Iain Churches wrote:



There is one currently on e-Bay for GBP 1954.29



** Stale news.

TW mentioned it and I answered him.

Pays to read a thread before posting.

Iain Churches wrote:

-------------------------



It was clearly a quality product.



** But not a long lasting one.

Using weird 9 pin output valves is major drawback.


..... Phil

In article , Phil
Allison scribeth thus

** Hi,


this week a old customer donated his long out of use Luxman SQ65 integrated,
valve amp to me saying maybe I could fix it, sell it and make some money.

What an optimist, the amp is over 50 years old and still has most of the
original valves fitted - plus 3 missing. Some of the valves are oddball, like
6DT8s phase splitters and 7868 noval outputs - neither type available in
Australia.

The SQ65 is sort of famous for having both " motional feedback " controls and
using cathode feedback in the output stage (a la Quad II ) so I persisted.


Put it on the bench for basic tests, gradually winding it up with a Variac and
immediately found the main electros had depolarised.
[*]

Next I found the bridge
rectifier was only working half wave and even then with a huge voltage drop.

So I fitted a new bridge across the old one and after half an hour reached full
AC supply without smoke so I let it soak for an hour or so.

My ESR meter informed that the main (dual can) filter electro was worn out -
various others seemed still functional.

Then I checked the two output transformers with an ohmmeter and got strange
readings from the first but the expected ones from the other. The first tranny
proved to have an open primary winding - damn.

So fixing the thing for profit was completely out of the question.

I extracted the good output tranny and bench tested it using 240VAC across half
the primary and a 16ohm dummy load on the secondary. Ran it for several hours
until it got warm and saw no problems. At a pinch it might do as a replacement
in my a Quad II workshop amp one day.

Based on Googling, I discovered that if fixed and working well an SQ65 has
little value and there is simply no demand.

It will be going out on the next council clean up day.




.... Phil



* Any gear older then say 10 - 15 years electros are very big contenders
for changing especially in output couplers and power supply rails like
the old Quad 303, are there any UN-upgraded ones left now;?.

Recapped a HP 339A distortion test set here. Was a bit "quieter" on
residuals after that, same with an elderly Marconi 2035 mod meter and
some other now getting on but otherwise OK equipment.

Pity that you can't get the knobs for the 339A anymore, real pain making
up replacements they are..

--
Tony Sayer

tony sayer wrote:

------------------------


** Hi,


this week a old customer donated his long out of use Luxman SQ65 integrated,
valve amp to me saying maybe I could fix it, sell it and make some money.

What an optimist, the amp is over 50 years old and still has most of the
original valves fitted - plus 3 missing. Some of the valves are oddball, like
6DT8s phase splitters and 7868 noval outputs - neither type available in
Australia.

The SQ65 is sort of famous for having both " motional feedback " controls and
using cathode feedback in the output stage (a la Quad II ) so I persisted.


Put it on the bench for basic tests, gradually winding it up with a Variac and
immediately found the main electros had depolarised.

[*]

Next I found the bridge
rectifier was only working half wave and even then with a huge voltage drop.

So I fitted a new bridge across the old one and after half an hour reached full
AC supply without smoke so I let it soak for an hour or so.

My ESR meter informed that the main (dual can) filter electro was worn out -
various others seemed still functional.

Then I checked the two output transformers with an ohmmeter and got strange
readings from the first but the expected ones from the other. The first tranny
proved to have an open primary winding - damn.

So fixing the thing for profit was completely out of the question.

I extracted the good output tranny and bench tested it using 240VAC across half
the primary and a 16ohm dummy load on the secondary. Ran it for several hours
until it got warm and saw no problems. At a pinch it might do as a replacement
in my a Quad II workshop amp one day.

Based on Googling, I discovered that if fixed and working well an SQ65 has
little value and there is simply no demand.

It will be going out on the next council clean up day.




.... Phil



* Any gear older then say 10 - 15 years electros are very big contenders
for changing especially in output couplers and power supply rails



** Calender age is not the main factor, hours of usage and internal temp is.

I see electros regularly that are 40 or 50 years old and PERFECT.

Even that 50yo Lux SQ65 only had ONE clearly defective electro.





...... Phil

In article ,
tony sayer wrote:
* Any gear older then say 10 - 15 years electros are very big contenders
for changing especially in output couplers and power supply rails like
the old Quad 303, are there any UN-upgraded ones left now;?.

