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Readily Visible Readily Visible is offline
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Default Vintage Pioneer SX-838 receiver- I MISDIAGNOSED !

I am deaf in one ear and cannot locate the direction from which a sound
originates so I was relying on the balance knob and not the speakers, to
tell me that the left channel was dropping out, even when I switched the
preamp right and left outputs into the power amp inputs. That was an
entirely erroneous episode of troubleshooting. The balance knob
continued to to tell me that the left channel was dropping out, but in
reality the output at the speaker jacks was switching from the left to
the right channel. I only discovered this when measuring the AC voltage
at various points in the power amp wiring. I was puzzled at the readings
I was getting and went to the speaker jacks where the speaker wires were
connected.

Long story short, the dead channel at the speaker jacks switched from
left to right when I switched the preamp outputs going to the power amp
inputs.

I have to put this aside for a minute and re-read all the relies I have
gotten dealing with possible cause on the preamp side of the unit.

My apologies to all who followed me down the wrong path with this unit.

Time to start fresh... mañana.

Jack
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William Sommerwerck William Sommerwerck is offline
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Default Vintage Pioneer SX-838 receiver- I MISDIAGNOSED !

"Readily Visible" wrote in message
...

I am deaf in one ear and cannot locate the direction
from which a sound originates...


Why am I reminded of André De Toth, the director of "House of Wax", who was
blind in one eye?


diagnostic material snipped

Long story short, the dead channel at the speaker jacks switched from
left to right when I switched the preamp outputs going to the power amp
inputs.
I have to put this aside for a minute and re-read all the relies I have
gotten dealing with possible cause on the preamp side of the unit.
My apologies to all who followed me down the wrong path with this unit.
Time to start fresh... mañana.



ARRRGGGHHH!

Lemme tell you a story...

Way back in 1980, when I was living in PA, an acquaintance asked me to help
a friend diagnose a problem with his Dayton-Wright preamp. I don't remember
what the problem was, but there _was_ an obvious likely cause.

"Did you check thus-and-such?"
"Yes."
"You're absolutely certain?"
"Yes."
"You're really, really sure?"
"Yes."
"Okay, bring it over and we'll have a look."

I hooked the preamp to my Lux Laboratory Reference Series components, and
when I moved the input selector switch, both output stages of the power amp
were blown out. "****ed" is hardly the adjective.

Naturally, I sent the guy packing -- and the power amp to Lux for repair.
(That's called "zeugma" -- one verb yoked to two subjects.) I later learned
that he had not properly checked out the unit, and that my original
suspicion as to the nature of the problem was correct.

There are several points to be made. One is that it's not a good idea to
help people who you don't know, especially when you're not being paid for
it. Another is that you should thoroughly check someone else's equipment
before you put it in your system. * (DC offsets and output oscillations are
good things to look for.)

But the most-important point is that you can't trust other people to
correctly describe what's wrong with their equipment. Heck, you can't even
trust yourself! How many times have you gotten thoroughly confused as you
work your way through the diagnosis?

Nevertheless, I hope Readily Visible's SX-838 bursts into flames while he's
asleep, burning his house to the ground and destroying all his possessions.
And his little dog, too.

* In this case, I wouldn't have caught the problem. It turned out that the
Dayton-Wright preamp used switches that were very good at generating RF when
opened or closed. The RF caused the triple-diffused output devices in the
Lux 5M50 to melt from tertiary breakdown, a known problem with this power
amp. (Ironically, Mike Wright was aware of the RF problem with the preamp,
and had added holes to the PC board for suppression caps. Unfortunately, the
holes were not populated.) This was not the first nor the last time this
happened; the next time was my own stupid fault.


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Default Vintage Pioneer SX-838 receiver- I MISDIAGNOSED !

William Sommerwerck wrote:
"Readily Visible" wrote in message
...

I am deaf in one ear and cannot locate the direction
from which a sound originates...


Why am I reminded of André De Toth, the director of "House of Wax", who was
blind in one eye?


diagnostic material snipped

Long story short, the dead channel at the speaker jacks switched from
left to right when I switched the preamp outputs going to the power amp
inputs.
I have to put this aside for a minute and re-read all the relies I have
gotten dealing with possible cause on the preamp side of the unit.
My apologies to all who followed me down the wrong path with this unit.
Time to start fresh... mañana.



