After a few months of trouble free operation, I went to turn on the (RCA
MI-12188A) amps last night, and another Chinese 807 shorted out, went
bright blue, and ended its life. A used 807 brought the system back to
life, but it looks like I'll be changing things sooner rather than
later. Thanks again to the group for your input on this issue, and for
bettering my understanding of thermal runaway.

Max

"Max Holubitsky" wrote...

After a few months of trouble free operation, I
went to turn on the (RCA MI-12188A) amps
last night, and another Chinese 807 shorted out,
went bright blue, and ended its life. A used 807
brought the system back to life, but it looks like
I'll be changing things sooner rather than later.
Thanks again to the group for your input on this
issue, and for bettering my understanding of
thermal runaway.

Hi Max,

If you (or anyone) need 807s, I have some RCAs
and I have some Russian made 807s that are very
good tubes. Let me know if you can use them, the
Russian tubes in particular are a bargain, $8.50 ea.

Jim McShane
Need Tubes? Got a H-K Citation (Pre) Amp?
Check http://pages.prodigy.net/jimmcshane
Repro knobs for Citation gear in stock!

On Fri, 16 Jan 2004 11:16:09 -0700, Max Holubitsky
wrote:

After a few months of trouble free operation, I went to turn on the (RCA
MI-12188A) amps last night, and another Chinese 807 shorted out, went
bright blue, and ended its life. A used 807 brought the system back to
life, but it looks like I'll be changing things sooner rather than
later. Thanks again to the group for your input on this issue, and for
bettering my understanding of thermal runaway.

Max

You might find that an industrial equivalent, the 5B254M (I think!) is
more reliable. They were manufactured with the appropriate base as
direct equivalents by ITT for use in the Decca Navigator stations. An
extremely robust and reliable valve.
--
ajb

If the 'self' is an illusion, who is being fooled?

Max Holubitsky wrote in message ...
After a few months of trouble free operation, I went to turn on the (RCA
MI-12188A) amps last night, and another Chinese 807 shorted out, went
bright blue, and ended its life.

Dear Max

Lots of fine NOS USA made 807 available from www.c20store.com

David

ajb said:

You might find that an industrial equivalent, the 5B254M (I think!) is
more reliable. They were manufactured with the appropriate base as
direct equivalents by ITT for use in the Decca Navigator stations. An
extremely robust and reliable valve.

I've found the RCA 807 one of the most reliable and sturdy tubes
that's out there.
Only the ATS25 (military version of the 807 with white ceramic base)
might be better.

--
Sander deWaal
Vacuum Audio Consultancy