Audio Amplifier frequency analysis

  • Thread starter GD.Boss
  • Start date
Could anyone explain how to analize an Audio Amplifier so it can have good sound output.

Thank you in advance


Science Advisor
Hi, and welcome. Where are you?

Perhaps you could explain a bit more about what you are thinking of doing.

Are you going to buy an amplifier and need to know how to select a good one?

If you are designing an amplifier, I guess you would already know how to test it.
Take the amplifier in both hands and lift it up. Is it heavy?


Science Advisor
Gold Member
What sounds good to you and what sounds good to me could quite possibly be 2 different things, so, no I cannot help you.
Could anyone explain how to analize an Audio Amplifier so it can have good sound output.

Thank you in advance
If you are an Engineer designing an audio amplifier circuit please read the following:

For the audio amplifier to have good sound output it should have the ability to process different frequency components in the audio signal using separate filters. Different frequency components are best reproduced by different types of speakers. So it is necessary to make sure the amplifier has woofer to reproduce low frequency sounds and tweeter to produce high frequency sound. As the number of channels in the audio signal increase you will get a more realistic hearing experience. If the amplifier produces a phase shift for the audio signal then the frequency Vs phase shift curve should be linear. If not phase distortion will occur in the output signal.

If you are a customer buying an audio amplifier please read the following:

Just buy the amplifier which produces music pleasing to your ears. Mostly the audio amplifier which satisfies all the criteria in the previous paragraph technically will have high fidelity and it will produce music that will please most people.
Some audiophiles claim that a vacuum tube amplifier is better than a transistor amplifier, in part because the pentode or tetrode (vacuum tube) output is a very high impedance output, and the speaker cone is more compliant than with a voltage source (transistor) output. The back emf developed by a moving speaker cone is shorted out by an amplifier with a voltage output. A voltage output makes the speaker cone very stiff (low compliance). In my old vacuum tube amplifier, the (now rare) Acrosound ultralinear TO-330 output (push-pull) transformer weighed over 15 pounds. See
Bob S

[added] The Acro TO-330 weighs about 15 pounds per channel, or about 30 pounds for stereo.
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