ARRRGGGHHH!

Lemme tell you a story...

Way back in 1980, when I was living in PA, an acquaintance asked me to help
a friend diagnose a problem with his Dayton-Wright preamp. I don't remember
what the problem was, but there _was_ an obvious likely cause.

"Did you check thus-and-such?"
"Yes."
"You're absolutely certain?"
"Yes."
"You're really, really sure?"
"Yes."
"Okay, bring it over and we'll have a look."

I hooked the preamp to my Lux Laboratory Reference Series components, and
when I moved the input selector switch, both output stages of the power amp
were blown out. "****ed" is hardly the adjective.

Naturally, I sent the guy packing -- and the power amp to Lux for repair.

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William Sommerwerck William Sommerwerck is offline
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Default Vintage Pioneer SX-838 receiver- I MISDIAGNOSED !

Big difference between me and your friend, Einstein... no one that I was
asking advice from was stupid enough to hook my gear up to their gear.


It's not enough that someone (me) pokes public fun at his foolishness. You
have to rub it in by calling him stupid, as well. For a person who
(apparently) doesn't have a lot of experience servicing equipment, you not
only lack a sense of humor, but you're quick to snipe at someone who
probably knows a lot more than you do, you rude louse.


Oh, and by the way, I fixed my gear. It is playing perfectly as I type.


God knows, it took long enough. The next time you want help, don't expect me
to be offering it.


Maybe some day you will learn to fix your own gear without sending it out.


Unless you're well past 40 (or so) I was servicing electronic equipment
before you were born. And I worked as a paid technician for a short time.
The store owner (Jack Rubinson of Chestnut Hill Audio in Philadelphia)
complimented me for never having callbacks. I made sure stuff was properly
fixed before it went out.

By the way, the next time the output transistors in the Lux blew, I replaced
and rebiased them myself. It was no big deal. But the amp is still working,
over 25 years later.


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Default Vintage Pioneer SX-838 receiver- I MISDIAGNOSED !

William Sommerwerck wrote:
Big difference between me and your friend, Einstein... no one that I was
asking advice from was stupid enough to hook my gear up to their gear.


It's not enough that someone (me) pokes public fun at his foolishness. You
have to rub it in by calling him stupid, as well.




Your friend wasn't the stupid one.

He didn't fry his gear plugging someone else's gear into it.



For a person who
(apparently) doesn't have a lot of experience servicing equipment, you not
only lack a sense of humor, but you're quick to snipe at someone who
probably knows a lot more than you do, you rude louse.


Oh, and by the way, I fixed my gear. It is playing perfectly as I type.


God knows, it took long enough. The next time you want help, don't expect me
to be offering it.


Maybe some day you will learn to fix your own gear without sending it out.


Unless you're well past 40 (or so) I was servicing electronic equipment
before you were born. And I worked as a paid technician for a short time.
The store owner (Jack Rubinson of Chestnut Hill Audio in Philadelphia)
complimented me for never having callbacks. I made sure stuff was properly
fixed before it went out.

By the way, the next time the output transistors in the Lux blew, I replaced
and rebiased them myself. It was no big deal. But the amp is still working,
over 25 years later.




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Default Vintage Pioneer SX-838 receiver- I MISDIAGNOSED !

What is Islam?-1

Please forgive me for any disturbance, but I have an important subject
to address to you regarding FAITH, and I Don’t intend to overload your
email with unnecessary messages…

What is Islam?-1


ABOUT THE WORDS "ISLAM" AND "MUSLIM"

The name of this religion is Islam, the root of which is S-L-M, which
means peace. The word "Salam," derived from the same root, may also
mean greeting one another with peace.

One of the beautiful names of God is that He is Peace. But Islam means
more than that: it means submission to the One God, and it means
living in peace with the Creator — peace within one’s self, peace
with other people, and peace with the environment.

Thus, Islam is a total system of living. A Muslim is supposed to live
in peace and harmony with all these segments. It follows that a Muslim
is any person, anywhere in the world, whose obedience, allegiance, and
loyalty are to God, the Lord of the Universe.

IS "MUSLIM" THE SAME AS ARAB?

The followers of Islam are called Muslims. Muslims are not to be
confused with Arabs.

