I guess SIL 994 and LM4562 will work equally hard as the load is well within their capabilities.
No it's like comparing a lawn mower engine to a Bugatti Veyron engine. Not even comparable. The 994's run in pure class A up to 7mA beyond the max rating of the LN4562 how many mA can a LM4562 sink and source biased into class A?
Yes it would fizzle into a puff of smoke within seconds driving the NC500's biased into class A.
No, it can still work with an external current source biassing it into classA without vanishing into a melted pile of hot silicon.
I think I would rather stick with the SIL-994 that runs in pure class A up to 30mA into a 75 ohm load without even flinching, and 0.0003% THD.
Yes it would likely run the power bill through the roof. Audiophiles are going to go bankrupt.
So you figure the evaluation buffer is only about 15% efficient?
That is the recommended power supply voltage to drive the Vsig on the board. It is not current.
Oh well not sure what typical is implying there. Are they assuming everyone has the same speakers and only listens to music at the same levels? I guess I'm not typical as I sometimes like to listen to the Sheffield drum and track disk at 115dB. I guess those boards wouldn't be appropriate for me.
it has been stated several times that NC500 amp requires "only" 10mA for it's full operation, why are you still insisting we all need opamp capable of 200mA to get best out of it? it's complete overkill...
It's been stated where? All I see is the buffer draws 60mA from the regulators. Assuming only 10mA of that makes it to the amps, that's assuming the buffer circuit is only 15% efficient.
Perhaps if the phenomenal sound quality of having an opamp that can drive the NC-500's to full output in pure class A, and still only idling is too much, people can look at other options which use IC opamp based buffers such as the Bel Canto Ref600m.
http://www.soundstagehifi.com/index...el-canto-design-e-one-ref600m-mono-amplifiers
Please realize that your efficiency argument is a straw man.
We have told you, many times, how you can calculate, using grade 7 elementary school math and physics, the actual values of nc500 input current. I also suggest you check out figure 2 (under paragraph 11.2 in the Hypex NC500 OEM data sheet (R4)), provided specifically to help estimate input current.
Oh, and that same data sheet, under 8.3, states "Note that the input impedance is fairly low meaning that minimalist discrete circuits or valve input stages won't work. All op amps commonly used in audio can handle them though".
Ah, so any value described as "typical" by Hypex is useless for you, as you are not "typical"?
I'm just wondering from a layman's perspective, if 60mA is being drawn from the regs, yet only 10mA of that is making it to the NC-500's, where did the other 50mA go?