On Mon, 13 Dec 2004 23:27:18 +0200, "Iain M Churches"
wrote:

I would be interested to know the phase response
of a high end SS amp (OK, I know, they are ALL high end:-)
at 20Hz and say 20kHz, or more points if the info is
available.

If someone can supply me with some figs (from say the
legendary Krell:-) I cold use these a benchmark for the
measurements of my own amp.

It obviously depends on the bandwidth of the amp, which doesn't have
much to do with 'high end' credentials. A Naim amp for instance is
specifically designed to have limited bandwidth, and will have phase
angles of around 10-20 degrees at 20Hz and 20-30 degrees at 20kHz. At
the other extreme, a Spectral will have phase angles of less than five
degrees at these frequencies. My own Audiolab 8000P measures about 5-7
degrees at 20Hz and 8-10 degrees at 20kHz (approximated due to being
measured on a 'scope, since I don't have a vector voltmeter). The
Krell is about the same. Some SS amps are DC coupled, which will give
them zero phase angle at 20Hz.

The only thing 'legendary' about the classic Krells is that they
operate in Class A at their 8 ohm rated output, and that they double
that rated output for each halving of impedance down to 1 ohm.
Otherwise, they are not especially wideband or especially low
distortion. They are however, like most good SS amps and a very few
valve amps, sonically transparent.
--

Stewart Pinkerton | Music is Art - Audio is Engineering