Hi all,

Can anyone tell me the tube line up in the Luxman SQ 65 integrated hi-fi
mp - the model dates from the mid 1960s.




........... Phil

"Phil Allison" wrote in message
...
Hi all,

Can anyone tell me the tube line up in the Luxman SQ 65 integrated hi-fi
mp - the model dates from the mid 1960s.


**7868 X 4 outputs.
6DT8 X 3
12AX7 X 2
6AU6 X 2

The tube types are stamped into the chassis. Clean the dust off, you'll find
the numbers.

I have one with a smoked PWR TX. Output TXs are fine.


--
Trevor Wilson
www.rageaudio.com.au

"Trevor Wilson"

"Phil Allison"

Can anyone tell me the tube line up in the Luxman SQ 65 integrated hi-fi
mp - the model dates from the mid 1960s.


**7868 X 4 outputs.
6DT8 X 3
12AX7 X 2
6AU6 X 2

The tube types are stamped into the chassis. Clean the dust off, you'll
find
the numbers.

I have one with a smoked PWR TX. Output TXs are fine.


** I'll keep that in mind - now where do you get 4 x 7868s in new
condition ??





............. Phil

"Phil Allison" wrote in message
...

"Trevor Wilson"

"Phil Allison"

Can anyone tell me the tube line up in the Luxman SQ 65 integrated
hi-fi
mp - the model dates from the mid 1960s.


**7868 X 4 outputs.
6DT8 X 3
12AX7 X 2
6AU6 X 2

The tube types are stamped into the chassis. Clean the dust off, you'll
find
the numbers.

I have one with a smoked PWR TX. Output TXs are fine.


** I'll keep that in mind - now where do you get 4 x 7868s in new
condition ??

**Buggered if I know. Luxman were notorious for using oddball (but very
good) tubes. Last one I rebuilt I had to use 6550 as triodes.


--
Trevor Wilson
www.rageaudio.com.au

http://www.tubesandmore.com/ Search for 7868.

keithw...


"Phil Allison" wrote in message
...

"Trevor Wilson"

"Phil Allison"

Can anyone tell me the tube line up in the Luxman SQ 65 integrated
hi-fi
mp - the model dates from the mid 1960s.


**7868 X 4 outputs.
6DT8 X 3
12AX7 X 2
6AU6 X 2

The tube types are stamped into the chassis. Clean the dust off, you'll
find
the numbers.

I have one with a smoked PWR TX. Output TXs are fine.


** I'll keep that in mind - now where do you get 4 x 7868s in new
condition ??

"Phil Allison" schreef in bericht
...

[...]

** I'll keep that in mind - now where do you get 4 x 7868s in new
condition ??

F.e. at :
http://www.tubeworld.com/tubes.html

Have a look at the electrical equivalent 6GM5 too,
a beam power type, not a true penthode like 7868.
It's not pin compatible but more wallet compatible :-)

Trevor Wilson wrote:

"Phil Allison" wrote in message
...
Hi all,

Can anyone tell me the tube line up in the Luxman SQ 65 integrated hi-fi
mp - the model dates from the mid 1960s.


**7868 X 4 outputs.
6DT8 X 3
12AX7 X 2
6AU6 X 2

The tube types are stamped into the chassis. Clean the dust off, you'll find
the numbers.

I have one with a smoked PWR TX. Output TXs are fine.

--
Trevor Wilson
www.rageaudio.com.au

About 6 years ago I rewired a very tired Luxman amp with 4 x 7868.
It may have been an SQ65, I can't remember. It took a week to restore.

The owner didn't want to pay the $75 being asked for NOS replacement 7868s,
and settled for some EL34 I had at a much lower price.
Trouble was the case wasn't tall enough to fit the new tubes, and determined
owner
said make whatever alterations were necessary to get it functional, so
I sawed the top half of the case off, and fitted a taller new top with
perforated sheeting.

It finished up a nice sounding Turnuxman.

There was some 5% CFB from the OPT a la Quad II, which had a more useful 10%,
and I think they used CFB for gimmick and sales reasons.
(Musical Reference also used 5% CFB in their 36 watt channels using only 2 x
EL84).

The 7868 is suited for lower range bias current and class AB operation,
an EL34 runs well in any circuit using it, and gives similar power.
The use of 6550 would be over the top, since the PS couldn't reliably
supply a higher idle current, which those trying 6550 would be tempted to try.
Another good replacement would be the 6CM5/EL36,
which probably would work best if triode wired, although alterations to
biasing and driver tube have to be considered carefully.

The 7868 is smaller than a 6V6 but has large *nine* pin sockets, which all need
replacing if going to a more sensible
octal based tube.

The Luxman OPTs were not too bad, and anyone with a pair could build a nice amp
using them
plus a decent power tranny.

I had a Luxman stereo tube amp which a shop donated to me with one OPT missing,
and
it had 50C5 tubes a little bigger than the 7868,
which used 50v for filaments, which were seriesed off the mains.
It had bloomin 12 pin sockets, like on the back of TV picture tubes.
Such inovation was all BS imho.
I don't think the japanese were ever really accepting of the style of large
american
or english amps, and preferred their own style for their tiny cramped houses
with thin walls where
high amp power wasn't needed. I am almost certain japanese women prefered amps
and sound gear to be heard but not seen.
My japanese friend here who knows a lot of places in Japan where an OPT might
have been found
could not source one.
It ran off 110v, and I have since stripped it down
to spares, and removed all the very nice PT laminations for use in some future
tranny.

