Blowing speakers

[naturemara]

i bought a used sony str de 197 and hooked up 2 sets of old speakers which played for a minute or 2 then sparked and blew I do not want to buy new speakers if the receiver is bad. Is there any way to to check the unit with a multimeter at the speaker jacks to make sure it is fine. Thanks to anyone who can help

 

[Guest]

Sounds like the Sony is defective -- you'd have to playing at insane volumes to see sparks, the speaker would just fail if the music was simply too loud.

Your post is not clear as to whether you blew both speakers of a stereo pair or two separate sets of speakers -- either way I'd dump the Sony.

You might try setting your multimeter to AC then DC in the 200 volt range -- any reading over 20 volts, especially with no signal, would confirm something amiss.

 

[naturemara]

Sounds like the Sony is defective -- you'd have to playing at insane volumes to see sparks, the speaker would just fail if the music was simply too loud.

Your post is not clear as to whether you blew both speakers of a stereo pair or two separate sets of speakers -- either way I'd dump the Sony.

You might try setting your multimeter to AC then DC in the 200 volt range -- any reading over 20 volts, especially with no signal, would confirm something amiss.

Thank you that what 20 bucks gets you

 

[Guest]

I wouldn't get too discouraged. I regularly use 25 year old British-built Mission amp that cost about $4.50 in a flea market.

And a Yamaha receiver (from the attempted repair, the previous user had mistaken an indicator bulb burning out as psu failure) also have a perfect 50+ watt NAD receiver -- both found dumped in the street.

Much of this old stuff sounds better than the latest equipment and is built like a tank so I'm surprised that your Sony would fail -- it may be worth checking it out further.

 

[ddawson24]

Speaker outputs are an AC signal but with a multimeter it really isn't going to show you if it's bad or not. It would pretty much show if there is voltage there. You would need an o-scope to really be able to see the wave and what is going on. The easiest test would be to find a cheap speaker for like $5 that you don't care if it blows or not and hook it up and see what happens. More than likely you have a bad receiver but if there was something shorted in the old speakers or they were a weird impedance that could have been the issue too.

 

[americanaudiophile]

If you get any DC at the speaker terminals over .5v with or without a signal there is a problem with the receiver.