Some customers...

[Mark Zacharias]

How is it a grown man cannot understand the concept of keeping two wires
separate?

Fixed a Yamaha RX-A2010 with a blown channel back in December.

Under warranty.

Big job.

Cautioned him on speaker hook-ups, gave him our hand-out sheet explaining
speaker connections,
which also contains explicit warnings about shorting wires etc.

Nevertheless he brought it back this week with the same channel blown again.

It was all I could do not to just go off on the guy. He admitted fooling
around with the wires while the unit was powered up, and that the wires had
crossed. Exactly the sort of thing I had "educated" him about.

Fucking idiot. Lucky for him Yamaha is covering it again, and we needed the
work anyway.

Shit for brains god damn idiot. I knew better that this when I was sixteen
fucking years old!

I'm reminded of Chevy Chase's rant in Christmas Vacation...


Mark Z.

[dansabr...@yahoo.com]

i'm surprised that Yamaha is covering this. Usually, customer caused failures are not covered. I recall having discussions with customers about similar types of repair requests. It seems that they think that anything that failes regardless of the cause is covered. Not the case. Physically broken parts are not usually covered. In one case, a Sony diskman (portable CD player) had the cover broken off. The owner actually thought that this would be covered under warranty. I questioned what manufaturing defect "caused" this problem and did not get an answer...

Dan

[N_Cook]

I have a customer who keeps breaking things, often fatally, because he
picks up the nearest wallwart, having mislaid the original one, because
it looks the same size black lump and the connector pushes in, so it
must be ok .

[Cursitor Doom]

On Fri, 25 Mar 2016 05:48:15 -0500, Mark Zacharias wrote:

> Cautioned him on speaker hook-ups, gave him our hand-out sheet
> explaining speaker connections,
> which also contains explicit warnings about shorting wires etc.

Hey, come on. 16 ohms, 8 ohms, zero ohms; it's all the same. ;->

[Chuck]

On Fri, 25 Mar 2016 05:48:15 -0500, "Mark Zacharias"

Back in the late 70s we repaired a compact stereo that used RCA jacks
for speaker outputs. The customer came back with the stereo claiming
there was no output. We hooked it up and it worked fine. I had him
bring in his speakers. He had wired both the plus and minus leads to
the center connector on both speaker plugs. I kept a straight face
but unfortunately one of my techs went off on him.

---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

[amdx]

On 3/25/2016 6:32 AM, dansabr...@yahoo.com wrote:
>
> i'm surprised that Yamaha is covering this. Usually, customer caused failures are not covered. I recall having discussions with customers about similar types of repair requests. It seems that they think that anything that failes regardless of the cause is covered. Not the case. Physically broken parts are not usually covered. In one case, a Sony diskman (portable CD player) had the cover broken off. The owner actually thought that this would be covered under warranty. I questioned what manufaturing defect "caused" this problem and did not get an answer...
>
> Dan
>

Back in the 70's my Pioneer SX-828's protection circuit did it's job
and saved my several repairs.
Mikek

[pf...@aol.com]

Once upon a time, there was movement to color-code and size-code these things... It never quite took.

Peter Wieck
Melrose Park, PA

[Ralph Mowery]

"Mark Zacharias" <mark_za...@sbcglobal.net> wrote in message
news:LH8Jy.77627$NL6....@fx22.iad...

> How is it a grown man cannot understand the concept of keeping two wires
> separate?
>

Reminds me of when I was working on the CB radios around 1973. Fellow
brought in one that had a diode inside that is connected across the 12 volt
power line that shorts and blowes the fuse when connected in reverse. I
asked him it he hooked it up backwards and he said probably as he moved it
from his truck to the car. About a week later he was back in with the same
problem. Repaired it, and a week later he was back again, but said it would
be the last time for me to repair it. I said "oh". And he said he bought
another radio so he could leave them and not have to swap back and forth.

[MJC]

In article <d53c2fdd-65ec-4489...@googlegroups.com>,
dansabr...@yahoo.com says...

>
> I questioned what manufaturing defect "caused" this problem and did
not get an answer...
>
> Dan

Portable devices do have to be robust to be fit for purpose...

Mike.

[Cydrome Leader]

the RCA speaker outputs were as silly as the preamp to amp shunts stuck
into the RCA jacks at the factory.

Anybody ever remove one of those? Was never able to pull out out with my
bare hands, didn't care enough to try with pliers.

[jurb...@gmail.com]

>"the RCA speaker outputs were as silly as the preamp to amp shunts >stuck
>into the RCA jacks at the factory. "

I would actually like to have a switch on the front panel of an amp to switch the pre out/main in loop rather than their jumpers. Too easy to lose.

And then my buddy got this Marantz, a really nice one, 2325. It has the type of jack where you plug something in and it breaks the connection. I'd much rather have a switch, even if it is on the back and many of them are.

Another thing I noticed about those shunts is ain't none of the MFs ever the same size. I have had a drawerfull of them and still had to make shunts out of 12 gauge wire because none of them fit.

[Jeff Liebermann]

On Fri, 25 Mar 2016 05:48:15 -0500, "Mark Zacharias"
<mark_za...@sbcglobal.net> wrote:

>Cautioned him on speaker hook-ups, gave him our hand-out sheet explaining
>speaker connections,
>which also contains explicit warnings about shorting wires etc.

Put a 0.5 ohm xx watt resistor in series with each speaker. Paint the
resistors with whatever concoction generates the most noxious smoke
possible[1]. Then he shorts the leads again, the resistor(s) will get
hot, smoke, stink, and NOT blow up the output stages. There will be a
loss in output power, which presumably he won't notice unless he's
running low impedance or low efficiency speakers.


