sanyofreak
Active Member
Nakdoc said:Consider your bow shot. Your generous analysis has huge errors...sorry.
An ideal amplifier, like the Levinson ML 2 (25w RMS), will deliver twice the current if the impedance is halved, and twice again if halved again. So this amp is 25W into 8 ohm, 50W into 4, 100W into 2, 200W into 1....etc. The ML2 is also a nice example because it is class A. The same current flows across the outputs with or without a load. This enables the amp to drive short circuits with no damage.
I said before,
I'll say again for my sake, It is EXTRAORDINARY to find a SS amp that perfectly doubles its output with each halving of the load. If You find one, It will be very expensive.(Thats what I said) I've quickly checked out the Levinson ML 2, And as we all would expect, by anyone's stretch that I know of - this is an extraordinary amp. I dont know what the MSRP was on this amp, but when it is revealed I know I will agree with my perception - very expensive. It's also a 25WPC amp that appears to weigh in at well over 50 pounds - and thats a monoblock folks - ya need two fer stereo, You got'em, and I'll definitely consider You on the Extreme "High end" as far as price goes. You'll also likely have a pair of amps that weigh in at more than a G-22000(docked), but is (only) 25WPC at 8 ohms. See what I'm gettin at ?? Perfect doubling IS a herculean feat, and in no way would I consider an amp that does not acheive this spec to have any corners cut, on that premise alone.
The number one item that makes the ML 2's specification possible - is this.....It incorporates a fully regulated power supply, trust me, the perfect doubling feat simply cannot and will not be done on this earth without that feature. (in a class AB amp) Even if my dual 500VA transformers and outrageous filtering were behind a 10WPC amp, without regulation, it still 'prolly will not double its power with a halving of load. The expense of a regulated supply that can deliver the power necessary for an audio amp is definitely not only beyond ANY receiver ever built, but also beyond most seperates.
I agree the Concept is a wonderful piece of gear, but with a rating of 165W/Ch into 8 ohms, would not perfect doubling be more like 330 W/Ch into 4 ohms ?? 250 is more than half the watts over its 8 ohm rating, not a far cry, but a cry from the ideal, and this is excellent performance still.
Now here's a real tangent - in an amp like the Levinson ML 2, can anyone guess what the amps Dynamic headroom spec is ???
I've spoken of this before.
But to agree with EW, this is still a worthwhile and informative discussion, and 240's points are definitely something to consider with multiple 8 ohm speakers or driving a single pair of 4 ohm rated speakers.
Other points still are valid, remember, its the actual Junction inside the BJT's case that does all the magic, and all the smoke if she blows. Every power transistor has a spec on how well the case itself is thermally "coupled" to the Silicon junction. Then, the case has to be able to conduct that heat to the sink itself, (use your grease or goop)and finally the sink to "air" thermal efficiency. Somewhere out there is a member Hotgas, who can help us with all of this type of physics, but no matter, If that junction cant transfer its dissipation to the case efficiently enough - death, so in some cases fan cooling will also not be enough protection,because the junction cant shed its heat to the case/heatsink/air, quickly enough. Like EW says, if Your listening too loud, in a nutshell.
Great exchange and please, no offense to anyone here, and I will say that the ML 2 and the Concept 16.5 are both awesome products.