"David Looser" wrote in message
...
"Trevor Wilson" wrote

**DBTs are not metaphysical. They allow REAL differences to be heard.
Tell me about your experiences with DBTs between MOSFET and BJT amps.

I'd be interested to know how these DBTs were conducted. How many
listeners did you use?

**10. I arranged for a person who had no knowledge of which amp (he was no
present at set-up time) was which to throw the switch, whilst keeping a
record of which position the switch was in at each change. I set the
equipment up and was present for the test, but took no part.

, how were they recruited, how much did they know about the
purpose of the test? etc.

**They only knew that there might be a change in the system when the light
changed from green to red. The listeners were all those who considered
themselves to be audiophiles. They were not 'people off the street'. I was
already familiar with the listening preferences of each. They were tested in
groups of two, over a period of several days.

I performed the test, because I heard about these "new" (back in the early
1980s) MOSFET amps and how wonderful they allegedly were. I was surprised at
how bad they sounded, despite glowing reviews in places like Stereophile. I
decided to recruit others to see if their perceptions agreed with mine. They
did. All listeners reported similar findings. The MOSFET amps sounded
'compressed' and lacking in dynamics.


--
Trevor Wilson
www.rageaudio.com.au