[1] Cotton soaked in propylene glycol or white mineral oil which is
what we used for wind tunnel airflow visualization. Propylene glycol
doesn't stink very much, but white mineral oil really reeks.

--
Jeff Liebermann je...@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

[John Heath]

I have heard this argument too many times as if the costumer is responsible for electrical engineering issues. The customer paid for the amplifier leading a profit for the manufacturer. It is the manufacturer that is responsible to made sure the amplifier is idiot proof. Amplifiers have current limiting circuits which means you can sort the outputs all day long without any damage. If the manufacturer can not be bothered to be responsible for their own engineering leading to output transistor failure than they are in the wrong business. There is no such thing as a costumer that is wrong as he is the one that is paying the money. The failure is always up stream from the costumer. I will now get of my soap box.

[Trevor Wilson]

**I'm suprised that the shitbox Yammy can't handle a short. Part of the
test procedure for all the old 1970s Marantz amps, was to throw a short
circuit across the outputs. If it didn't survive, it would not be given
back to the owner (until it did).

--
Trevor Wilson
www.rageaudio.com.au

[Mark Zacharias]

"Jeff Liebermann" <je...@cruzio.com> wrote in message
news:m4sbfbtj3k3b1hcjn...@4ax.com...

You, sir - are an evil Genius!

mz

[Mark Zacharias]

"Trevor Wilson" <tre...@SPAMBLOCKrageaudio.com.au> wrote in message
news:dlmors...@mid.individual.net...

Not sure it was purely a direct short, or if it was a one-off. The emitter
resistor showed signs of longer term overheating. He's sure as hell doing
something wrong though. can't rule out a bad speaker either.

The whole thing requires further investigation.

He live a ways our of town from my location so a service call is at the
least inconvenient for me.

At the least I need to have him bring me the speakers and wires for
evaluation.

Mark Z.

[Mark Zacharias]

"Trevor Wilson" <tre...@SPAMBLOCKrageaudio.com.au> wrote in message
news:dlmors...@mid.individual.net...

If I recall correctly that procedure used a variac and the test stopped an a
certain current (I think it was 4 amps) through the amp meter which was the
only "load". A modern amp would pass that test as well, but the
microprocessor-based turn-on and protection circuits would have to be
bypassed.

Mark Z.

[Tim Schwartz]

I'll have side with the manufacturer here. It is not possible to make
any product 'idiot proof' as someone will come up with a bigger idiot.

By these this standard, car manufacturers should build a car that won't
sustain any damage because the driver is reading the newspaper, texting
or talking on a phone rather than driving. Or from a mechanical side,
not add oil when the light comes on. Not possible, at least not yet.
The end user must also take reasonable care.

Shorting speaker leads is NOT something that the manufacturer can make
idiot proof without significantly increasing cost and/or compromising
performance.

Regards,
Tim

[pf...@aol.com]

On Friday, March 25, 2016 at 11:53:02 PM UTC-4, John Heath wrote:

> I have heard this argument too many times as if the costumer is responsible for electrical engineering issues. The customer paid for the amplifier leading a profit for the manufacturer. It is the manufacturer that is responsible to made sure the amplifier is idiot proof. Amplifiers have current limiting circuits which means you can sort the outputs all day long without any damage. If the manufacturer can not be bothered to be responsible for their own engineering leading to output transistor failure than they are in the wrong business. There is no such thing as a costumer that is wrong as he is the one that is paying the money. The failure is always up stream from the costumer. I will now get of my soap box.

There is what I define as the Great Aunt Esmeralda issue:

Great Aunt Esmeralda is typically in her late 80s, but not frail. She has each and every one of her marbles, and is in full control of same. She is set in her ways, but neither stupid nor fearful. She resists change, but only because at her stage in life she has things right where she wants them. She also votes, every time for every election at every level and is known to do so.

As a concept, she is directly responsible for the delay of the shut-off of Analog TV in the US, until its advocates could develop a more intuitive interface. If Esmeralda had to diddle around to turn on her soaps, and missed the first five minutes of the show because the interface was not fully intuitive, she would make dammed sure her congressman knew it! Starting with her Alderman.

At the same time, Great Aunt Esmeralda understands that as a consumer, she has some responsibility to 'read the directions' as it were. And as a consumer/customer, to seek clarification when in doubt - and make damned sure that the provider of her goods and services writes directions that are able to be followed by any reasonable consumer with normal intelligence - NO MORE!

I have legacy amplifiers from AR, Dynaco, Revox and HK-Citation. EVERY ONE OF THEM cautions against shorting the outputs. Two manufacturers (AR & Dynaco) cautions against running their amplifiers with input, but no connected load. Each, in its own way, also cautions against shorting the two channels together. Several of them add protection circuits (Revox & Dynaco), some add fuses, internal or external (AR & HK) and so forth. And in every case, the directions are clear and unambiguous. Great Aunt Esmeralda would have no difficulty with them, and if she screwed up the connections resulting in a melt-down, she would be fully OK with accepting the consequences.

What you suggest is similar to making an automobile manufacturer liable for the consequences of the fact that the accelerator and brakes may be applied at the same time.... Driver error (pilot error/user error) is a real phenomenon such that reasonable accommodations must be made, but the danger of same cannot be obviated.

Against stupidity the very gods
Themselves contend in vain.

Schiller.

