current versus watts

" The amount of current that flows through the POWER SUPPLY when it is shorted out for 10 milliseconds. That's the official spec. There are a number of tube amps with ratings that high. So when you see the idea of 'current reserve' being bandied about, keep this in mind. "

Thank you Athmospere, you are absolutely right. Spectron also makes the same point (well, their reserve of 65A lasts 500 msec with peak power of 3500 watts per channel)

I would add to your comments that luck of needed power (voltage or current) leads to distortions and you and Spectron wrote that this type of distortions (particularly in ss amps) is odd order harmonics producing ear piercing sound.

Thank you again!

Rafael

".... output current when the amp is outputting 300W. You should realize that such an event is unlikely to occur frequently..."

Well, measured (MEASURED!!!!) peak power needed to drive B&W 805 bookshelf speakers at musical peaks waw 3500 watts i.e. not three hundred but more then three thousand watts and for 87.5 dB sensitivity bookshelf speakers.

Only Simon Thacher from Spectron (to the best of my knowledge) is trying to "connect" specs of their amp with its musicality and many, me including, compare their amps to the best tube amplifiers.

The problem is not in specs. The problem to read them and understand them. The problem that many of not most amp producers show misleading specs like we discussed above peak current for 20 msec or displaying distrotions at low (typical number is 10 watts) output and not full output and at 1kHz only etc etc.

So, yes - you are better off listening to the component but it does not hurt to understand too...

John and Simon's philosophy is iltra low distortions and then you hear real (well recorded...) music without ear piercing or euphinic colorations.

Rafael

"use of negative feedback is violating one of the fundamental rules of human hearing perception. "

Hello Ralph,

I spoke with Simon Thacher from Spectron and he is in full agreement with you as it relates to negative feedback in conventional amplifier.

He said that you are absolutely right and poor neagtive feedback, ripples from the power supplies and few other sources of odd harmonic distortions are "music soul killers" i.e. its not so much obsuring detail by even order harmonics as ear-piercing odd order harmonics.

Yet, Spectron rely heavily on global feedback. He explaiend that the crucial factor in negative feedback is transit time, the amount of time it takes from when an error is detected at the input until it is corrected at the output.

Thacher claims that Spectron use much faster digital logic circuits then anybody in the world. Their amp's transit time is less then 200 nanoseconds. Such an ultra-short transit time allows the amplifier to correct for many small errors; and the control loop can follow the input much more accurately WITHOUT generation of many odd (and even) order harmonic distortions and this is the main reason for positive "musical" reviews their amp receive.

All The Best
Rafael