Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems.

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  #11   Report Post  
Old May 20th 17, 02:00 AM posted to sci.electronics.repair
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Default Ping Trevor Wilson

On 20/05/2017 10:09 AM, wrote:
"**I did not say that ALL Luxman integrated amps used such a
system. Just

their low end ones. I know of no amplifier that employs pre/main
connectors that does not disable the the tone controls when it is
used as a power amp only. "

Seems to be a misunderstanding here. If the tone controls are in the
power amp feedback loop then they would not affect the pre out of
course. Whether this is desirable or not is up in the air. By
disabled when used as a power amp I assume you mean bypassed, because
regular pre outs are after the tone controls.


**There is no misunderstanding on my part. Any amplifier that uses tone
controls as part of the power amp section (and Luxman is the only
manufacturer IME to do so - And I have serviced pretty much every
Marantz product made since the late 1960s - I was Marantz service
manager in Australia for several years) will not have pre/main
connections fitted.


"**If you think an Acoustimess™ system can EVER sound good, then
you need

to get out a lot more. Bose Acoustimess™ are absolute crap. There is
a huge, deep and wide hole in the frequency response of the system,
centred around 200Hz, the woofer module (it cannot, EVER, be called
a subwoofer) "

No disagreement here, but this was in conjunction with another
system. Together they sounded good. It was a corner situated system.
The Bose sats were on top of the big speakers and the bass module was
way back in the corner.


**Not a snowball's chance in Hell that such a system would provide a
credible high fidelity result. Certainly, someone with a poorly educated
ear might think it sounds impressive. But good (ie: HI FI), not a chance.


Best thing Bose made was the wave radio, they don't sound all that
great but for their size the do pretty well. Convenient, the customer
doesn't have to hook anything up. The sound is adequate for quite a
few people.


**WAY too expensive. Sound was OK. Just. The best two products Bose ever
did was their 'sound bar' and their desk top computer sound system. Both
were easy to use, sounded good and were reasonably well built and
presented. Everything else is ****.


But when you get like 901s, who the **** brainiac got the idea to use
nine speakers and face eight of them away from the listener ? We
strive to have clear sound, to have loudspeakers that sound almost
like the best of headphones but on a larger scale. Some people like
Bose but I think he was a snake oil salesman.


**Of course. The entire premise was faulty to any sane thinking human
(ie: Non-Trump voters).


All this "ambiance", that is your room, you DON'T WANT THAT. You want
the ambiance in the recording. Not your room.

Another good thing Bose made were my Mother's speakers. Smaller than
a toaster but shake the floor. I can't even get a model number, they
were some kind of special order I bought from where I worked at the
time.

Other than that I don't have much use for Bose. In my buddy's system
they served well as tweeters.


**They don't even do a good job at that. The cone area is far too large
to enable decent sound quality without beaming.

People forget that Amar Bose was the wealthiest person in the audio
business. By a very considerable margin. He got that way, by building
stuff as cheap as possible and selling it for as much as possible and
ploughing huge amounts into promotion. People forget that when Bose
first introduced surround sound systems, Bose was too cheap to pay Dolby
Labs to use their ubiquitous systems and, instead, developed their own,
incompatible, ****ty sounding one.

We must NEVER make excuses for Bose. ****ty products, ****ty company.



--
Trevor Wilson
www.rageaudio.com.au

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Old May 20th 17, 06:36 AM posted to sci.electronics.repair
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Default Ping Trevor Wilson

Trevor Wilson wrote:

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


**I did not say that ALL Luxman integrated amps used such a system. Just
their low end ones.



** Luxman were always a prestige brand that did not make low end models.

Simple models like the SQ606 from the late 60s ( single supply, cap coupled) still had Baxandall feedback tone controls.

http://www.hifido.co.jp/photo/10/608/60845/h.jpg

Lux had another brand called L&G aimed at the mass market:

https://i.ebayimg.com/00/s/NzY4WDEwMjQ=/z/VVQAAOSwWTRW1b5q/$_86.JPG

They were kinda colourful, like Sonab.


