"Smarty"
** Bob Carver only ever made transistor amps - notably under the Phase
Linear and Carver brands. It is generally only tube amps that have such high
output impedances that speaker loading affects the response audibly.
Carver actually did also make tube amplifiers, and one of such series is
described here in the link below. Other tube designs by Carver were also
developed and sold.
http://www.carveraudio.com/index.ph...com_virtuemart&Itemid=104&vmcchk=1&Itemid=104
With regard to your comment comparing Carver amps versus tube amps and
their output transformers, I didn't particularly assume Carver's design
was solid state and the reference was not, since I have no reason to
believe this was actually his situation. The comment I previously made
was that Carver's prototype could never ***exactly**** match the
reference amp he was attempting to imitate due to differences between
the two which would not be amenable to simple transfer function /
frequency response / phase response alone. I mentioned examples of
obvious areas where such differences would still show up.
Bob's prototype in this case very well may have been solid state, and
then, to an even greater extent would fail to imitate the reference tube
amplifier, if in fact the reference amplifier was a tube design, in the
specific area of output transformer performance, for the obvious lack of
an output transformer in Bob's amp. Even if Bob was comparing his tube
design to a reference tube design, the nulling method he used would not
show their differences in dynamic performance necessarily either. His
"voicing" strategy also failed to look at intermod, and the more
complete time bandwidth differences which would have been difficult or
impossible for him to really measure years ago for nulling purposes, in
particular FIR, for which no low cost deconvolvers were out there yet. I
believe he used swept sines or possible some more harmonic-rich test
signals, but he was unlikely to have been able to do true and holistic
comparisons with finite impulses and other comprehensive methods now
considered much more common place.
* * Where an audible difference REALLY exists, there will be an easily
measured difference too. This what Bob found and figured he could
emulate with a few passives added to one of his designs. It is not
necessary to match amps so precisely to make them sound
indistinguishable in normal listening circumstances.
I agree strongly. The human hearing system is a relatively inaccurate
tool for hearing fine details which show up glaringly in some very
simple tests and measurements.
