old power amp output impedance missing

Lestraveled

Joined May 19, 2014
1,946
The Electrician
You are entirely correct. You have made your point very well. My point is, the OP wanted to know what the output LOAD impedance that his amp was rate for. Doing the test you and Mr.Chips prescribed will not tell him what the optimal output load impedance is. Sure, it will tell him what the amplifier output impedance is, but a number like .14 ohms will do him no good.

I admit that I should have been clearer when I said that,"the test would not work on solid state amps". A more truer statement would be, " This test will only tell you what the optimal load impedance is on a transformer type amplifier. It will not tell you what the optimal load impedance is on a solid state amplifier."
 
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My point is, the OP wanted to know what the output LOAD impedance that his amp was rate for.
That's not what he said he wanted to know.

In post #1, he said "is there a way to find out the output impedance from a power amp?"

In post #7, he said "is there a way to measure with a multi meter the output impedance from a power amplifier?"

What he said he wanted to know was the output impedance of the amplifier, and the early responders, especially Mr. Chips, were explaining to him how to determine it.

The OP no doubt assumed that knowing the output impedance of the amplifier would help him determine the appropriate speaker impedance.

Doing the test you and Mr.Chips prescribed will not tell him what the optimal output load impedance is. Sure, it will tell him what the amplifier output impedance is, but a number like .14 ohms will do him no good.
The good it does him is that it would tell him he has a low output impedance amplifier, and any typical speaker impedance will be ok.

I admit that I should have been clearer when I said that,"the test would not work on solid state amps". A more truer statement would be, " This test will only tell you what the optimal load impedance is on a transformer type amplifier. It will not tell you what the optimal load impedance is on a solid state amplifier."
The optimal speaker impedance to be used with a tube amp is not necessarily the same as the output impedance of the amp. Using a higher impedance speaker with a lower impedance tube amp can give a higher damping factor, which might be what the speaker designer wanted. With solid state amps, you get a high damping factor for all speaker impedances.

There isn't usually a distinct "optimal" load impedance for a solid state amplifier. Knowing that it's solid state means he can use a 4 ohm or 8 ohm or even 16 ohm speaker without any significant performance degradation other than available power delivered to the speaker.

Good solid state amps are usually protected against damage from overdriving a load, even shorts. The speakers might get damaged but probably not a good quality amp.
 

Lestraveled

Joined May 19, 2014
1,946
now i want to use it but im afraid the impedance from both doenst match....

is there a way to find out the output impedance from a power amp?

cheers
i dont really NEED to know... i just dont what blow it up if i connect with the worng impedance... but yeah... if you say the solid state doenst matter than okay... but i dont know if the thing is a solid state... but must be somehow
The OP is not asking to find out what the real output impedance of his amplifier is. He simply wants to know what impedance his speaker should be in order to not blow up his amp.

I think we should listen to what the OP is asking for, before, we run off on a technical witch hunt to provide information that they didn't ask for.

Sure, simple questions spawn interesting discussions, but lets answer the OPs question before we launch into the ozone.
 
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