..... Phil

  #13   Report Post  
Old May 20th 17, 06:53 AM posted to sci.electronics.repair
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Default Ping Trevor Wilson

On 20/05/2017 3:36 PM, Phil Allison wrote:
Trevor Wilson wrote:

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


**I did not say that ALL Luxman integrated amps used such a system.
Just their low end ones.



** Luxman were always a prestige brand that did not make low end
models.


**I can assure you that they most certainly did. Perhaps not quite as
low end as those Sansui atrocities, but models that were significantly
less costly to make than their good models. As an authorised service
agent for the importer, since 1980, I've seen them all, though Interdyn
no longer import Luxman.


Simple models like the SQ606 from the late 60s ( single supply, cap
coupled) still had Baxandall feedback tone controls.


**Here's one of their budget models that employed tone controls as part
of the power amp stage feedback line:

https://www.hifiengine.com/manual_li...an/l-205.shtml

Cheap. Lots of failures with this model and others in the same range.
Usually simple stuff, like failed zeners. Using 0.5 Watt zeners at their
limits is asking for trouble. The engineer should have been sacked.

Of course, not as bad as this rubbish:

https://www.hifiengine.com/manual_li...sui/a-40.shtml

Check out the output stage. You'll note two things:

* No current limiters
* Mild steel plates that hold the output devices onto the heat sink
(badly).

There's much more with this range. They were horrible things.


http://www.hifido.co.jp/photo/10/608/60845/h.jpg

Lux had another brand called L&G aimed at the mass market:

https://i.ebayimg.com/00/s/NzY4WDEwMjQ=/z/VVQAAOSwWTRW1b5q/$_86.JPG

They were kinda colourful, like Sonab.


**Yep. Make no mistake: Luxman, like every other Jap brand has built
cheap stuff, to capitalise on the reputation of their good stuff. Except
Accuphase. I can't recall ever seeing anything cheap and nasty from them.



--
Trevor Wilson
www.rageaudio.com.au
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Old May 20th 17, 10:19 AM posted to sci.electronics.repair
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Default Ping Trevor Wilson

Trevor Wilson wrote:

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




** Luxman were always a prestige brand that did not make low end
models.


**I can assure you that they most certainly did. Perhaps not quite as
low end as those Sansui atrocities, but models that were significantly
less costly to make than their good models. As an authorised service
agent for the importer, since 1980, I've seen them all, though Interdyn
no longer import Luxman.


Simple models like the SQ606 from the late 60s ( single supply, cap
coupled) still had Baxandall feedback tone controls.


**Here's one of their budget models that employed tone controls as part
of the power amp stage feedback line:

https://www.hifiengine.com/manual_li...an/l-205.shtml

Cheap. Lots of failures with this model and others in the same range.
Usually simple stuff, like failed zeners. Using 0.5 Watt zeners at their
limits is asking for trouble. The engineer should have been sacked.


** I've seen an L-205 on my bench, a couple of years back.

Not a bad little amp, I felt.

The oddball tone control thing is not important, specially if you set them flat .


Of course, not as bad as this rubbish:

https://www.hifiengine.com/manual_li...sui/a-40.shtml

Check out the output stage. You'll note two things:

* No current limiters
* Mild steel plates that hold the output devices onto the heat sink
(badly).



** Seen one of them too, a budget model for sure.

Still, used with ordinary care they work fine long enough to outlast the sort of peripherals generally found.



...... Phil

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Old May 20th 17, 09:54 PM posted to sci.electronics.repair
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Default Ping Trevor Wilson

On 20/05/2017 7:19 PM, Phil Allison wrote:
Trevor Wilson wrote:

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




** Luxman were always a prestige brand that did not make low end
models.


**I can assure you that they most certainly did. Perhaps not quite
as low end as those Sansui atrocities, but models that were
significantly less costly to make than their good models. As an
authorised service agent for the importer, since 1980, I've seen
them all, though Interdyn no longer import Luxman.


