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RE: picture of Dennis' amp

That would be 2002, I believe. No
doubt it's still performing perfectly somewhere.

Note the 3-dimensional wiring. Photos are
only 2-dimensional, so the reasoning behind
the build may seem obscure. The chassis may look
crowded and not "neat". It is all done deliberately
in 3 dimensions, not 2. This is still
the way to get max. performance-- even today.

When someone starts bundling and stacking
wiring to be "neat", the most enticing, lovely,
most dynamically contrasting parts of music disappear--
into the wiring.

The concept of direct-coupling 2 tubes together
is not new-- as pointed out, thank you all.

Everything else was not done to impress
anyone, or to use newer, cleaner-looking parts
arrangements. Instead, grounds were run to the
areas needed with 12ga. silver-teflon wiring.

Signal paths for components were made as short as possible.

The bottom plate of this old amp doubled as an effective
isolation platform. The plate used brass standoffs and
screws.

The standoffs were tapered to eliminate unwanted vibrations.

High-quality parts were used throughout. R.F. chokes
and small value caps were used to clean-up power for
the driver stage. The reasoning was simple: the amp-factor
of the driver tube is 100. The output tube is only around 4.

Logic tells us that the power for the driver tube must be
superior-- to that of the output tube-- much cleaner,
but still delivered quickly upon pulse demand, with
plenty of low-DCR power.

In this old amp, all of that was accomplished.

Any kind of voltage or current regulation that is not
100% passive will leave it's own distasteful sonic
imprints, so the only regulating parts are capacitors
and R.F. chokes-- and of course-- the main PS chokes..

A super-heavy steel chassis was used to minimize
chassis flex & vibration. Carling double pole,
single throw motor switch was used for the A.C. power.
ALL 4 switch poles were used. Why? Parallel contacts
at each pole greatly reduce diode effects generated
with single-pole switches. The sonic difference is audible
if everything else contributes to good sonic transparency.

Lots of expensive brass hardware was used throughout.
Why? The whole effort sounds FAR better-- in every way
that music plays.

The use of a 20-amp A.C. inlet on the chassis helps. Why?
The plug blades are wider and beefier. Result? FAR better
dynamic performance. Why, when a 15-amp IEC inlet far
exceeds the actual household power used?-- that we can
calculate, that is. Then why does everything you use a 20-amp
inlet on sound more dynamic?

Is there something going on that we can't calculate?
Of course there is. There are always things we can't
calculate-- that's nothing new at all.

The old amp was designed for the AVVT mesh-plate 2A3
output tube--a GREAT, but fragile music reproducer,
that is not available today, but any 2A3 can be run in this
old design. The TRUE mesh-plate (not a phony plate
with holes drilled in it, but a truly woven plate
assembly-- made it mandatory to treat this tube with
respect, so it could last. Anyone who runs this AVVT tube
at 60 milliamps is an idiot..

This tube gives world-beating performance when idled
at 10.4 to 10.8 watts total dissipation, NOT 15 watts,
as is the commom but WRONG 2A3 operating point given by
people and engineers who don't know anything but
calculations determined by loadlines and plate curve
charts.

I determine op. points by what the TUBE needs. Interestingly,
JacMusic had recommended 11 watts total dissipation-- I
found that out 2 years later. I had bought 40 of the
best AVVT meshies earlier. I never regretted that, and
NO ONE has ever lost one of these awesome tubes in one
of those old amps.

Time changes. But the willingness to do things right
is timeless, regardless of who disagrees.

Well. it's been 19 years since that model-- 32 years
since 1989 and improvements continue to
be made. But one thing remains: the basic
circuit and ideas are ancient------------ and superior.

-Dennis-




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