[Arny Krueger]

"William Sommerwerck" wrote in
message

* In this case, I wouldn't have caught the problem. It
turned out that the Dayton-Wright preamp used switches
that were very good at generating RF when opened or
closed. The RF caused the triple-diffused output devices
in the Lux 5M50 to melt from tertiary breakdown, a known
problem with this power amp. (Ironically, Mike Wright was
aware of the RF problem with the preamp, and had added
holes to the PC board for suppression caps.
Unfortunately, the holes were not populated.) This was
not the first nor the last time this happened; the next
time was my own stupid fault.

The real problem is that both the DW preamp and the Lux power amp were just
more examples of poorly-designed high end junk.

The world is full of fine-sounding preamps that don't create RF-rich
transients when you operate their controls. Many of them create no audible
transients at all! The world is similarly full of fine-sounding power amps
that don't melt down every time you drive them with a few transients, or
even a lot of transients.

It would be interesting to know what fraction of the total production of
Dayton-Wright audio products are still in service. It's my recollection
that DW briefly rose to fame on the strength of an interesting idea with a
lot of potential - sealing electrostatic speaker elements in thin plastic
envelopes full of an insulating gas. Unfortunately, they were also the
reactive loads from #&!! and could and did fail frequently in actual use.

As far as the fail-o-matic Lux power amp went, Lux had been around for a
long time even way back then. They should have known better. Apparently
their transition from tubes to solid state was not smooth. Lots of people
built very durable power amps with triple-diffused output devices. No doubt
Lux figured it out, or simply went out of business due to their technical
incompetence.