[Jeff Liebermann]

On Sat, 26 Mar 2016 06:11:45 -0500, "Mark Zacharias"

<mark_za...@sbcglobal.net> wrote:

>"Jeff Liebermann" <je...@cruzio.com> wrote in message
>news:m4sbfbtj3k3b1hcjn...@4ax.com...
>> On Fri, 25 Mar 2016 05:48:15 -0500, "Mark Zacharias"
>> <mark_za...@sbcglobal.net> wrote:
>>
>>>Cautioned him on speaker hook-ups, gave him our hand-out sheet explaining
>>>speaker connections,
>>>which also contains explicit warnings about shorting wires etc.
>>
>> Put a 0.5 ohm xx watt resistor in series with each speaker. Paint the
>> resistors with whatever concoction generates the most noxious smoke
>> possible[1]. Then he shorts the leads again, the resistor(s) will get
>> hot, smoke, stink, and NOT blow up the output stages. There will be a
>> loss in output power, which presumably he won't notice unless he's
>> running low impedance or low efficiency speakers.
>>
>>
>> [1] Cotton soaked in propylene glycol or white mineral oil which is
>> what we used for wind tunnel airflow visualization. Propylene glycol
>> doesn't stink very much, but white mineral oil really reeks.

>You, sir - are an evil Genius!
>mz

Thank you. Think of it as a VERY slow blow fuse with a built in
"indicator". I suspect that even the most dense customer will
recognize smoke as an indication that perhaps something is very wrong.

Many years ago, when I was an aspiring juvenile delinquent, I removed
one end of a 3AG cartridge fuse, stuffed it with cotton, added a few
drops of 3-in-1 oil, installed a 0.5 ohm resistor, and somehow
soldered it back together without starting a fire. I'll pretend not
to remember how I did that. The plan was to make some sort of bomb to
irritate some of my friends. Instead of exploding, it produced a
substantial amount of smoke and attracted some unwanted official
attention. While I don't believe that the world needs a smoking fuse,
a similar leaded component might sell to like minded dangerous
individuals, such as myself, as an over current alerting system. With
some additional complexity, I could add a chemical timer set to
slightly longer than the warranty period. I have some ideas on how to
do an SMT version.

Hmmm.... Kickstarter perhaps?

[Jeff Liebermann]

On Fri, 25 Mar 2016 20:52:58 -0700 (PDT), John Heath
<heath...@gmail.com> wrote:

>I have heard this argument too many times as if the costumer
>is responsible for electrical engineering issues. The customer
>paid for the amplifier leading a profit for the manufacturer.
>It is the manufacturer that is responsible to made sure the
>amplifier is idiot proof. Amplifiers have current limiting
>circuits which means you can sort the outputs all day long
>without any damage. If the manufacturer can not be bothered
>to be responsible for their own engineering leading to output
>transistor failure than they are in the wrong business.
>There is no such thing as a costumer that is wrong as he is
>the one that is paying the money. The failure is always up
>stream from the costumer. I will now get of my soap box.

In the past, when I needed some entertainment, I would read product
liability horror stories. It eventually became somewhat of a hobby
until I was overwhelmed with horror stories.

Your position is quite among customers and product liability
attorneys. The legal responsibility is a moving target, varying
depending on court decisions, commercial law, and both state and
federal laws. Over the years, it has swung in both directions, but at
no time has it ever been absolute. The manufacturer, retailer, and
customer all have their areas of responsibility with considerable
overlap.

Very briefly, the courts have recognized that manufacturers cannot
produce a 100% safe and reliable product. If they did, nobody could
afford it anyway. One compromise is that if a manufacturer can show
due diligence in informing the end user that there are some hazards
involved in using the product, and the customer is assumed to have
been so informed, then the customer cannot claim that they destroyed
the product or injured themselves in the manner specified in the
documentation. This is where the ever growing mass of legal documents
and "read me first" papers originate. If the manual warns that
shorting the speaker output is a bad idea, the court will not award
the customer damages if they ignore the warning and short the speaker
leads.

The other side of this coin is whether a "reasonable person" expects
products to operate in some manner. In this case, if literally every
other audio amp manufacturer includes speaker short circuit protection
in their products, but this one does not, a reasonable person would
probably expect that every amp is short circuit proof. Depending on
the court, that could be considered sufficient for the customer to
claim that they did not receive a product "suitable for the intended
purpose".

With today's low cost of electronic manufacturing, it is often cheaper
for a manufacturer to replace the few amps that a few clueless
customers manage to blow up, than to include protection circuitry in
every product. For example, if adding the protection circuitry
required an additional $5 in parts and Yamaha made 250,000 of these
amps, then that's $1.25 million in "excess" cost. However, replacing
perhaps 1,000 amplifiers, at a cost to sales of about $50/ea or
$50,000 is much cheaper. This is probably why Yamaha honored the
warranty.

If you have an questions, please consult a real attorney.

[Adrian Caspersz]

A friend blew up the RF power amp on an Icom 2m Transceiver by reverse
connecting his car DC supply to the rig. A rig borrowed from the club
shack. Much tears ;-(

It did have the diode that you describe reverse connected across the
supply. Unfortunately that diode either didn't conduct fast enough, or
decided it wasn't going to be part of the game and went open circuit
before the fuse (and the amp... ) ...


--
Adrian C

[jurb...@gmail.com]

>"f you have an questions, please consult a real attorney. "

HA. Half of them are incompetent and the other half, well...

Used to work for one of those rental joints. Handled the repairs for the area, approximately the county. They reanted BFC SFS Fisher stereo systems using the CA-270 (discrete) amplifier. I worked on many of them. Underbuilt, and on purpose.

Looking at the PC board it was easy to see that it was designed to have commutators. The thing was considerably over 100 WPC and only had one pair of outputs per channel. You can get away with that with a commutating power supply. Also by the relay you could see the traces for what was obviously an offset detector.

