Power Amp Q for Techies:

[sloom]

Greetings,
I'm looking at a Crest V1500 power amp. Now there's a spec on it in it's .pdf that reads: "20Hz- 20kHz, -3dB @ 165kHz".

Where does 165kHz fit into specs for an amplifier? Cearly this can't have to do with audible frequency response? The number is in two separate pdf files for the amp. Anyone know what this means?

Thanks!

[wilkee]

Presumably its frequency response from 20 - 20 k must be basically flat and it is then down by 3db at 165khz.

I assume that this is at low output levels as I would not want a P.A. amplifier that coud stick out half its output at such high frequencies.
Shows a good slew rate though.

Tony

[sloom]

I think this must be true. 165kHz is clearly irrelevant in 'real' terms, and I think the spec is there just for information sake. Just because you can't hear beyond 20kHz doesn't mean the thing isn't somehow functioning way up in that ultra-high range.

And I can't see a poweramp intended for audio not being optimized for sound for humans...

[BadAE]

This may help you understand the spec.

[sloom]

I'll have a look at that tonight. Thanks, BadAE.

[Harvey Gerst]

Originally Posted by sloom

I think this must be true. 165kHz is clearly irrelevant in 'real' terms, and I think the spec is there just for information sake. Just because you can't hear beyond 20kHz doesn't mean the thing isn't somehow functioning way up in that ultra-high range.

And I can't see a poweramp intended for audio not being optimized for sound for humans...

It's NOT an "irrelevant" spec. It's important to understand how the amplifier responds to fast rising signals, like a synth square wave. Cut the amp off at 20 KHz, and you'll lose a lot of the sound, turning the square wave into a nicely rounded sine wave.

[wilkee]

Originally Posted by Harvey Gerst

It's NOT an "irrelevant" spec. It's important to understand how the amplifier responds to fast rising signals, like a synth square wave. Cut the amp off at 20 KHz, and you'll lose a lot of the sound, turning the square wave into a nicely rounded sine wave.

Quad made a lot of money selling amps around the world that were strictly limited 20-20k. AFAIK the jury is still out on this one.

Tony