Simple models like the SQ606 from the late 60s ( single supply,
cap coupled) still had Baxandall feedback tone controls.


**Here's one of their budget models that employed tone controls as
part of the power amp stage feedback line:

https://www.hifiengine.com/manual_li...an/l-205.shtml

Cheap. Lots of failures with this model and others in the same
range. Usually simple stuff, like failed zeners. Using 0.5 Watt
zeners at their limits is asking for trouble. The engineer should
have been sacked.


** I've seen an L-205 on my bench, a couple of years back.

Not a bad little amp, I felt.

The oddball tone control thing is not important, specially if you set
them flat .


Of course, not as bad as this rubbish:

https://www.hifiengine.com/manual_li...sui/a-40.shtml

Check out the output stage. You'll note two things:

* No current limiters * Mild steel plates that hold the output
devices onto the heat sink (badly).



** Seen one of them too, a budget model for sure.

Still, used with ordinary care they work fine long enough to outlast
the sort of peripherals generally found.


**Back when I had my retail store, I sold Sansui, NAD, Marantz and a few
other brands. NAD walked out the door, being the flavour of the month.
Whilst a decent performer, particularly with difficult speakers, I felt
the mid range Sansui was a superior product. Better built, using better
quality components (the trimmer pots didn't fall apart and the knobs
didn't fly off the switches with the Sansui), the Sansui sounded better
with most speakers. The rep asked if I wanted to sell their cheaper
stuff (similar to the A-40). I asked for a sample for a week. I stripped
it down and checked out carefully. There were a number of potentially
problematical areas and I declined the offer to sell the range.

Sometime later, an acquaintance popped in to buy a stereo. I
demonstrated several system, including the Sansui (not the cheap stuff)
and he went away to think on it. I met up with him a few months later
and asked how his search was going. He ended up buying the cheap Sansui
from DME. I told him that there were no hard feelings and wished him
well. Another year passed and I ran across him again. I expressed my
condolences on the loss of his house. I asked him if they fire
authorities had tracked down the source of the fire that burned his
house down. "Yep." He said. "It was that bloody Sansui stereo. It caught
fire."

See, one of the issues that I identified with the Sansui, is that there
are combustible materials on each end (plastic end pieces) and a pressed
fibre board base-plate. That, combined with a power transformer, where
the thermal fuse connections are easily accessible from the outside of
the transformer, means that lazy techs simply short the thermal fuse
when it fails (which it did in 90% of that range of Sansui amps). I
suspect my old friend had picked up a repacked amp, that had failed. You
can work out the rest. Horrible quality products.


--
Trevor Wilson
www.rageaudio.com.au


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Old May 21st 17, 02:49 AM posted to sci.electronics.repair
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Default Ping Trevor Wilson

Trevor Wilson wrote:

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

"Yep." He said. "It was that bloody Sansui stereo. It caught
fire."

See, one of the issues that I identified with the Sansui, is that there
are combustible materials on each end (plastic end pieces) and a pressed
fibre board base-plate. That, combined with a power transformer, where
the thermal fuse connections are easily accessible from the outside of
the transformer, means that lazy techs simply short the thermal fuse
when it fails (which it did in 90% of that range of Sansui amps). I
suspect my old friend had picked up a repacked amp, that had failed. You
can work out the rest. Horrible quality products.



** The purpose of the thermal fuse inside the power tranny is to preserve the integrity of the Class 2 insulation. If that were bypassed and the tranny ever got hot enough to catch fire, there is a glass fuse that blows very quickly soon as turns begin to short out.

For the tranny to get seriously hot, the amp must be in use playing music loudly. This is not gonna be the case when no-one is home or all are asleep.

If the primary of the tranny failed due to voltage spikes on the AC supply, the
glass fuse would still prevent fire.

Maybe the Sansui amp was involved in the fire, rather than the cause of it.

I've see people sit candles on top of their stereos.