Muslims may be Arabs, Turks, Persians, Indians, Pakistanis,
Malaysians, Indonesians, Europeans, Africans, Americans, Chinese, or
other nationalities.

An Arab could be a Muslim, a Christian, a Jew or an atheist. Any
person who adopts the Arabic language is called an Arab.

The language of the Qur’an (the Holy Book of Islam) is Arabic. Muslims
all over the world try to learn or improve their Arabic, so that they
may be able to read the Qur’an and understand its meaning. They pray
in the language of the Qur’an, Arabic. Islamic supplications to God
could be (and are) delivered in any language.

There are one billion Muslims in the world; there are about 200
million Arabs. Among those two hundred million Arabs, approximately
ten percent are not Muslims. Thus Arab Muslims constitute only about
twenty percent of the Muslim population of the world.
-

ALLAH THE ONE AND THE ONLY GOD

"Allah" was the Arabic word for God long before the birth of Muhammad,
peace be upon him.

Muslims believe that Allah is the name of the One and Only God. He is
the Creator of all human beings. He is the God for the Christians, the
Jews, the Muslims, the Buddhists, the Hindus, the atheists, and all
others. Muslims worship God, whose name is Allah. They put their trust
in Him and they seek His help and His guidance.

MUHAMMAD

Muhammad was chosen by God to deliver His Message of Peace, namely
Islam. He was born in 570 C.E. (Common Era) in Makkah, Arabia. He was
entrusted with the Message of Islam when he was at the age of forty
years. The revelation that he received is called the Qur’an, while the
message is called Islam.

Muhammad is the very last Prophet of God to mankind. He is the final
Messenger of God. His message was and is still to the Christians, the
Jews and the rest of mankind. He was sent to those religious people to
inform them about the true mission of Jesus, Moses, Jacob, Isaac, and
Abraham.

Muhammad is considered to be the summation and the culmination of all
the prophets and messengers that came before him. He purified the
previous messages from adulteration and completed the Message of God
for all humanity. He was entrusted with the power of explaining,
interpreting and living the teaching of the Qur’an.

ISLAM AND NON-MUSLIMS

Muslims are required to respect all those who are faithful and God
conscious people, namely those who received messages. Christians and
Jews are called People of the Book. Muslims are asked to call upon the
People of the Book for common terms, namely, to worship One God, and
to work together for the solutions of the many problems in the
society.

Christians and Jews lived peacefully with Muslims throughout centuries
in the Middle East and other Asian and African countries. The second
Caliph, Umar, chose not to pray in the church in Jerusalem, so as not
to give later Muslims an excuse to take it over. Christians entrusted
the Muslims, and as such the key of the Church in Jerusalem is still
in the hands of the Muslims.

When Jews fled from Spain during the Inquisition, they were welcomed
by the Muslims. They settled in the heart of the Islamic Caliphate.
They enjoyed positions of power and authority. Throughout the Muslim
world, churches, synagogues and missionary schools were built within
the Muslim neighborhoods. These places were protected by Muslims
during bad times and good, and have continued to receive this
protection during the contemporary crises in the Middle East


Thank You

————————–

For more information about Islam

http://english.islamway.com/

http://www.islamhouse.com/

http://www.discoverislam.com/

http://www.islambasics.com/index.php

http://english.islamway.com/

http://www.islamtoday.net/english/

http://www.islamweb.net/ver2/MainPage/indexe.php

http://www.sultan.org/

http://www.islamonline.net/

Contact Us At



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Arfa Daily Arfa Daily is offline
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"Readily Visible" wrote in message
...
William Sommerwerck wrote:
Big difference between me and your friend, Einstein... no one that I was
asking advice from was stupid enough to hook my gear up to their gear.


It's not enough that someone (me) pokes public fun at his foolishness.
You
have to rub it in by calling him stupid, as well.




Your friend wasn't the stupid one.

He didn't fry his gear plugging someone else's gear into it.



Considering all the hoops that every one of the good folk on here have gone
through in order to try to help you, I would suggest that you stop pursuing
this line of posting right away, otherwise, I can see it descending into a
name-calling session that you really wouldn't want to be on the end of.
William has been mild in his chastisement of you, compared to how some may
be, if you wake them ...

So, after all that, you say that you have now fixed it. Perhaps out of
courtesy to the group, and all those professional people and gifted
hobbyists who took the time and trouble to try to point you in the right
direction, you would be good enough to share with us what the problem was ?