All these parts were gone. By the relay all that was left was the time delay and the commutators were simply jumped out and all related components were omitted.

We replaced so many woofers because of that it ain't funny. Eventually the service manager got a source for some practically bulletproof woofers, I mean woofers that would stand up to 60 volts DC until the fuse blows. At least that was solved. Kinda.

Thing is, transistors and diodes are cheap. If I were on that side of that desk I would have them in there. However, in the US at least, the quarterly report is king.

Like this joke... A new CEO of a company gets three envelopes from the old CEO, tells him open them when things get tough. Sales drop later and he opens the first envelope and there is a note saying "Blame your predecessor". He does and all is fine, but later then sales and profits drop again, he opens the seconfd envelope and the note says "Reorganize". Well that works but then things go badly again later so he opens the third envelope and the note inside says "Get three envelopes and..."

As long as we publicly trade debt on these companies, they are bound to suck up the most money every day possible, It is fucking up the world, and the environment. In fact, if we cared enough to do something about it we would take the "green" attitude and let the democrats have at it. Laws that say you have to have parts for TVs n shit for like five years or so, instead of having them no longer available even during the warranty period. (this has happened) But even with that, can the government control the prices ? This is where they fucked up on the ACA, the price controls are not firm. Right now health insurance companies want doctors and hospitals to fuck them out of as much money as possible so they can make 20 % on it. Shit, oil companies would suck a mile of donkey dick to make 20 %.

The informed and non-addicted consumer is the best weapon here. Like "My TV was only two years old and it couldn't be fixed, I went to buy one with a long warranty but they had none, so now I DO NOT HAVE A TV". Start that shit and you won't need a grass roots lobby organization, the TV networks, cable companies and even Hollywood would do the lobbying for you.

But there is no solidarity among the sheeple. No chance to put up a serious boycott of anything. Anything. This is the age of instant gratification. Pitiful fucking species they are.

[pf...@aol.com]

On Saturday, March 26, 2016 at 2:26:52 PM UTC-4, jurb...@gmail.com wrote:
> >"f you have an questions, please consult a real attorney. "
>
> HA. Half of them are incompetent and the other half, well...

Shakespeare had it dead-right in his play Henry VI. Killing the lawyers was the sure route to tyranny, not the means to restore sanity to society.

Keep in mind that it is "society" that gives or has given us every evil from the Crusades to Jihad and ISIS, from Empress Wu to Donald Trump. Society is essentially insane, and functions only through pitiless and unrelenting control. Where such control has been destroyed, all remnants of societal function have failed. Modern examples include former strong-man states (Libya, Afghanistan, Iraq) where leadership was removed, not deposed. States where leadership was deposed (Iran, Soviet Russia, Balkans amongst others) function today after a fashion, and after an often horrendous shaking out - but they function none-the-less.

Circling back to electronics - we get exactly what we deserve, neither more nor less. It is entirely possible to purchase well-made electronics that are maintainable and have a truly indefinite service life - with that maintenance. Including all consumer entertainment electronics in this household, the newest daily-driver type item is a 6-year old blue-ray player to match the 8 year old plasma TV. The oldest is a 1962 tube stereo amplifier. If hobby (and functional) electronics are included, that would be a 1919 5-tube home-brew TRF radio driving a Magnavox horn.

If that first pair of $3.29 pair of Chinese underwear stayed on the shelf for the $3.69 pair of home-country underwear, we would not have this issue. But we are all-to-fast ready to give up our neighbor's jobs to 'save' that $0.40. Not quite understanding that without our neighbor's jobs our own are not long for this world.

Sorry for the insertion of politics here - but feeling sorry for ourselves is the last collective and several refuges for cowards. And "Let George Do It" is how we got here in the first place. The Chinese have not "taken" one single job from any one any where at any time. They were handed each and every one of those jobs complete and together with the plea "PLEASE take this burden from us!"

And. Lest ye "first world" people think for one hummingbird heartbeat that control over *you* is not pitiless - consider how much *you* are regulated, and at every turn. Between taxes, leases, licenses of various sorts, permits, insurance, credit cards, cash-transaction limits, speed limits, stop lights, parking meters, passports, health insurance, deeds, titles and on and on and on...

Put another way, Anarchy Bitch.

[Ralph Mowery]

"Adrian Caspersz" <em...@here.invalid> wrote in message
news:dlo26c...@mid.individual.net...

.
>
> A friend blew up the RF power amp on an Icom 2m Transceiver by reverse
> connecting his car DC supply to the rig. A rig borrowed from the club
> shack. Much tears ;-(
>
> It did have the diode that you describe reverse connected across the
> supply. Unfortunately that diode either didn't conduct fast enough, or
> decided it wasn't going to be part of the game and went open circuit
> before the fuse (and the amp... ) ...
>

Usually the most expensive part blows open to protect the fuse.

[jurb...@gmail.com]

pf, politics is what started this shit.

I used a slightly different analogy.

When you walked into Kmart and saw TVs on the shelf, a Zenith for $279 and a Sanyo for $229 you pocketed that fifty bucks and went and had a good time on it. Well the good times are over because YOU told the industry that cost is King, that you want it cheaper. You did not care about build quality, or this country and its well being. You wanted that half a yard in your wallet.

Time marched on and the results are in. We are fucked.

I see you think like me to some extent. Have ANY ideas on how to fix this shit without removing 90 % of the population ? I can't figure anything out. Even massive killing wouldn't work. NOTHING will work.

Reminds me of a joke about an old Indian. (American) Guy asks him about what he thinks about White Man. He replies "We had it good, Women did most of the work, we hunted and fished every day, no taxes, no debt, no problems. Only White Man stupid enough to think he can improve on that".

