"Arny Krueger" wrote in message
...
"Robert Morein" wrote in message

wrote in message
oups.com...

Arny Krueger wrote: snip

It is true that cheap-ass tubed equipment is far more technically
deficient than some of the expensive stuff. There's no reason why a
price-is-no-object tubed amp can't sound good and accurate when that
high
price is invested in a technically sophisticated way.


That's exactly what I said. If you are willing to spend money either
tubes or solid state may be used to build good amplifiers. Good solid
state ones IMO aren't cheap either. They need (IMO) big heat sinks
and quiet low impedance power supplies.

Partly true.

A price-no-object tubed amp can sound as good in many ways. That does
not mean they are equivalent.

In his sad quest for the false appearance of technical competence, the
Morein grotesquely distorts what I said and then tries to make a big show
out of *correcting* his own statements as if they were mine.

Obviously I never said that tubed amps and SS amps could be equivalent. I
said

"There's no reason why a price-is-no-object tubed amp can't sound good
and
accurate when that high
price is invested in a technically sophisticated way."

But output transformer saturation leads to an inherent high-pass
filter that cannot be eliminated, unless on goes with something like
the Futerman OTL design.

Regrettibly, the Morein confuses two common output transformer failings.

(1) Core saturation, which causes nonlinear distortion (e.g., THD and IM).
(2) Leakage capacitance, which causes loss of high frequency response.

If you could read, this would be unnecessary. I said, high pass filter, not
low pass filter. I was not commenting on the loss of high frequency
response. With respect to loss of low frequency response:
1.The induced voltage in a transformer is proportional to d Phi/d t, the
rate of flux change in the core.
2.The lower the applied frequency, the slower the flux change.
3.Therefore, the amplifier compensates, by it's feedback loop, by increasing
the rate of flux change, ie., drive throught the transformer, to maintain
flat voltage response on the output winding.
4.Therefore, at lower frequencies, the maximum flux value through the core
is higher for a particular output.
5.Therefore, the lower the frequency, the lower the output at which the core
saturates.
6.Thus, the low frequency output of a transformer coupled amplifier is
limited by mass of the transformer, which determines the maximum flux.
7.This accounts for the fact that tube amplifiers can have wide bandwidth at
low power levels, but the bandwidth contracts at higher power levels.
8.Transistor amplifiers exhibit this reduction in bandwidth with power
increase to a much smaller degree.