>
>Rich said:
>
>>There may be yet another manufacturing defect since,
>
>Quite possibly. It's not an easy thing to trace, is it?
// Removing the 8877's anode cooler is not all that difficult, and it's
not nearly as stinky as doing a human autopsy. Spotting the cause of
death takes maybe 20-seconds when my 30x magnifier isn't playing hide and
seek.
>The best bet is if you
>ship the amplifier, complete with tube, having done a 'burn in' run for say
100
>hours. The cost of such a burn in (provision of burn in racks, monitoring,
>drivers, loads and so on - even electricity) makes this a bit on the
>expensive side for amateur equipment.
>
>If for any reason you don't test the amplifier with the tube, you've even more
>problems in really deciding if it's a bad amp or a bad tube when the problems
>start appearing out there in the field, and you need a fair number of bad
tubes
>of a certain date code(s) to show up before you know whether or not there's
>really a problem.
>
// The last two 8877s I autopsied seeningly had the aforementioned Eimac
mfg defect -- and the requisite date codes. Neither had any
gold-meltballs stuck to the cathode.
>
cheers, Peter
- R. L. Measures, 805.386.3734,AG6K, www.vcnet.com/measures.
end
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