Progress. Think about progressives. Now think about conservatives who wanted to keep things the same, for better or worse. In fact republicans freed the slaves. Things seem to have flip flopped.

Slavery is a barbaric thing and should not be allowed in any civilised society. It is illegal in most parts of the world, but not in Israel and a few other countries in that region and in Asia and Africa. And that saying about "we should have picked our own cotton" has come true eventually for most countries that had slaves. Now it seems we should have picked our own oil.

But there are no true conservatives. I think the last one was Barry Goldwater, and he warned against letting the religious folk get hold of the republican party, because governance is all about compromise and people who think they are speaking for god will not compromise.

While he was right, he did not realize that later (like now) that these people would not be religious at all, but feign it for church support. And that is important in some districts. Like against homosexuals until their son comes out of the closet. Or against abortion but sends their mistress for a D & C when she gets knocked up by their adultery. Fucking hypocrites to the core.

Nixon was more of a Man and more honest than any of them today. Think about it, if you are doing backdoor deals and being dishonest, do you want tape recordings of it ? some say he did that because he was paranoid but the fact is they were out to get him. I believe he benefitted from the Watergate breakin, but I still do not believe he ordered it. However, like the impeached Bill Clinton and the assassinated JFK, he spoke against Israel. Most people do not know that alot of this shit happened right after they said mean shit to Israel.

So, with no true conservatives we are stuck with the liberals or oil company executives. That is your choice. Who are you going to vote against this time ?

[pf...@aol.com]

On Saturday, March 26, 2016 at 5:17:54 PM UTC-4, jurb...@gmail.com wrote:
> pf, politics is what started this shit.

> I see you think like me to some extent. Have ANY ideas on how to fix this shit without removing 90 % of the population ? I can't figure anything out. Even massive killing wouldn't work. NOTHING will work.

I am not so sure we think much alike. My politics as-practiced are considerably left of center, although not quite socialist. Mostly based on personal responsibility, the social contract and the basic fact that the world owes me nothing.

At the same time, the Human Race if seen as the functional equivalent of mold on an orange is doing a very efficient job of killing itself off, and apparently sooner rather than later. No problem for me, likely not for the kids either. But the grandkids are going to have a brutal time of it. A few tens of thousands of years from now, we will of interest only to whatever passes for archaeology and paleontology at the time, if even that. So, why sweat the small stuff with that perspective?

As of this moment, and based on present absolutely provable facts and long-term trends, the Malaysian archipelago land mass will be reduced by 70% (or more) by 2050. The present population is just under 30,000,000. And there is not one damned thing that you, I, or anyone else, collectively and severally, can do about that. AND, that is one single example. Florida - what happens when 30% of that state can no longer support either farming or a human population? New Jersey (small loss)? The entire Gulf Coast? Not to mention California. Just keeping it "American" here - the rest of you are also quite done, just not fully aware of how done, quite yet.

That we are fucked is absolute. That it is of our own making, equally so. But as a species we have always been better and destruction than at creation. Always. This particular disaster is pandemic, having nothing to do with race, color, creed, nation, state, orientation or personal preferences. Like a flat tax, we are all equally affected whether we like it or not.

[jurb...@gmail.com]

I think collectivism and individualism can coexist, but we have not figured the method.

[Jon Elson]

Tim Schwartz wrote:


> I'll have side with the manufacturer here. It is not possible to make
> any product 'idiot proof' as someone will come up with a bigger idiot.

I make a line of PWM servo amplifiers, using a bunch of TO-220 FETs. A
mechanical engineer bought some, and saw those little plastic things clamped
under the transistors and decided they couldn't conduct heat well, so he
took them out, put a glob of thermal grease under them and clamped them down
tight. Hooked the whole system up and turned it on. There was a
thunderclap and a huge flash, and everything he had bought from me was
reduced to charred rubble. The little plastic things were good Bergquist
thermal conductive pads, and work fine to allow the amp to run at 20 A
continuously. I fixed one amp just to see how bad it was, well every semi
in the thing was toast. It must have got +80 V into the +12 logic supply.

That's the biggest idiot I've had so far...

Jon

[Trevor Wilson]

**Apart from the Variac™, pretty much it. I must admit some trepidation
the first few times I was required to perform this test.

[stra...@yahoo.com]

Had one like yours with the fuse and protect diode blowing. Second time I had to repair it I checked what he was actually doing and found the reverse polarized battery. His car was an early '60 Ford van with a generator, NOT an alternator and when the battery was dead he jumped it backwards and converted it to positive ground.

G²

[jurb...@gmail.com]

>"His car was an early '60 Ford van with a generator, NOT an >alternator and when the battery was dead he jumped it backwards and >converted it to positive ground. "

Yup. And if the radio was all tubes it would run just fine. No way to tell without a meter.

[Michael A. Terrell]

"pf...@aol.com" wrote:
>
> N_Cook wrote:
> >
> > I have a customer who keeps breaking things, often fatally, because he
> > picks up the nearest wallwart, having mislaid the original one, because
> > it looks the same size black lump and the connector pushes in, so it
> > must be ok .
>
> Once upon a time, there was movement to color-code and size-code these things... It never quite took.


Have you seen these adapters?

http://www.ebay.com/itm/171829811403

[pf...@aol.com]

I have. Sadly, it was the south end where the color-coding never took, not the north end.

[Cydrome Leader]

When would you use a diferent preamp, or different power amp in an
integrated unit anyways? Anything with the shunts was already packed with
all sorts of silly inputs to start with.

[Cydrome Leader]

It is sort of sad it can't handle that. Just a few warranty service calls
would pay for hundreds or thousands of fuse to have been installed.

