Nobody Would Ever Figure This One (amp)

This is worse than the adjust vertical height to correct a greyscale proble m.

Had this JBL Pro powered sub with a Crown 600 WPC amp in it. They did every thing they could to make it impossible to service of course but I did it. M odel MP418SP.

Symptom was that it would power up and then when you put input to it it wou ld start clicking, LOUD. And then it would not stop.

Ran it down to a bad connection to one of the main filter caps. the negativ e one IIRC. Yup, the negative one.

Must have been an oscillation set up with the protect and mute curcuits, so mething like that. I never thought an amp would act like that because of th at fault.

You know, ther are a few things about Crown, well I am not impressed. It's not just that heir prints are hard to follow, they all are. It's just some of the things they do, especially when it comes to the build.

Jaros from Poland told me "Don't use logic to fix things, it does not vork" . I am stsarting to think that many times, that statement is correct. I was about to start looking into the active crossover and all this, got the pri nt (well part of it) and all that. Then after hours I ge thte thing apart e nough and see this. Damn.

If you ever get one of those MP418SPs in be sure to charge alot of money. O f all tthis other shit, they used silicone to put the one corner of the boa rd down, and the rectifier is screwed to the plate where you can't get your hand in there.

Well at least the screws were not shitty or easily strippable or stuck. I c an give it that much. But really, I hope I never see it again.

Tick tick tick, LOUD, and it would not start until you put input to it, and after that it would not stop until power down.

How come it even came out of protection in the first place ?

Rant over.

Reply to
jurb6006
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** Always expect parts to vibrate lose with powered speakers. Yep - electros, WW resistors, anything on a PCB heatsink, coils, PCB transformers etc. Bout the only bits that stay put are SMD.

.... Phil

Reply to
Phil Allison

HA. This was the first time I ever saw SMD emitter resistors fro the outputs. Two 0.4 ohm per transistor, six pairs per channel.

There are alot of thoings I don't like about how that thing is designed but oh well.

Reply to
jurb6006

On Thursday, February 19, 2015 at 1:47:07 AM UTC-5, snipped-for-privacy@gmail.com wrote :

lem.

rything they could to make it impossible to service of course but I did it. Model MP418SP.

ould start clicking, LOUD. And then it would not stop.

ive one IIRC. Yup, the negative one.

something like that. I never thought an amp would act like that because of that fault.

s not just that heir prints are hard to follow, they all are. It's just som e of the things they do, especially when it comes to the build.

k". I am stsarting to think that many times, that statement is correct. I w as about to start looking into the active crossover and all this, got the p rint (well part of it) and all that. Then after hours I ge thte thing apart enough and see this. Damn.

Of all tthis other shit, they used silicone to put the one corner of the b oard down, and the rectifier is screwed to the plate where you can't get yo ur hand in there.

can give it that much. But really, I hope I never see it again.

nd after that it would not stop until power down.

I had three Sony double cassette decks that belong to a friend and had been in storage for years come in here for repair recently. I should have walke d away from this but he is a friend and I do have a sizable cassette collec tion myself.

They all needed flat belts. I should also have expected the other stuff I s ubsequently found too but sadly I didn't think to. Some of these belts had just lost their elasticity, and some had simply turned to black goo.

If it had been anyone else I probably would have returned these miserable u nits as soon as I got a look inside, but I stupidly went about trying to di sassemble/reassemble these God awful pieces of shit, all of them. I wound u p finding all types of other problems, worn parts, bad clutches etc. and wa sted a whole bunch of time.

These decks which were ultimately returned un repaired, I'm almost convince d that they must have been designed by the same assholes who designed my 20

00 Oldsmobile Bravada. I recently changed the spark plugs. I'll spare the d etails but it was a five hour job. Lenny
Reply to
captainvideo462009

Get a new:

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$89

You can get new cassette decks which can also connect to the pc and convert the cassette audio to mp3 for under 100USD.

Don't waste time with old stuff, if it is not of unusual good quality.

