Amplification basics (1 Viewer)

[Rock M]

Couple of questions on amplification.

1)Is amplification additive? If one wired the speaker outputs (not preamp RCA outs) to an amplifier, how would the amplification be calculated. Ex, receiver outputs 80wpc (all channels driven) into an amp the outputs 100wpc. Is this connection even possible? If so, what is the result?

2)If one had an audio source, something that just had speaker outputs (no preamp outputs). Can you hookup a car stereo amp to get more power. Maybe I should ask the difference between home audio amp (like that sub amp at PartsExpress) and those car stereo plate amps.

Thanks in advance,

Rock

 

[Cees Alons]

Rock,

No you cannot multiply amplification by putting amps in series.

Each amp can only output its max power.

The input of an amp is mainly voltage determined, it won't suck much current from the previous stage. And in fact, a power amp does not amplify the voltage that much, it only has the "power" to maintain that voltage even if a high current has to be delivered (power = voltage times current).

This partly answers your second question too. No, it cannot be done.

The main difference between a "home" amplifier and a car amplifier is the ac/dc voltage it takes to work. Car amplifiers usually need 12-14V dc, while "home" amplifiers have circuits to enable it to work from 110V ac (if you live in the States).

Cees

 

[Vince Maskeeper]

2)If one had an audio source, something that just had speaker outputs (no preamp outputs). Can you hookup a car stereo amp to get more power. Maybe I should ask the difference between home audio amp (like that sub amp at PartsExpress) and those car stereo plate amps.

Well- you could- however I don't know if you'd want to bother.

They do make boxes which will take a speaker output and transform the signal level back down to line level for use with amplifier inputs (or other similar inputs like cassette decks or receivers). You could procure one of these boxes which would take the speaker level you feed it and make it able to be connected to a car audio amplifier.

However- you will certainly degrade signal quality by making this transformation. What's more, you are trusting a passive piece of electronics to serve a very important step- if it fails at its job- you could easily feed too much signal to the amplifer, clip the input, distort the signal and blow any speakers connected as well as the amplifier itself.

The main difference between the two amp types is the AC/DC issue- and in my estimation the wattage figures on car stereo products are the result of some generous math in the transition. Some people do use old car stereo amps in their HT system- but this is somewhat non-ideal. I would suggest strongly that you use a real amplifer designed for the purpose you're using it for.

-Vince

 

[Rock M]

Thanks for the info I appreciate it.

Rock