Yes. My 303 is 1970, and never been opened up. Not in regular use now -
but did rig it up the other day for a party elsewhere. Sounded as normal.
It was in daily use up until about 5 years ago.

--
*What am I? Flypaper for freaks!?

Dave Plowman London SW
To e-mail, change noise into sound.

In article , Phil
Allison scribeth thus
tony sayer wrote:

------------------------


** Hi,


this week a old customer donated his long out of use Luxman SQ65 integrated,
valve amp to me saying maybe I could fix it, sell it and make some money.

What an optimist, the amp is over 50 years old and still has most of the
original valves fitted - plus 3 missing. Some of the valves are oddball, like
6DT8s phase splitters and 7868 noval outputs - neither type available in
Australia.

The SQ65 is sort of famous for having both " motional feedback " controls and
using cathode feedback in the output stage (a la Quad II ) so I persisted.


Put it on the bench for basic tests, gradually winding it up with a Variac
and
immediately found the main electros had depolarised.

[*]

Next I found the bridge
rectifier was only working half wave and even then with a huge voltage drop.

So I fitted a new bridge across the old one and after half an hour reached
full
AC supply without smoke so I let it soak for an hour or so.

My ESR meter informed that the main (dual can) filter electro was worn out -
various others seemed still functional.

Then I checked the two output transformers with an ohmmeter and got strange
readings from the first but the expected ones from the other. The first
tranny
proved to have an open primary winding - damn.

So fixing the thing for profit was completely out of the question.

I extracted the good output tranny and bench tested it using 240VAC across
half
the primary and a 16ohm dummy load on the secondary. Ran it for several hours
until it got warm and saw no problems. At a pinch it might do as a
replacement
in my a Quad II workshop amp one day.

Based on Googling, I discovered that if fixed and working well an SQ65 has
little value and there is simply no demand.

It will be going out on the next council clean up day.




.... Phil



* Any gear older then say 10 - 15 years electros are very big contenders
for changing especially in output couplers and power supply rails



** Calender age is not the main factor, hours of usage and internal temp is.

Well some gear gets more use than others!


I see electros regularly that are 40 or 50 years old and PERFECT.

Anyone actually got a 303 with the originals therein?...


Even that 50yo Lux SQ65 only had ONE clearly defective electro.





..... Phil




--
Tony Sayer

In article , Dave Plowman (News)
scribeth thus
In article ,
tony sayer wrote:
* Any gear older then say 10 - 15 years electros are very big contenders
for changing especially in output couplers and power supply rails like
the old Quad 303, are there any UN-upgraded ones left now;?.

Yes. My 303 is 1970, and never been opened up. Not in regular use now -
but did rig it up the other day for a party elsewhere. Sounded as normal.
It was in daily use up until about 5 years ago.


Still worth some new caps you can get 4700 uF in where the 2000 uF's
used to go..

Bet PW would have used them had they been around


http://www.net-audio.co.uk/quad303caps.html
--
Tony Sayer

tony sayer wrote:

----------------------



** Calender age is not the main factor, hours of usage and internal temp is.

Well some gear gets more use than others!


I see electros regularly that are 40 or 50 years old and PERFECT.

Anyone actually got a 303 with the originals therein?...


** Plowman says HE does.

Did you miss that?


..... Phil

tony sayer wrote:

-------------------

Still worth some new caps you can get 4700 uF in where the 2000 uF's
used to go..

Bet PW would have used them had they been around



** Maybe not.

If you are using Quad ESL57s, the output cap can interact with the transformer and create series resonance - hence a very low impedance at a sub sonic frequency. Bad news when using a TT.

One reason why the 303 has a HPF built in.

..... Phil


...... Phil

In article ,
tony sayer wrote:
In article , Dave Plowman (News)
scribeth thus
In article ,
tony sayer wrote:
* Any gear older then say 10 - 15 years electros are very big
contenders for changing especially in output couplers and power
supply rails like the old Quad 303, are there any UN-upgraded ones
left now;?.

Yes. My 303 is 1970, and never been opened up. Not in regular use now -
but did rig it up the other day for a party elsewhere. Sounded as
normal. It was in daily use up until about 5 years ago.


Still worth some new caps you can get 4700 uF in where the 2000 uF's
used to go..

Why would I replace caps on an amp that still sounds OK? No audible hum.

Bet PW would have used them had they been around


http://www.net-audio.co.uk/quad303caps.html

--
*Why is the man who invests all your money called a broker?

Dave Plowman London SW
To e-mail, change noise into sound.