But this was a junk box effort, which
was good enough satisfy me and to prove that "Danger Dave" didn't know
what he was talking about when he made his original statement that this
sort of amplifier couldn't be built without serious hum. The hum was
better than 80 dB below 1 Watt out, which is better than a good number of
commercial tube amplifiers with power transformers.

Well, Dayuumm... One of the things being a 'repair person' teaches is
that hum-free (very low hum) circuits without mains transformers and
without massive electronics are pretty common, pretty simple and can be
pretty good performers. And the (HFV)L6 series of tubes are
particularly suited to that use. Add such niceties as not using the
chassis as the common rail, input and output transformers and they are
about as safe as anything else out there of a similar general class,
certainly more-so than any AA5.

As to the input transformer being 'designed for the job', that is a
moving target. Imagine the most catastrophic cascade-failure on the
system that would _NOT_ blow the fuse, how much voltage & current that
would deliver to the secondary side of that transformer, and whether it
could take it or not without shorting to the case or to the primary
side. I have not examined your schematic in detail (nor do I know the
specifications to the transformers)... I seem to remember a hand-drawn
sketch. In any case, you are not intending to put this thing into
production, nor are you (apparently) holding it up as an avatar of
all-things-amplifier.

Keep in mind, John, that no one here is 'picking' on Mr. McCoy. Were he
to confine himself to 'being useful' as he seems to believe is the
purpose of other people's lives (at least), he would be mostly welcome
and mostly treated with the respect he deserves. However, he insists in
creating his useless little alliterative fantasies, mostly out of whole
cloth, and is then surprised when he is not so welcome and also treated
with exactly the respect he deserves. With due respect, his magnum-opus
looks like a cook-book recipe assembled with very limited skills under
marginal conditions and no real understanding of the expected results.
For all his pontificating, one would expect Mr. McCoy to be at a
minimum a better mechanic. See, there is something to be said for
'craft'. It makes understanding what one has done infinitely easier, it
sure does help prevent mistakes during the process, and it helps anyone
confronted with the work in the future. It falls back to the
carpenter's motto: Measure twice, cut once. There may never be quite
enough time to do it right... until one is faced with the need to do it
over. Platitudes, perhaps. But they got that way for clear reasons.

Peter Wieck
Wyncote, PA