I have an old pioneer RX-521 stereo tape deck receiver and need to know how many watts it puts out before I get speakers. I think it is around 150 watts. on the back it says the whole unit uses 380 watts.

 

Get whatever speakers you want, watts doesn't matter and for the most part is a useless measurement.

 

watts does matter if I put speakers that are not strong enough to handle the wattage that the system puts out it could blow them up

 

Unless you are trying to use pc speakers I doubt that will happen.

 

What Stereoguy is trying hard to say in a nice way is that the power figures quoted by Pioneer (and many others) is not a realistic number. It is peak watts and is rarely ever achieved in a normal listening session. Onkyo and Harmaaon-Kardon (and a few others) quote their power in contimuous watts which is a more realistic number. My Onkyo is much louder than a Sony that is "rated" at twice the power.
Alos - most speakers on the market can handle the power output of most amps. Do make sure you get 8 ohm speakers and not 6 or 4 ohm speakers.

 

To add to what Bob said there are also no standards for distortion levels at which those wattage figures are attained. A Curtis Mathis amp might get 100 watts per channel at 1.0% THD (Total Harmonic Distortion) while a Krell amp might get the same wattage at .0000001% THD. Both are truley putting out 100 watts per channel, but the 'loudness', clairity, quality, price and weight of both units will be extremely different.

IMHO wattage numbers are basicly meaningless until you get into gear that costs $1-2k or more. Then you can typically start to trust them more, but they are still not a solid benchmark.

 

Can we get a sticky on watts and what they should mean to someo0ne shopping for an amp/receiver?