..... Phil


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Old May 21st 17, 03:27 AM posted to sci.electronics.repair
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Default Ping Trevor Wilson

On Saturday, May 20, 2017 at 9:49:42 PM UTC-4, Phil Allison wrote:


Maybe the Sansui amp was involved in the fire, rather than the cause of it.


That's what I was thinking, but who knows? Around here firefighters need college degrees plus a few more years of specific training to advance beyond a typical grunt riding on the back of a hook and ladder. Unless someone died in the fire it wouldn't surprise me if the investigator just blamed the stereo, called it a day and went for a pizza.

Anyway, I remember the Sansuis of the 80s that would blow outputs and burn all the way back to the speaker selector switch. I never saw one that exteriorized flame but if the owner left the stupid thing on to keep the cat from being bored, it might have shorted it's outputs. Still, it's hard to believe it made it outside the case.



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Old May 21st 17, 04:52 AM posted to sci.electronics.repair
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Default Ping Trevor Wilson

Trevor Wilson wrote:

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


**I can assure you that they most certainly did. Perhaps not quite as
low end as those Sansui atrocities, but models that were significantly
less costly to make than their good models. As an authorised service
agent for the importer, since 1980, I've seen them all, though Interdyn
no longer import Luxman.



** Did you deal with Gordon Hoskins at any stage?

I met him in the late 70s while doing service work for a hi-fi and TV shop in Woollarah.

Despite the store stocking various Interdyn items, he refused to supply any spares or info on Luxman etc.



.... Phil




.... Phil

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Old May 21st 17, 06:22 AM posted to sci.electronics.repair
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Default Ping Trevor Wilson

On 21/05/2017 1:52 PM, Phil Allison wrote:
Trevor Wilson wrote:

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


**I can assure you that they most certainly did. Perhaps not quite as
low end as those Sansui atrocities, but models that were significantly
less costly to make than their good models. As an authorised service
agent for the importer, since 1980, I've seen them all, though Interdyn
no longer import Luxman.



** Did you deal with Gordon Hoskins at any stage?


**Of course. I even did work for him for a few years. To his credit,
bills were always paid by the due date. I mostly dealt with Dianne down
there at Arncliff, I never bought Luxman spares from him. I went
straight to the importer - International Dynamics. Excellent company to
deal with. Always pay their bills on time.


I met him in the late 70s while doing service work for a hi-fi and TV shop in Woollarah.

Despite the store stocking various Interdyn items, he refused to supply any spares or info on Luxman etc.


**That's because he is a massive dickhead. Certainly be 1980 (and
probably a long time prior) Interdyn were the importers for Luxman.
Hoskins was their Sydney agent and pretty much sole retailer for a long
time.


--
Trevor Wilson
www.rageaudio.com.au
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Old May 21st 17, 06:52 AM posted to sci.electronics.repair
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Default Ping Trevor Wilson

Trevor Wilson wrote:

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



**I can assure you that they most certainly did. Perhaps not quite as
low end as those Sansui atrocities, but models that were significantly
less costly to make than their good models. As an authorised service
agent for the importer, since 1980, I've seen them all, though Interdyn
no longer import Luxman.



** Did you deal with Gordon Hoskins at any stage?



**Of course. I even did work for him for a few years. To his credit,
bills were always paid by the due date. I mostly dealt with Dianne down
there at Arncliff, I never bought Luxman spares from him.


** Think I dealt with her over the phone once, to get some Luxman amp BJTs.

She was polite, efficient and I got the *correct* parts in the mail the next day. So I rang her back to say how pleased I was.

I remember her being astonished that anyone bothered to do such a thing.




Despite the store stocking various Interdyn items, he refused to supply any spares or info on Luxman etc.



**That's because he is a massive dickhead.



** ROTFL !!


Certainly be 1980 (and
probably a long time prior) Interdyn were the importers for Luxman.
Hoskins was their Sydney agent and pretty much sole retailer for a long
time.


** After taking on Alpage and Celestion plus opening the "Quality Hi-Fi" store in York Street, he didn't get any better.

Gordon must have been a sleazy used-car salesman in a previous life....



...... Phil


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