Why Don't We See More High Current Electronics?

Irv, thank you for offering the words of reconciliation to Grant.

03-16-11: Irvrobinson
For a good voltage-source amp with 100w into 8ohms, if the speaker has a peak impedance of 16 ohms into 4KHz the amp will clip at 50w, and if the lowest impedance occurs at 40Hz with 4ohms the amp will clip at 200w, but the frequency response at 50W will still be flat (within the amp's spec) across the entire spectrum up to 50w.

Trick question - what happens if the speaker is reproducing 4KHz and 40Hz *at the same time*?

Well, since one frequency is far higher than the other, there will be instants of time at which their peak amplitudes will simply sum together. If both frequency components have the same amplitude (which is highly unlikely with music), the amp could provide half of its maximum output voltage at each frequency, without clipping. Since for a given impedance power is proportional to volts squared, power delivery at each frequency at the clipping point would be 1/4 of the numbers you cited above: 12.5W at 4kHz, and 50W at 40Hz.

At least, I think so :-)

Regards,
-- Al

Where's kirkus?

He knows more than anybody about this stuff.

Hope he jumps in.

Not sure how this thread deteriorated into a philosophical argument. Typical example of the audiophile niche market.

"High current" has faded as marketing buzz word. That's all. Still continues as a design philosophy. Don't make me name names. Doubling down, well that requires, along with adequate power supplies, a specific kind of circuit and feedback, which happens to be the new buzz word.

There's one brand, to remain nameless but with unusual sincerity, that only tests the amp into 4 ohm power resistors, and only at 1 kHz. They divide that by 2 for the rating into 8 ohms. They also claim stability into 2 ohms. It's a good brand and an impressive amp so I'm not disputing. Just saying that advertised ratings are not real-life, reactive loads.

One can and sometimes does hear in excess of 110 dB. It's not just the volume, but the duration and the frequency that one hears these peaks that are of concern. When it's appropriate, it's nice to have the capability. Some speaker can handle it without significant distortion.

Yeah, we've had this discussion before. Same old same old. Lots of assertions, but no supporting data. Negative feedback is bad because it causes time-domain distortion, distortions we can measure aren't important

Of course there is plenty of supporting data, and the distortions we are talking about *can* be measured, as well as heard.

high output impedance doesn't really affect frequency response linearity.

I don't know where you got that but you did not hear that from me. In fact the whole point of that paper (which now I am guessing you did not read) is that you have to **pay attention** to these things to **prevent** errors in 'frequency response linearity'.

so very high current amps are mostly for people that have more money than sense (like me).

Tube amps are for people even more skewed towards money than sense. ;-)

So, are you saying here that you have a tube amp in your future?? :)