Amps (1 Viewer)

[Denny Oubidoux]

Not guitar amps, the ones you use for your stereo speakers, listening to music.

Mine has started making a dreadful buzzing noise that gets louder the longer it goes on. The buzzing isn't in the speakers, its just coming from the amp itself. Is this something that can generally be fixed up or is it a sign the thing is on it's last legs? I have it 10 years.

Between this and the noise my computer makes it's like living in some nightmare world where tinnitus has escaped from the confines of skulls into the electricity network.

 

[hydromancer]

It will burn out anytime soon posibly even explode.

 

[GO]

Its fucked.Be cheaper to get another one o Adverts

 

[Denny Oubidoux]

bollox

 

[GO]

What one is it?

Is it stereo or surround?

 

[Denny Oubidoux]

Just a plain old stereo one. The tweeter in one my speakers blew a few years ago and I had to pay about €250 to get it fixed and the repair guy told me that an amp that wasn't powerful enough for the speakers could do that. I didn't bother checking this shit out then but I suppose now is the time if I have to replace it.

 

[GO]

Yeah..clipping an underpowered amp can wreck tweeters.

You'll pick up a solid replacement stereo amp for less than getting one repaired.You need to make sure you get a good powerful one though so you don't need to drive it hard

 

[Denny Oubidoux]

So the more watts the better? Yer man Paul White from sound on sound says of my speakers:

A power amplifier of between 75 watts and 100 watts per channel should suffice. However, the amplifier should be capable of working down to 3(omega), because most speakers drop below their rated impedance (in this case, 4(omega)) at some point.

The amp i have is 85 watts per channel, specs say

85 watts per channel into 4 ohms

Are ohms the same as omega? Might the blown tweeter be a result of the amp not working down to 3(omega)? Whatever that means...

 

[GO]

Hmmm..3 ohms is a bigger draw than 4....but if the amp and speakers both say 4....then I'd imagine its all good.

Unless the speakers are really drawing 3..then that'd fuck them up if left playing long enough

The amount of watts you really need depends on the sensitivity of the speakers..but more watts will drive all speakers..while less watts will only drive certain ones...

I'm not an engineer though..but I read alot about hifi

 

[Denny Oubidoux]

Thanks GO

 

[Space]

have to say I've never heard of this idea that speakers fall below their rated impedance. I've a set of forty year old speakers that still read the 8 Ohm they're rated at. just match the ratings and all is good.

 

[ann post]

Was wondering about that. Any chance they were 6ohms in series to begin with and one is shorted in series?

 

[GO]

have to say I've never heard of this idea that speakers fall below their rated impedance. I've a set of forty year old speakers that still read the 8 Ohm they're rated at. just match the ratings and all is good.

I was wondering about that myself.I never heard of it either.

But I havent heard of a lot of things

 

[Space]

Was wondering about that. Any chance they were 6ohms in series to begin with and one is shorted in series?

Two hifi
speakers wired in series? so in this scenario would the power amp be bridged mono giving you a 2 ohm output impedance or would both speakers have been wired to either the left or right amplifier? Even if the speakers had dropped a bit they should still be close enough to the rated impedance so really barking up the wrong tree with blaming the speakers for the damaged amp in this case in my opinion. In this case I'd put money on amp parts wearing out and needing replacing.
Probably worth checking all your leads first and isolating the problem to left or right channel etc..

 

[ann post]

Two hifi
speakers wired in series? so in this scenario would the power amp be bridged mono giving you a 2 ohm output impedance or would both speakers have been wired to either the left or right amplifier?

was mostly just throwing theories in the air - but if for example the left had a driver and tweeter in one enclosure with a short between driver and tweeter, then you'd be able to get a 3ohm reading off a 6ohm speaker enclosure. they'd want to be 3ohm to start with, which i've never heard of.

 

[Space]

Sure keep firing out random theories so.

 

[ann post]

what is so random about trying to figure out why 3ohms is reading?

 

[Space]

Who was reading 3 Ohm?

 

[Denny Oubidoux]

On the back of the speakers it says "Nominal impedance: 4ohms, Amplifier power: 50 - 100 RMS watts".

I should be alright with an amp that says "2x 150watts/4 ohm, 2x 85 watts/8 ohm" should I? Or am I overdoing the watts?

 

[Space]

You'll be alright but don't turn up the amp to full. Not that you ever would. The extra bit of power will mean you won't be distorting signal with the amp so safer all round.