[Trevor Wilson]

**Fuses open in seconds. Semiconductors can fail in MILLISECONDS. Active
current limiting is the best solution.

[jurb...@gmail.com]

>"When would you use a diferent preamp, or different power amp in an
>integrated unit anyways? Anything with the shunts was already packed >with
>all sorts of silly inputs to start with. "

Preamps can make as big a difference in the sound as power amps. People also get to liking how they hook up, all their shit fits. They like the tone controls, and that is a big one. some of those old 25 WPC Marantzes had fantastic preamps and tuners, but now the guy went and bought some speakerzillas and needs more power. So he picks up an ampzilla somewhere but wants the rest of his system to stay the same. He likes how it looks and sounds, just needs more power.

That's why, and it really is not audiophoolery, just one of thoise things.

I had a Marantz 4270 I ran in strsapped mode for the front to get the more power (clipped at 154 watts per channel in bridged mode) and used the rear pre outs to feed a Sansui 771 into 2.3 ohms for the back which had modified speakers. They originally had passive radiators but I put speakers in there instead. Then I had to use an EQ (Soundcraftsmen PE2217) to get the sound right.

Purists can bitch and moan about using EQ like that but what about the Bose 901 ? The EQ for that has about a 30 dB range that a standard graphic EQ cannot do. So if that is OK then my system was OK.

All of this shit can sound different, so if you got a receiver or amp and like the sound, you can keep it. Also, people are getting back into vinyl and phono preamps are not all created equal. All over the place the audiophiles say my Soundcraftsmen has a shitty phono stage, that it sounds harsh. Well I never used it, I used the EQ and it is one of the best EQs I have ever seen. Uses real coils, and the way it is configured, when you get to the extremes in the ranges, they are pretty much effectively in parallel. the chip based ones cannot do that and give you camel humps in the response. I can show you on a scope with a 1 KHz square wave.

People do crazier shit than that when it comes to stereo equipment. Some go nuts and claim one speaker wire sounds better, I do not go for that. Unless the resistance is very high it makes no difference. And like the cables, RCA type, the only thing that matters in them is the capacitance per foot. A cable from a turntable with a moving coil cartridge, maybe. then you might need superior shielding. but for the rest of it, for electronic sources like a CD player or tape deck, you almost do not need shielded cables. I'll use Romex from a CD p;layer to an amp and nobody will hear the difference, or might actually think the Romex sounds better !

Learning a little bit of math and electronics makes you aware of what really matters and what does not.

[jurb...@gmail.com]

>"**Fuses open in seconds. Semiconductors can fail in MILLISECONDS. >Active
>current limiting is the best solution. "

Yeah like when seconds count, the cops will be there in minutes. Completely true. The problem is the implementation.

Active current limiting tends to make bad bad distortion on low impedance loads. It sounds as if a speaker is blown or a woofer is bottoming out.

I have tried to figure out a better way but am at a loss on that, so I understand why they did it. It protects their product from abuse and unnecessary warranty claims. And it was cheap, couple transistors, diodes, maybe six resistors in all.

The alternative is to use a relay and a latch, which is run through the uProcessor on newer shit and it reads "Protection" on the display. I am not fond of those type of circuit because it makes it harder to troubleshoot.

I think they should make amp ready to drive one ohm loads, but then they would be more expensive and sales would be lost.

[Trevor Wilson]

On 29/03/2016 11:39 AM, jurb...@gmail.com wrote:
>> "**Fuses open in seconds. Semiconductors can fail in MILLISECONDS.
>> >Active current limiting is the best solution. "
>
> Yeah like when seconds count, the cops will be there in minutes.
> Completely true. The problem is the implementation.
>
> Active current limiting tends to make bad bad distortion on low
> impedance loads. It sounds as if a speaker is blown or a woofer is
> bottoming out.

**Nonsense. There are several methods of implementing current limiting,
which do not impact severely on sound quality. If the current limiting
can be kept out of the global NFB loop, then the result can be very benign.

>
> I have tried to figure out a better way but am at a loss on that, so
> I understand why they did it. It protects their product from abuse
> and unnecessary warranty claims. And it was cheap, couple
> transistors, diodes, maybe six resistors in all.
>
> The alternative is to use a relay and a latch, which is run through
> the uProcessor on newer shit and it reads "Protection" on the
> display. I am not fond of those type of circuit because it makes it
> harder to troubleshoot.
>
> I think they should make amp ready to drive one ohm loads, but then
> they would be more expensive and sales would be lost.
>

**That is the way high quality products do it.

[jurb...@gmail.com]

>"**Nonsense. There are several methods of implementing current >limiting,
>which do not impact severely on sound quality. If the current >limiting
>can be kept out of the global NFB loop, then the result can be very >benign. "

They're all benign when not active. I am talking about when they are working actively limiting current. Maybe I didn't make that clear.

But if I did, and there is a scheme that will limit the current actively without that harsh distortion, show me. A model number will do now that with the internet I can usually get a print.

I saw one, in fact owned it. But it was not DC coupled and I don't remember the model. It was a Realistic integrated amp, maybe 40 WPC or something like that. Overload it and it seemed like the gain decreased, it didn't bark at you. But it also was not all that high end or high power.

>"**That is the way high quality products do it. "

At the cost of market share of course. I agree though, just build it right and use like 12 amp speaker fuses.

HA, I remember Heathkit touted that their speaker fuses were in the feedback loop. Actually, the audiophile crowd kinda likes them.

