On 13 Nov, 11:11, "Phil Allison" wrote:
"Trevor Wilson"
Does anyone have a schematic for a Luxman SQ38D? I mostly require info on
the tone amp section. The one I have has been modified and I need to
restore it to standard.
** The " SQ38D" *was released in Japan in 1965 *- *do you really have one of
them ?
A long series of *" SQ38 " *amps were released including the "SQ-38D" in
1998.
http://www.onahighernote.com/luxman/?c=5&id=45
Earlier models had triode output valves ( 6RA8s ) made in Japan, later ones
uses regular 6BQ5s.
Luxman schems were always near impossible to obtain - certainly so here in
Australia.
.... *Phil
What's wrong with Trevor? All he has to do is sit there for awhile and
draw the schematic from what he sees, and then work out how it works,
or should work, bearing in mind any mods he should be able to see, and
then, once he understands what he's doing, he can properly check the
darn thing out. Even with a schematic, a good tube tech draws the
schematic anyway, and completely familiarizes himself where everything
is on the schematic. Its all so much more logical than trying to draw
a Luxman SS amp circuit. I've had 3 tubed Luxmans come to me for a
fix, one had 6868, and they were so expensive in 1995 that I replaced
them with EL34 & sockets after making the case taller. The next had
some strange OP tetrode but had two blown OPTs, so its still here
after 12 years. The next can with strange 12 pin tubes with 50V
heaters and a missing OPT which another tech had lost, so the OPT
musta fused. It stayed awhile, then I reused the chassis for something
far better of my own design with 2 x EL34, and some better wound-in-Oz
PT and OPTs. I reused a choke. Below Trev says he want to sell the
Luxman for $2,000 after paying hundreds for new rare tubes unlikely to
be available when the next time comes arounf for replacement. What's
anyone got for 2 grand? Just another lack lustre tube amp, with maybe
very used/traumatised OPTs after possible episodes of overheating
tubes. Luxmans are supposed to have "Mystique", good "Karma" or "Aura"
but I don't see it. I get a number of ancient POS amps coming here for
singing lessons and quit-smoking therapy. All very sacred old brands,
but not one is a sacred cow, so I usually gut the lot and start all
over again. Just finished a pair of POS Jadis SE300B amps. No other
way to make 'em behave.
Patrick Turner.