Buying 7868 replacements at a high price probably is the least labour intensive
repair one could
carry out.

Patrick Turner.

Patrick Turner said:

It finished up a nice sounding Turnuxman.

LOL!!!!!!

--
Sander deWaal
Vacuum Audio Consultancy

About 6 years ago I rewired a very tired Luxman amp with 4 x 7868.
It may have been an SQ65, I can't remember. It took a week to restore.

The owner didn't want to pay the $75 being asked for NOS replacement 7868s,
and settled for some EL34 I had at a much lower price.
Trouble was the case wasn't tall enough to fit the new tubes, and determined
owner
said make whatever alterations were necessary to get it functional, so
I sawed the top half of the case off, and fitted a taller new top with
perforated sheeting.


The cost of a week of your time would dwarf the cost of whatever tubes
(except maybe WE's).
Or was it not a commercial restore?






Buying 7868 replacements at a high price probably is the least labour intensive
repair one could
carry out.



That's what I would think as well.

Just in case nobody has thought about it

7868 is identical to 7591A, but the 7591A has an octal base. 4 Octal sockets, and 4
Sovtek 7591A's may be your best low cost option, and will make it easy for the owner
to replace tubes in the future

Max

Sander deWaal wrote:

Patrick Turner said:

It finished up a nice sounding Turnuxman.

LOL!!!!!!

Or otherwise could have been a Luxner.

I've built a few Dyners, Turnacos, Leakner, Turneaks,
Quadners or Turquads in my time....
Even one Turnnard or Lenner.
And the ocasional Radioner or Turniola radio.
My Trioner or Turnio AM/FM set sounds well.
A client's Kenwood reciever became a Turnerwood,
since Ken had nothing to do with it anymore.

So I guess when you tweak the bejesus out of some old set
it may become a Waalaco, or Leakwaal, ( which has an unfortunate
secondary meaning )....

Patner Turrick.




--
Sander deWaal
Vacuum Audio Consultancy

Robert Casey wrote:





About 6 years ago I rewired a very tired Luxman amp with 4 x 7868.
It may have been an SQ65, I can't remember. It took a week to restore.

The owner didn't want to pay the $75 being asked for NOS replacement 7868s,
and settled for some EL34 I had at a much lower price.
Trouble was the case wasn't tall enough to fit the new tubes, and determined
owner
said make whatever alterations were necessary to get it functional, so
I sawed the top half of the case off, and fitted a taller new top with
perforated sheeting.


The cost of a week of your time would dwarf the cost of whatever tubes
(except maybe WE's).
Or was it not a commercial restore?

The cost was commercial, and to be nice I charged the guy 1963 wage rates.
I am a little more costly now to employ.
Its not only hard to make a quid building new gear, but also
hard to make anything when a total rebuild is done, because ppl have this silly
idea its just a hobby for me.
Nearly all craftsmen and artisans artists, can never make average weekly earnings.
Ppl think a hand crafted item should cost the same as the mass produced asian
import.
And they think any repair should cost less than what they paid for the item, which
may
have been almost nothing at a second hand dealer.

Fortunately, enough ppl respect all the effort one puts in.

Patrick Turner.










Buying 7868 replacements at a high price probably is the least labour intensive
repair one could
carry out.



That's what I would think as well.

MaxH wrote:

Just in case nobody has thought about it

7868 is identical to 7591A, but the 7591A has an octal base. 4 Octal sockets, and 4
Sovtek 7591A's may be your best low cost option, and will make it easy for the owner
to replace tubes in the future

Well that's something I never knew.
I'll keep that in mind.
What about the tube size?

Patrick Turner.



Max

Patrick Turner wrote:

MaxH wrote:

Just in case nobody has thought about it

7868 is identical to 7591A, but the 7591A has an octal base. 4 Octal sockets, and 4
Sovtek 7591A's may be your best low cost option, and will make it easy for the owner
to replace tubes in the future

Well that's something I never knew.
I'll keep that in mind.
What about the tube size?


The tube size is slightly larger (like a Sovtek 5881)... you could possibly enlarge the
holes, and recess the new sockets to gain some clearance, or if it's an open chassis amp
then no big deal. This would be easier than EL34's, as it requires no circuit
modification. If you do want to modify the circuit, but not the enclossure, the natural to
my mind is either Tung Sol 5881's or Sylvania 6L6WGB's. I haven't kept up on current
pricing on either of those options though, so it may not be any savings over 7868's.



Patrick Turner.



Max

Patrick Turner said:

So I guess when you tweak the bejesus out of some old set
it may become a Waalaco, or Leakwaal, ( which has an unfortunate
secondary meaning )....

Umm.......my modifications are and will be nameless ;-)

OTOH, I have a Cary at hand tight now.........shall I call it Wacary?

--
Sander deWaal
Vacuum Audio Consultancy