[Trevor Wilson]

On 30/03/2016 3:34 AM, jurb...@gmail.com wrote:
>> "**Nonsense. There are several methods of implementing current
>> >limiting, which do not impact severely on sound quality. If the
>> current >limiting can be kept out of the global NFB loop, then the
>> result can be very >benign. "
>
> They're all benign when not active. I am talking about when they are
> working actively limiting current. Maybe I didn't make that clear.

**And I explained that, if the current limiting system can be kept out
of the NFB loop, then it's action can be benign.

>
> But if I did, and there is a scheme that will limit the current
> actively without that harsh distortion, show me. A model number will
> do now that with the internet I can usually get a print.

**Do the analysis based on my description. I am aware of at least a
dozen products where the current limiting system is not contained within
the NFB loop and the result is gentle limiting. Schematics are not
generally available, AFAIK.

>
> I saw one, in fact owned it. But it was not DC coupled and I don't
> remember the model. It was a Realistic integrated amp, maybe 40 WPC
> or something like that. Overload it and it seemed like the gain
> decreased, it didn't bark at you. But it also was not all that high
> end or high power.

**There you go. I know of one amp that used a simple lamp to limit
current through the output stage under overload.

>
>> "**That is the way high quality products do it."
>
> At the cost of market share of course. I agree though, just build it
> right and use like 12 amp speaker fuses.

**No high end amplifier uses non-linear resistors (aka: fuses) in series
with speakers. To do so, would be the antithesis of high fidelity.

>
> HA, I remember Heathkit touted that their speaker fuses were in the
> feedback loop. Actually, the audiophile crowd kinda likes them.
>

**Not me. Fuses should be there to prevent fires. Nothing more.

[pf...@aol.com]

On Tuesday, March 29, 2016 at 4:00:24 PM UTC-4, Trevor Wilson wrote:

> **No high end amplifier uses non-linear resistors (aka: fuses) in series
> with speakers. To do so, would be the antithesis of high fidelity.

Please explain with other than anecdotal information. This reads suspiciously like advocating high-cost interconnects, line cords, and speaker wires....

[Trevor Wilson]

**Now you're being silly. Measure a fuse sometime. The resistance
increases, as current increases. It acts as a non-linear resistor. The
ONLY place for a fuse is before filter capacitors in an amplifier. In
the DC lines, or the speaker lines, fuses introduce distortion and
should not be used. This is electronics 101.

For the record:

* People using fancy power leads are deluded. The best power leads are,
of course, old style captive ones. IEC connectors are convenient and
stupid. They allow consumers to be conned into changing power leads
needlessly.
* People using *LOW INDUCTANCE*, *LOW RESISTANCE* speaker cables may
not, necessarily, be deluded. Again: Electronics 101.

Here are a couple of examples why such speaker cables may be useful:

http://www.rageaudio.com.au/modules/gallery/view.php?a=Accustat&image=091027105452_accu.jpg
http://www.rageaudio.com.au/modules/gallery/view.php?a=Kappa9&image=090801082656_kappa9.jpg


Never throw the baby out with the bathwater. Electronics 101.

[Trevor Wilson]

On 25/03/2016 9:48 PM, Mark Zacharias wrote:
> How is it a grown man cannot understand the concept of keeping two wires
> separate?
>
> Fixed a Yamaha RX-A2010 with a blown channel back in December.
>
> Under warranty.
>
> Big job.
>
> Cautioned him on speaker hook-ups, gave him our hand-out sheet
> explaining speaker connections,
> which also contains explicit warnings about shorting wires etc.
>
> Nevertheless he brought it back this week with the same channel blown
> again.
>
> It was all I could do not to just go off on the guy. He admitted fooling
> around with the wires while the unit was powered up, and that the wires
> had crossed. Exactly the sort of thing I had "educated" him about.
>
> Fucking idiot. Lucky for him Yamaha is covering it again, and we needed
> the work anyway.
>
> Shit for brains god damn idiot. I knew better that this when I was
> sixteen fucking years old!
>
> I'm reminded of Chevy Chase's rant in Christmas Vacation...
>

**I have only done once or twice, but with a couple of recalcitrant
clients, I have installed Polyswitches into their equipment. Mostly
speakers, but sometimes amplifiers.

[pf...@aol.com]

On Tuesday, March 29, 2016 at 6:58:21 PM UTC-4, Trevor Wilson wrote:

>
> **Now you're being silly. Measure a fuse sometime. The resistance
> increases, as current increases. It acts as a non-linear resistor. The
> ONLY place for a fuse is before filter capacitors in an amplifier. In
> the DC lines, or the speaker lines, fuses introduce distortion and
> should not be used. This is electronics 101.

Silver-link fuses using an eutectic formula add negligible resistance within their ratings. Nor are they cheap. As you well know, silver is the closest thing to a super-conductor at any reasonable operating temperature as exists in nature, much better than copper (or gold), and so such fuses ought to be considered.

Example: I keep speakers from a current manufacturer that would cost me well over US$7,000 to replace today. A few bucks on fuses to protect this investment is well worth it. That I researched dual-element silver-bearing fuses to minimize any downside from adding such a device makes the choice both worth it and (probably) wise. A defective amp is not likely to gradually ramp up into the speakers, it is likely to surge - at least in my experience. So, I can run the fuse very close to the overall speaker rating letting the dual-element section handle high musical peaks without sacrificing (much) protection.

Keeping in mind that as you suggest, low-resistance speaker connections are a 'good' thing, I use #12 fine-stranded (19 strands) THHN wire for speaker leads, spun in a drill to reduce capacitance does well for short runs and is remarkably cheap at ~US$0.27/foot (both stands included).

But, a fuse on a $3,500 speaker?

Wouldn't you?