Arfa


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Default Vintage Pioneer SX-838 receiver- I MISDIAGNOSED !

"William Sommerwerck" wrote in
message

* In this case, I wouldn't have caught the problem. It
turned out that the Dayton-Wright preamp used switches
that were very good at generating RF when opened or
closed. The RF caused the triple-diffused output devices
in the Lux 5M50 to melt from tertiary breakdown, a known
problem with this power amp. (Ironically, Mike Wright was
aware of the RF problem with the preamp, and had added
holes to the PC board for suppression caps.
Unfortunately, the holes were not populated.) This was
not the first nor the last time this happened; the next
time was my own stupid fault.


The real problem is that both the DW preamp and the Lux power amp were just
more examples of poorly-designed high end junk.

The world is full of fine-sounding preamps that don't create RF-rich
transients when you operate their controls. Many of them create no audible
transients at all! The world is similarly full of fine-sounding power amps
that don't melt down every time you drive them with a few transients, or
even a lot of transients.

It would be interesting to know what fraction of the total production of
Dayton-Wright audio products are still in service. It's my recollection
that DW briefly rose to fame on the strength of an interesting idea with a
lot of potential - sealing electrostatic speaker elements in thin plastic
envelopes full of an insulating gas. Unfortunately, they were also the
reactive loads from #&!! and could and did fail frequently in actual use.

As far as the fail-o-matic Lux power amp went, Lux had been around for a
long time even way back then. They should have known better. Apparently
their transition from tubes to solid state was not smooth. Lots of people
built very durable power amps with triple-diffused output devices. No doubt
Lux figured it out, or simply went out of business due to their technical
incompetence.


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"Arny Krueger" wrote in message
...
"William Sommerwerck" wrote in
message


* In this case, I wouldn't have caught the problem. It
turned out that the Dayton-Wright preamp used switches
that were very good at generating RF when opened or
closed. The RF caused the triple-diffused output devices
in the Lux 5M50 to melt from tertiary breakdown, a known
problem with this power amp. (Ironically, Mike Wright was
aware of the RF problem with the preamp, and had added
holes to the PC board for suppression caps.
Unfortunately, the holes were not populated.) This was
not the first nor the last time this happened; the next
time was my own stupid fault.


The real problem is that both the DW preamp and the Lux power
amp were just more examples of poorly-designed high end junk.


For their time, none of the Laboratory Reference Series products -- except
the 5T50 tuner -- was particularly expensive. * They weren't cheap, but they
weren't Mark Levinson, either.

Junk is in the eye of the beholder. All my LRS stuff continues to work,
though it's more than 30 years old.

* According to the guy who fouded Kinergetics, the 5T50 was designed to
"sound like" the Marantz 10B. I don't know if it did or didn't, but several
reviewers felt that the 5T50 was the first digital tuner that "sounded
good", supposedly because Lux did a good job keeping the digital "junk" out
of the audio circuits. This ought to be a trivial engineering exercise, so
if the 5T50's sound was surperior, it was likely for another reason.


The world is full of fine-sounding preamps that don't create RF-rich
transients when you operate their controls. Many of them create no
audible transients at all! The world is similarly full of fine-sounding
power amps that don't melt down every time you drive them with a
few transients, or even a lot of transients.


I don't know why Willaim Watson Michael Dayton-Wright chose those particular
switches. If you want to damn him, damn him for not installing the caps.

As for the power amp... At the time it was designed, there was a lot of
arguing about slewing-induced distortion, TIM, and the like. (There were
tube power amps that suffered from these problems. Dig through your
early-80s JAES issues for an article about one.) The assumption was that,
the wider the open-loop bandwidth, the less likely TIM would be a problem.
So Lux used triple-diffused RF power transistors -- despite the common
knowledge that they could be blown by RF transients. That was the cause in
three cases where the output transistors blew -- not audio transisents.


It would be interesting to know what fraction of the total production of
Dayton-Wright audio products are still in service. It's my recollection
that DW briefly rose to fame on the strength of an interesting idea with
a lot of potential [sic!] - sealing electrostatic speaker elements in thin
plastic envelopes full of an insulating gas. Unfortunately, they were also
the reactive loads from #&!! and could and did fail frequently in actual

use.