Leif

--
Je suis Charlie
Reply to
Leif Neland

I'm not impressed with Crown or Peavey for that matter. There were several times I was thinking to myself, "Why did they do that?"

I saw the other day the tv show "Undercover Boss" which went undercover at Peavey. Yup, I saw Peavey is still just as bad as they always have been. If anyone gets a chance, check out that episode, it's a riot!

Personally, I prefer QSC brand amplifiers for commercial use. They hold up quite well.

Reply to
Ken Layton

I'm not impressed with Crown or Peavey for that matter. There were several times I was thinking to myself, "Why did they do that?"

I saw the other day the tv show "Undercover Boss" which went undercover at Peavey. Yup, I saw Peavey is still just as bad as they always have been. If anyone gets a chance, check out that episode, it's a riot!

Personally, I prefer QSC brand amplifiers for commercial use. They hold up quite well.

In that case you might also want to consider the Behringer EP4000. (Unless of course the name Behringer clouds your judgement)

Allegedly a QSC clone but a whole lot cheaper, and a 3 year warranty at that price makes it a no brainer.

Gareth.

Reply to
Gareth Magennis

Wow and flutter ? Frequency repsonse ? Distortion ?

Same with those USB turntables. I got an old Dual I''ll stick a gartridge i n and run it through my Marantz CD-400B. It has specs. Not wow and flutter of course, the massive METAL platter takes care of that as well as dampenin g vibrations.

For a cassette, maybe I can get ahold of my ex-boss who has a Nakamichi Dra gon and borrow that. Actually I got a buddy alot more local who has a good three head Technics. I know it is a good deck because I sold it to him. (re placed it with a Pioneer CT-F950 which sounded just as good even without ha ving Dolby HX)

Surely you don't beieve this new junk is anywhere near the quality of the b etter vintage stuff. Hint ; if it was, it would be considerably more than a hundred bucks.

Builb me a Dual 1229Q with the most moderne manufaturing techniques but adh ering to the original design, it would ocst at least a grand. Same with old cassettes and actually reel to reels.

No, noting gets better, just cheaper. EVERY advance I have sen in consumer electronics has made it cheaper to build. They make out when it is not chea per to sell. The advent of digital tuners, they are CHEAPER than a TV turre t tuner or even the elcheapo wafer tiners. It would cost more to manufactur e a combo four gang and three gang tandem variable capacitor for a tuner no w then the whole front end costs, and all you have to do is feed it data wh ich comlies with the Phillips standard or something like that.

hat I saw happen to cassette drives and turntables, I don't even want them from the 1980s usually. Give me the 1970s era stuff. the later shit is real ly shit. A stamped capstan flywheel, are you kidding me ? A plastic platter on a turntable, yeah right.

This shit is NOT high fidelity and does not do justice to the format it is getting converted to, NOR EVEN THE SOURCE FROM THE 1950s ! I am amazed at h ow good some of this old stuff sounds, really. (on good equpiment that is)

So, my personal and professional opinion - I disagree. I wouldn't hit a dog in the ass with most of this new junk.

Of course that is a colloquialism. I have no dog, if I did I probably would n't hit it and I wouldn't do it with electronic equipment no matter how shi tty it is.

But that's the saying. I believe it applies.

Reply to
jurb6006

I'm not impressed with Crown or Peavey for that matter. There were several times I was thinking to myself, "Why did they do that?"

I saw the other day the tv show "Undercover Boss" which went undercover at Peavey. Yup, I saw Peavey is still just as bad as they always have been. If anyone gets a chance, check out that episode, it's a riot!

I dunno, Peavey has always been at least functional and cheap. They've never pretended to be otherwise as far as I can see. You get what you pay for.

Tell you what though, the Peavey Classic 30 guitar combo (old version) is one of my favourites, and I'm a crap guitarist, but know when things sound good.

Gareth.

Reply to
Gareth Magennis

I just watched it. It proves one thing - business is business.

From what I can glean they are not publicly traded, so offshoring is an OPTION for them.

Reply to
jurb6006

Ah, now if I could remember where I put the flywheel/turntable of my Garrard Lab A (like:

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I'd weigh it for you!