Peter Wieck
Melrose Park, PA

>

[Trevor Wilson]

On 31/03/2016 3:30 AM, pf...@aol.com wrote:
> On Tuesday, March 29, 2016 at 6:58:21 PM UTC-4, Trevor Wilson wrote:
>
>>
>> **Now you're being silly. Measure a fuse sometime. The resistance
>> increases, as current increases. It acts as a non-linear resistor.
>> The ONLY place for a fuse is before filter capacitors in an
>> amplifier. In the DC lines, or the speaker lines, fuses introduce
>> distortion and should not be used. This is electronics 101.
>
> Silver-link fuses using an eutectic formula add negligible resistance
> within their ratings. Nor are they cheap. As you well know, silver is
> the closest thing to a super-conductor at any reasonable operating
> temperature as exists in nature, much better than copper (or gold),
> and so such fuses ought to be considered.

**Perhaps.

>
> Example: I keep speakers from a current manufacturer that would cost
> me well over US$7,000 to replace today. A few bucks on fuses to
> protect this investment is well worth it. That I researched
> dual-element silver-bearing fuses to minimize any downside from
> adding such a device makes the choice both worth it and (probably)
> wise. A defective amp is not likely to gradually ramp up into the
> speakers, it is likely to surge - at least in my experience. So, I
> can run the fuse very close to the overall speaker rating letting the
> dual-element section handle high musical peaks without sacrificing
> (much) protection.
>
> Keeping in mind that as you suggest, low-resistance speaker
> connections are a 'good' thing, I use #12 fine-stranded (19 strands)
> THHN wire for speaker leads, spun in a drill to reduce capacitance
> does well for short runs and is remarkably cheap at ~US$0.27/foot
> (both stands included).
>
> But, a fuse on a $3,500 speaker?
>
> Wouldn't you?
>

**I am 62 years old. I've been listening a sound system since I built my
first one at age 17. In my 20s, I purchased my first home and proceeded
to assemble a sound system to please myself and my friends at various
parties. It also drove my neighbours a little nuts. This is the
amplifier I used to drive my KEF transimssion lines (rated at 50 Watts)
at many, many drunken parties:

http://audio-database.com/MARANTZ/amp/model500-e.html

I still own the best, but no longer use it. I certainly don't operate my
sound system at the kinds of levels I once did. I also use vastly more
sophisticated amplification nowadays (soft clipping, soft current
limiting, etc).

In my entire 45 years of listening, I only ever damaged one of the B139
drivers. The reason the driver failed was due to poor assembly at the
KEF factory. So, no. I would not put a fuse on a speaker of MINE. I
don't damage speakers. For all intents, I never have. For customers, the
situation is different. For headbangers, I will certainly suggest the
use of polyswitches or fuses, as the safety outweighs any potential
downside. I would certainly not install a fuse or Polyswitch in any high
end system, unless the client and I decided it was prudent. I did so
with these speakers, after long consultation with a client however:

http://elac.ro/elac%20x-jet%203.jpg (exploded diagram of the mid/HF driver)

The HF element (equivalent to a Heil unit) had failed, after his
children accessed his hi fi) was not repairable. A new driver had to be
sourced at almost AUS$1,000.00.

So yes, I fitted Polyswitches to protect the drivers.

[Cydrome Leader]

pf...@aol.com <pf...@aol.com> wrote:
> On Tuesday, March 29, 2016 at 6:58:21 PM UTC-4, Trevor Wilson wrote:
>
>>
>> **Now you're being silly. Measure a fuse sometime. The resistance
>> increases, as current increases. It acts as a non-linear resistor. The
>> ONLY place for a fuse is before filter capacitors in an amplifier. In
>> the DC lines, or the speaker lines, fuses introduce distortion and
>> should not be used. This is electronics 101.
>
> Silver-link fuses using an eutectic formula add negligible resistance within their ratings. Nor are they cheap. As you well know, silver is the closest thing to a super-conductor at any reasonable operating temperature as exists in nature, much better than copper (or gold), and so such fuses ought to be considered.

powerline expulsion fuses use silver wire as the element. I was told
nothing is as reliable during a factory tour.

[Michael A. Terrell]

I bought them for the workbench, i really don't care that they are
color coded like other adapters I have that are the wrong voltage. A
cable connected to a 0-20V 3A HP 6253A power supply on the bench lets me
power almost any DC powered device to see if it works, or to repair the
ones that don't. No need to modify an existing supply, just to see if
something works. :)

[Phil Allison]

pf...@aol.com wrote:

>
> Silver-link fuses using an eutectic formula add negligible resistance
> within their ratings. Nor are they cheap. As you well know, silver is
> the closest thing to a super-conductor at any reasonable operating
> temperature as exists in nature, much better than copper (or gold),
> and so such fuses ought to be considered.
>
>

** Silver is only 6% more conductive than copper, has the same tempco of resistance and a lower melting point. A silver or copper wire fuse increases its resistance by at least 4 times before opening.

OTOH, a tin fuse with a far lower melting point than either, increases in resistance by less than double before opening. Often made as a flat strip with a neck in the middle, they are semi slow-blow too.

Fine for loudspeakers.


.... Phil

[Phil Allison]

Trevor Wilson wrote:

>
>
> **Now you're being silly. Measure a fuse sometime. The resistance
> increases, as current increases. It acts as a non-linear resistor. The
> ONLY place for a fuse is before filter capacitors in an amplifier. In

> the DC lines, or the speaker lines, fuses introduce distortion ...
>

** On the DC lines there is always lots of 100Hz ripple AND *half wave* signal voltage imposed on the wiring and filter cap ESR - which the PSRR of the amp rejects anyhow.


> This is electronics 101.
>

** Only on planet Wilson.


.... Phil