The Dayton-Wright electrostatic speakers could, with a suitable amplifier
(such as Crown M-300) play at near-earsplitting levels in a large, dead
room, cleanly. I do not recollect the panels having a reputation for
failure, though I could be wrong. The use of SF6 as the dielectric gas
reduced arcing, which is the principal (thought not only) cause of panel
failure.

These speakers were among the hardest-to-drive loads, ever. There was a bass
impedance peak of around 100 ohms, while the impedance fell to less than 2
ohms in the upper midrange. If the amp couldn't pump the required current
(and some couldn't, even at moderate levels), you'd hear "current clipping".

One might equally ask "What fraction of the total production of Company X's
products are still in service"? The switches and electrolytic caps are the
quickest components to deteriorate. I have (and have had) stuff over 40
years old, and am amazed that it continues to work.


As far as the fail-o-matic Lux power amp went...


Arny, you have a good vocabulary, so why not use it well? "Fail-o-matic"
suggests self-destruction, which this amplifer was /not/ prone to. (I could
name another brand of amplifer which, in my experience, repeatedly
self-destructed for no obvious reason.) It was damaged when subjected to a
form of electrical abuse that Lux naively assumed would never occur. Lux
should have added low-pass RF filtering outside the feedback loop.


...Lux had been around for a long time even way back then. They should
have known better. Apparently their transition from tubes to solid state
was not smooth. Lots of people built very durable power amps with triple-
diffused output devices.


Who? My understanding was that designers generally refused to use these
devices, precisely because of the known problems.


No doubt Lux [never?] figured it out, or simply went out of
business due to their technical incompetence.


Lux is still in business (I think), though a shadow of its former self.


And before we go... I have to acknowledge Arny's real motivation in posting
this. He just loves kicking people who own not-cheap equipment with
less-than-perfect reliability. "If only you'd bought Grommes, you wouldn't
have had these problems."

http://www.grommesprecision.com/precisionelectronics




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"Readily Visible" wrote in message
...
William Sommerwerck wrote:


Big difference between me and your friend, Einstein... no one that I was
asking advice from was stupid enough to hook my gear up to their gear.

Oh, and by the way, I fixed my gear. It is playing perfectly as I type.

Maybe some day you will learn to fix your own gear without sending it out.


Given all the time that people have spent, at no charge to yourself, to help
you fix a problem which, honestly, you don't seem competent to diagnose and
repair yourself, I find it in incredibly poor taste to make the comments you
have. This group has a very talented and extremely experienced core group
of techs like William Sommerwick, Arfa Daily, Mark Zacharias and (the
resident cynic) Arny Krueger who have been nothing less than courteous and
polite in their unfunded efforts to help you. Then, after you wasted all of
their time by posting erroneous information, you have the GALL to insult
them? I'd suggest you review the facts and lose the attitude, ye cad.



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Bob Larter Bob Larter is offline
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Default Vintage Pioneer SX-838 receiver- I MISDIAGNOSED !

William Sommerwerck wrote:
Big difference between me and your friend, Einstein... no one that I was
asking advice from was stupid enough to hook my gear up to their gear.


It's not enough that someone (me) pokes public fun at his foolishness. You
have to rub it in by calling him stupid, as well. For a person who
(apparently) doesn't have a lot of experience servicing equipment, you not
only lack a sense of humor, but you're quick to snipe at someone who
probably knows a lot more than you do, you rude louse.


Yeah, that's incredibly rude. If you need advice from other people, have
a bit of humility or **** off. If you were *that* superior, you wouldn't
need to ask for help.


--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------
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Bob Larter Bob Larter is offline
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Default Vintage Pioneer SX-838 receiver- I MISDIAGNOSED !

Readily Visible wrote:
William Sommerwerck wrote:
Big difference between me and your friend, Einstein... no one that I was
asking advice from was stupid enough to hook my gear up to their gear.

It's not enough that someone (me) pokes public fun at his foolishness. You
have to rub it in by calling him stupid, as well.




Your friend wasn't the stupid one.

He didn't fry his gear plugging someone else's gear into it.


Jeez, for someone who can't even spot a dry joint or a grotty relay
contact without help, you sure have one hell of an attitude! I notice
that you didn't act like this *before* your amp was working again.

--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------
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David Nebenzahl David Nebenzahl is offline
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Default Vintage Pioneer SX-838 receiver- I MISDIAGNOSED !

