"Patrick Turner" wrote in message
...
Trevor Wilson wrote:
"Prune" wrote in message
4.76...
"Trevor Wilson" wrote in
:
BTW: Modern transistors are more linear than even the best Triodes.
This is meaningless unless the specific distortion profile is weighted
by
the nonlinear masking effects of the human ear and perceptual
mechanism.
**********. Distortion profiles are dictated by topology, not the
specific
device used. A more linear device will exhibit lower levels of
distortion.
I've already pointed out references elsewhere that THD measurements do
not
in general correlate with human perception of distortion in blind
testing.
**Non-sequitur. The best transistors are more linear than the best
Triodes.
Please propose a test to compare the two.
**For the BJT:
A suitable supply Voltage for Collector and Emitter. Apply a current to the
Base. Vary that current from (say) 1mA to (say) 10 Amps. Graph the result.
For the Triode (or more amusingly) the Pentode:
A suitable supply Voltage for Plate and Cathode. Apply a Voltage to the
Grid. Vary that Voltage from (say) 0 Volts to (say) -50 Volts (or whatever
the limits of the tube are. Graph the result.
A modern power transistor will display a more linear amplification curve
than any tube. And over a much broader range.
I will readily acknowledge that transistors which Jute continually refer to
(2N3055, et al) are not particularly linear devices. Since his experience
appears to be limited to these, quite primitive, devices, it is hardly
surprising that he feels that a tube: "...is the most linear device known to
man." If he ever managed to pull his head out from his own arse, he would
realise that transistor technology has advanced significantly in the last 40
years.
--
Trevor Wilson
www.rageaudio.com.au
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