I just blown up two amps in one week-end (1 Viewer)

[PhillJones]

AMEX = American Express

The amp has one of those remote controllable electronic volume nobs, you know the ones that aren't just a pot and have no stop at the end and if you turn it when the Amps not powered on, it doesn't do anything. It came on at 45, whatever that means, so I turned it way down.

 

[Andrew*Be]

A dealer should never bully you like that. I would never go back to them ever and I would certainly never recommend them. Where do they get off with this "holier than thou" attitude, you're the one with the money going to spend it on their expensive equipment. They should be rolling out the red carpet for you.

Have you listened the the Anthem amps? Like the PVA-5, PVA-7, or MCA-5? Extremely well made, affordable, and yes they do have fuses that you can replace!! The newer Anthem amps (the Statement series ones) actually have a fuseless design which allows you to reset them like a circuit breaker.

--Andrew

 

[Charlie C]

amex, doh! I see! ok, thought it was a new transport of some sort. thanks


"It came on at 45, whatever that means, so I turned it way down."

I just hope you turned LEFT. my volume goes from low low volume at -74 to 0 being full blast.
Im not calling you stupid ignorant or anything for that matter but to blow 2 rotel receivers in an instant does hint at some user fault. again, im not accusing you of anything because I have nothing to gain/lose from what you do but I would hope that this problem gets resolved ASAP for you so you may enjoy your setup.

 

[Yogi]

Its a sign that you are turning into an audiophile, when you think AMEX is a new transport of some sort. J/K

 

[Charlie C]

hey now yogi, it does help TRANSTPORT expensive stuff from the store to your home... but yeah I should known. even googled AMEX and all I got was american express. just didnt seem right. thought he hooked up a new transport to a power amp without any resistance between, that would surely blow a new amp.

 

[Yogi]

Could you use a hair wig or something and go disguised? Or may be grow a goatee or something? Or since MA is such a small state you could always drive down to CT and shop for your Rotel. I used to drive down to NY state after 8PM when I got really desperate for beer.

 

[PhillJones]

I actually found the short and fixed it. A bit of metal burr between the contacts on the speakers. I should have looked more closely.

Maybe, it's different if they're permanently shorted as apposed to just touching briefly, I don't know.

The system as it was was just the reciever, 2 Tannoy floorstanders and some cable-talk 4.1 wire I brought with me from the UK, I was using the radio receiver to test it.

I spoke to Rotel and they said that shorting out an AV reciever could well make it explode and that they aren't well protected. IIRC, he said 'you don't have as much luxury in a receiver design' or something that made just as little sence.

It seems that the line from Rotel and the dealer is that if you short out the terminals any receiver, or perhaps any high-end receiver will burn. So don't short them out, like an idiot.


I'm going to get a multimeter and test the impedences at the amp terminals next time before I power up whichever amp I eventually get. The guy at Rotel said I should see about 4Ohms against a multimeter.

 

[Charlie C]

cool, hope it all works out.

 

[Yogi]

That made no sense at all. Like someone earlier pointed out, even cheap HTIB have protection against something like that. Shame on Rotel for such a ludicrous response.

 

[Lee Distad]

Slightly off topic, but it is not unknown for some esoteric 2-channel integrateds to have NO protection circuitry, on the pretense of having the cleanest possible signal path with no dipsy doodles to create distortion (do you believe that!?).

I've been racking my brains for a specific brand that is famous for this which is on the tip of my tongue, but I'm having a brain fart, and it's not coming. If I remember, I will post a link later.

 

[Lee Distad]

Vasant, built by Kim Song, that's who I was thinking of!

http://www.soundstage.com/revequip/vasantk_ga120s.htm[/url]

Note how the reviewer takes pains to note that shorting the speaker terminals would be a bad, bad thing.

 

[Nick Laho]

I have never tried a Rotel amp, but my NAD C370 shut itself down just fine when I had the speaker wire accidentally touching eachother. I even turned it on a few times as I didn't know what was wrong, it shut itself off as I turned the volume up a little. I uncrossed the wire and all was fine. This perticular amp seems to have terrible protection, or something is wrong with your speakers or something.

 

[Andy_Steb]

Complete BS the $2000 RMB 1095 has heat and short protection circuits.

Rotel may have a serious problem with the RSX-1056 and your dealer needs to tell them so they can fix it. not give you a line of BS to defend them.

 

[DavidLW]

Don't AMEX offer a no question ask protection policy for the replacement for anything bought with their card? I kind of remember seeing commercials of consumers dropping, losing, stolen, dog chewing up and kids breaking items bought with the card and AMEX will replace it. This was a while back and I'm not sure if it's still being offered.

A lot of "High End" amps have protection in the form of thermal sensors on the output transitors. The electronic parts used are built to withstand a short for the time it takes for the thermal sensor to kick in. This way no "degrading" protection circuit is placed in line with the output voltage. I think it was Mark Levinson that claimed that you could do minor arc welding across the terminals of one of his amp. :frowning:

 

[Michael R Price]

Short circuit protection does not hurt sound quality. If you are really anal about the signal path, you can use relays. Additionally, some types of amplifiers (mainly: Class A) have an inherent current limiting which prevents damage in the event of a short.

The damage may smell bad but it usually doesn't cost much to repair a blown amplifier. I shorted out and blew one channel of my cheap Audiosource amp, and I needed to replace two power transistors (fairly typical) costing a total of $6. Works good as new.

I think I've shorted the output of my big, unprotected DIY amplifiers a couple of times and they didn't mind.

 

[PhillJones]

This sort of ties in with what the Rotel guy said. He said that it had no fuses or protection circuit but had thermal protection BUT he said that it was less effective protection than a protection circuit.

Logically, this suggests that the circuits in the Rotel RSX-1056 are of insufficient quality to withstand a short until the thermal sensors kick in. The question is, does it really come down to a choice between sound quality and protection? The rotel amp did sound better than anything else I auditioned.

What do you guys think?

 

[Dan J S]

Well, I think you should completely forget about buying that receiver/amplifier regardless of how good it sounded. There are definitely other options that won't have this problem and will sound just as good. How many recievers did you audition?

 

[Kevin T]

sounds like bullshite to me. my plinius sa-102 has a protection circuit in it and i've always considered it to be "high-end". i'm not sure if you have a hard-on for rotel, but i kinda dig my denon avr-3805 receiver. you might wanna check out some of denon's offerings. granted, it only gets used for home theater and not music, but for home theater, it performs like a champ. just an idea.

kevin t

 

[PhillJones]

You're right, I shall stop dwelling on it.

I'm just fed up because I've been planning this for months and went all the way from from finding dealers to getting it home.

 

[Yogi]

Well if you dont mind driving down to Hartford, which would be about 2hrs away from you, on a weekend you could still buy Rotel. Roberts AV is a very nice and professional dealer that should get you what you want.