On 6/1/2009 2:49 AM abo mahab spake thus:

What is Islam?-1

Please forgive me for any disturbance, but I have an important subject
to address to you regarding FAITH, and I Don’t intend to overload your
email with unnecessary messages…


You are NOT FORGIVEN. Keep your religious bull**** out of here.


--
Found--the gene that causes belief in genetic determinism
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William Sommerwerck William Sommerwerck is offline
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Default Vintage Pioneer SX-838 receiver- I MISDIAGNOSED !

Given all the time that people have spent, at no charge to yourself, to
help
you fix a problem which, honestly, you don't seem competent to diagnose

and
repair yourself, I find it in incredibly poor taste to make the comments

you
have. This group has a very talented and extremely experienced core group
of techs like William Sommerwick...


I appreciate the implicit support, but I am nowhere nearly as experienced as
others in this group.


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Dave Dave is offline
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Default Vintage Pioneer SX-838 receiver- I MISDIAGNOSED !


"William Sommerwerck" wrote in message
...
Given all the time that people have spent, at no charge to yourself, to

help
you fix a problem which, honestly, you don't seem competent to diagnose

and
repair yourself, I find it in incredibly poor taste to make the comments

you
have. This group has a very talented and extremely experienced core
group
of techs like William Sommerwick...


I appreciate the implicit support, but I am nowhere nearly as experienced
as
others in this group.


You've been posting a long time, you know what you're doing in there as well
as anyone near as I can tell...



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William Sommerwerck William Sommerwerck is offline
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Default Vintage Pioneer SX-838 receiver- I MISDIAGNOSED !

"Dave" wrote in message
news:VAUUl.30247$PH1.15299@edtnps82...
"William Sommerwerck" wrote in message
...


Given all the time that people have spent, at no charge to yourself, to
helpyou fix a problem which, honestly, you don't seem competent to
diagnose and repair yourself, I find it in incredibly poor taste to make
the comments you have. This group has a very talented and extremely
experienced core groupof techs like William Sommerwerck...


I appreciate the implicit support, but I am nowhere nearly as experienced
as others in this group.


You've been posting a long time, you know what you're doing in there
as well as anyone near as I can tell...


I have an excellent -- indeed, I'd say exceptional -- sense of how to go
about diagnosing problems. But I don't have the in-depth, day-to-day
experience Arfa, et al, have.

I used to service most of my own equipment, but consumer electronics have
become so complex and so fundamentally un-repairable that I rarely repair
anything. The last item I fixed was one of my electronic crossovers,
replacing an output drivers. (Believe it or not, John Curl helped me
diagnose the problem, by pointing out something I'd overlooked.)

One of the reasons I'm here is that I like to see what's going on in
electronic servicing, and get a better view of how the "new stuff" works.
You never know when it might come in handy.


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Dave Dave is offline
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Default Vintage Pioneer SX-838 receiver- I MISDIAGNOSED !


"William Sommerwerck" wrote in message
...
I have an excellent -- indeed, I'd say exceptional -- sense of how to go
about diagnosing problems. But I don't have the in-depth, day-to-day
experience Arfa, et al, have.

I used to service most of my own equipment, but consumer electronics have
become so complex and so fundamentally un-repairable that I rarely repair
anything. The last item I fixed was one of my electronic crossovers,
replacing an output drivers. (Believe it or not, John Curl helped me
diagnose the problem, by pointing out something I'd overlooked.)

One of the reasons I'm here is that I like to see what's going on in
electronic servicing, and get a better view of how the "new stuff" works.
You never know when it might come in handy.


I'm about the same as far as experience goes. Background in electrical
engineering (long long time ago), used to repair just anything, but have
never had the urge to move into SMD work, my eyes probably aren't good
enough anyways. Most of the repairs of newer TV's, multi-channel amps, etc.
seem to be board replacements, which holds no interest for me... I like the
troubleshooting process itself and get great pleasure from being able to
take a doorstop that cost somebody $1,000 long ago and turn it back into a
great amplifier or TV or washing machine or for the cost of a few caps and a
$1 regulator or $5 IC. My collection of TV's, stereo equipment, etc. was in
large part received for free in non-working condition, and I doubt I've got
$100 in any single piece. My wife calls me a packrat but doesn't complain
about my rates...