Mike.

Reply to
Mike

On Monday, February 23, 2015 at 7:40:41 PM UTC-5, snipped-for-privacy@gmail.com wrote in sci.electronics.repair:

I didn't know that public companies didn't have an offshoring option. (if that's what you mean)

Reply to
mogulah

Stockholders can sue the CEO or board if they do nott do everything possibl to maximize profits. The Dodge brrothers sued Ford, literally for making the cars too good and paying the workers too much.

The Dodge brothers won.

So it's not like an actual written law but most people do not want to be sued.

Reply to
jurb6006

Stockholders can sue the CEO or board if they do nott do everything possibl to maximize profits. The Dodge brrothers sued Ford, literally for making the cars too good and paying the workers too much.

The Dodge brothers won.

So it's not like an actual written law but most people do not want to be sued.

Er, that was in 1919. I don't think the same holds true today.

In the UK, shareholders occasionally get a bit miffed when board members get excessive remunerations, or turn out to be incompetent or corrupt, (as a lot of them are), and can organise an Extraordinary General Meeting to try and vote out such Board Members if things are not going to their plan, but that's about the extent of their powers AIUI.

Gareth.

Reply to
Gareth Magennis

Why wouldn't it ? You set a precedent that is it. Unless a higher court has actually made a contradictory ruling since then, it stands as case laws. A t least in this country. (that is one of the reasons there are out of court settlements)

Hell, a whole lot of stuff still stands from 1800, 1863, 1865, 1789 and so on. In fact the creation of the federal reserve just had a centennial last year. Not been changed. Still stands.

Of course there are people who say the Constitution doesn't still stand but they are full of shit. It is not a fluid document, it is written on hemp p aper with primitive ink boiled down in someone's sink or something. Castle law doctrine actually was right, one of the few right htings the supreme co urt has done in a long time. It is based on the letter of the Law, not the interpretation of some Constitutional "scholar" who should have been flunke d out and made to flip burgers.

It stands.

Reply to
jurb6006

There is a similar mechanism here, but over there they might not have the option to just take it to the bench. Over here if you got money you cna sue for anything.

Reply to
jurb6006

Not sure I care who is your "here" and "there", but in the UK we have the concept of "vexatious litigants". There's even a public list here:

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Mike.

Reply to
Mike

Oh boy do we need that here !

Vexacious litigants. What'll they think of next.

Reply to
jurb6006

Oh boy do we need that here !

Vexacious litigants. What'll they think of next.

Hey look, if you wanted to decimate the share price of a company and thereby profit from it (by shorting the shares), you could do well by launching a Vexatious Litigation.

This happened to Gulf Keystone Petroleum recently, for example.

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The court case ran for a few years, cost tens of millions, and those that brought the non existent case eventually had to pay millions in legal costs, because they just had no case whatsoever. It was a punt.

In the meantime, Investors saw their investment totally decimated.

That is not to say that those bringing this bogus litigation may have made many more millions than they lost by having prior knowledge that this case was going to decimate the share price. (Of course they would not make this knowledge publicly available as they would find themselves in jail)

But there are lots of "backers" out there who are prepared to fund these preposterous litigation cases, because the rewards of winning just one far outweigh the risks of losing the other 99. You can win that one you need on a technicality.

And if you are really clever, your backing company can be made insolvent by the costs awarded against it for failing this bogus litigation, so you don't even need to pay them. Then you just start another backing company and have another bash.

I'm in the wrong job.

Gareth.

Reply to
Gareth Magennis

Understood.

One thing alot of people do not know about this country is that members of congress are exempt from all kinds of conflict of interest and insider trad ing regulations. They can, by legislation, make or break a company or indus try and freely trade in it, totally indemnified from any action of the SEC or anyone else.

So I wouldn't be surprised if alot of these suits were vexatious. Politicia ns here are lawyers, so what do you expect ?

There is the ability to countersue for "frivolous lawsuit" but this vexatio us thing seems to hit the nail more on the head, preventing the court syste m from being abused for personal gain.

Reply to
jurb6006

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