"John Richards" wrote in message
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"Billy Shears" wrote in message
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Snip...

I don't think anyone has claimed all tube amps sound like all
solid state amps. Do you have a reference for such a claim?

I thought ALL amps which met minimum performance levels (specs?) sounded
the
same as long as they were not pushed beyond their design limits.

When I bought my first solid state amp, I noticed immediately that it seemed
to have a leaner sound with less bass. Being an engineer, I of course
refused to accept this situation without some explanation. I started by
putting a 1 ohm resistor in series with each speaker. Amazing! The sound
of my tube amp was reproduced almost exactly.

I was in "experimental mode" so I went back to the tube amp and connected my
speakers to the 4 ohm tap on the output transformer. Lo and behold, the
lean sound returned, although the output was much lower.

Going back to the transistor amp, I replaced the 1 ohm resistors with 3 ohm
wirewound rheostats. I found out quickly that you could get as much bass
hangover as you wished by dialing in more or less resistance. I should
mention that my speakers were the acoustic suspension type; bass reflex
speakers would have behaved differently. I ended up leaving about 10% (0.3
ohms) in series with the amplifier.

As far as I can tell, the difference between tube and transistor amp sound
is almost entirely a function of the amplifier output impedance.

Norm Strong