This group is a gold mine for experience, and it annoys me to no end when
people dare to complain about ABSOLUTELY FREE advice and assistance. Advice
gleaned here has helped me to repair items of which I initially had little
or no understanding.

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Bob Larter Bob Larter is offline
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Default Vintage Pioneer SX-838 receiver- I MISDIAGNOSED !

William Sommerwerck wrote:
Given all the time that people have spent, at no charge to yourself, to

help
you fix a problem which, honestly, you don't seem competent to diagnose

and
repair yourself, I find it in incredibly poor taste to make the comments

you
have. This group has a very talented and extremely experienced core group
of techs like William Sommerwick...


I appreciate the implicit support, but I am nowhere nearly as experienced as
others in this group.


We all have skills that nobody else here has. Between us, we cover a
pretty amazing amount of territory.

--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------
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Bob Larter Bob Larter is offline
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Default Vintage Pioneer SX-838 receiver- I MISDIAGNOSED !

Dave wrote:

"William Sommerwerck" wrote in message
...
I have an excellent -- indeed, I'd say exceptional -- sense of how to go
about diagnosing problems. But I don't have the in-depth, day-to-day
experience Arfa, et al, have.

I used to service most of my own equipment, but consumer electronics have
become so complex and so fundamentally un-repairable that I rarely repair
anything. The last item I fixed was one of my electronic crossovers,
replacing an output drivers. (Believe it or not, John Curl helped me
diagnose the problem, by pointing out something I'd overlooked.)

One of the reasons I'm here is that I like to see what's going on in
electronic servicing, and get a better view of how the "new stuff" works.
You never know when it might come in handy.


I'm about the same as far as experience goes. Background in electrical
engineering (long long time ago), used to repair just anything, but have
never had the urge to move into SMD work, my eyes probably aren't good
enough anyways. Most of the repairs of newer TV's, multi-channel amps,
etc. seem to be board replacements, which holds no interest for me... I
like the troubleshooting process itself and get great pleasure from
being able to take a doorstop that cost somebody $1,000 long ago and
turn it back into a great amplifier or TV or washing machine or for the
cost of a few caps and a $1 regulator or $5 IC. My collection of TV's,
stereo equipment, etc. was in large part received for free in
non-working condition, and I doubt I've got $100 in any single piece.
My wife calls me a packrat but doesn't complain about my rates...


I'm a bit of a noob here, but I racked up about 5 years as a service
tech for computers, faxes, laser printers & inkjet printers. Then
another few years as the national Technical Specialist (ie; the go-to
guy for the entire country) for laser faxes & photocopiers, then a few
years doing actual electronics design work, followed by about 5 years
running a service department for laptops, lasers, inkjets & PCs. Since
then (10 years?), I've worked in networking, security & general IT
consulting. I don't know that much about troubleshooting consumer goods
(other than what I've done for myself or friends), but I do know my
stuff in my areas.

This group is a gold mine for experience, and it annoys me to no end
when people dare to complain about ABSOLUTELY FREE advice and
assistance. Advice gleaned here has helped me to repair items of which
I initially had little or no understanding.


Ditto. The gang here helped me repair my Tek oscilloscope, & were about
as nice & helpful as you could possibly imagine. I can't think of
anywhere else I could go, & get that quality of expertise. And it was
FREE! What kind of moron would argue with that?

--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------
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Mr.T Mr.T is offline
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Posts: 2,108
Default Vintage Pioneer SX-838 receiver- I MISDIAGNOSED !


"William Sommerwerck" wrote in message
...
I don't know why Willaim Watson Michael Dayton-Wright chose those

particular
switches. If you want to damn him, damn him for not installing the caps.


Yep I would, don't you?

As for the power amp... At the time it was designed, there was a lot of
arguing about slewing-induced distortion, TIM, and the like. (There were
tube power amps that suffered from these problems. Dig through your
early-80s JAES issues for an article about one.) The assumption was that,
the wider the open-loop bandwidth, the less likely TIM would be a problem.
So Lux used triple-diffused RF power transistors -- despite the common
knowledge that they could be blown by RF transients. That was the cause in
three cases where the output transistors blew -- not audio transisents.


And how trivial to filter RF from a power amp input. Even cheap amps do it
successfully without affecting the audio range.

MrT.




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