These real-world problems include non-linearities in the power supply, switching lag, pulse width errors, dead time, device non-linearities, etc.
A switching “cycle” in a Class D amp is a pair of rectangular pulses, one positive, one negative. The Single Cycle Control method measures the output continuously and makes the decision to switch, ending the cycle, when the output is correct. Because it measures the output, it takes into account all of the problems with changing supply voltage, delays, finite switching time, and so forth. In contrast to a “blind” method, Single Cycle Control knows that the output is correct. In other words, the QB can tell that the receiver got jammed at the line of scrimmage and adjust the timing of the throw to still complete the pass.
The output that SSC looks for is the area of the pair of pulses, actually, the area of the positive pulse minus the area of the negative pulse. This area IS the output at the end of the cycle, and it doesn't matter that various problems affect the shape of these pulses, as long as the area is correct.
SSC gets the output exact right over 400,000 times per second (once per switching cycle). It's as if you had problem-fixing feedback that was equally effective all across the audio band. It's elegant, and much simpler than applying a bunch of complex “band-aids” with the drawbacks that go along. The SSC approach is a bit more expensive to implement than the IcePower designs, but we feel the benefits are worth it as they really create what we consider a reference-grade product with all the efficiency and packaging advantages of Class D. In fact, I invite you to compare the sound of the HD's against any full-range amp at any price, of any type. They sound absolutely wonderful.
The HD's also have a more complete signal processing package than the PDX amps (variable slope crossover filters, preamp outputs, remote level control, polarity switch on the mono amp, infrasonic filter on the mono amp). And they're smaller than the PDX's by 15%, too (over 1/2-inch shorter in height).
HD's also feature a tightly regulated power supply with full R.I.P.S. implementation (equal power at any impedance from 1.5-4 ohms per ch. and with any supply voltage from 11V-14.5V).
Another difference is that our 600W monoblock is a full-range amp, which makes my inner audiophile salivate with visions of unlimited headroom.
So, as you can see, there are quite a few differences between the HD's and other small amps on the market.
Best regards,
Manville Smith
JL Audio, Inc."
Quelle:
http://forum.elitecaraudio.com/showthre ... did=146523
Grüße, Pit
