How do amplifiers improve sound quality?

[Zedly]

I have come across many articles and videos that discuss the benefits of adding an external amplifier to an A/V receiver. Often they mention improvements in clarity, dynamics, soundstage, "crispness", detail, etc., even at the same listening level. Which of these improvements can actually be attributed to the increased power from the amplifier, and how does the amplifier contribute to that (e.g. "more power causes the speaker cone to change direction on a dime, resulting in a snappier sound" - no idea if that is true, but that is the sort of thing I have come across). What are the real improvements that can be expected from using an external amplifier?

 

[Jimbob54]

You've lost me there. Adding an amp to an amp?

 

[Zedly]

I'm talking about using the pre-outs from an A/V receiver and connecting them to the inputs of an external amplifier. Many people suggest that instead of using the internal amplifiers on the receiver.

 

[suttondesign]

Without knowing the quality of the line level signal, it's not possible to state definitively, but it's a fair assumption that most receivers won't do too much damage to an input except mechanical hum from crummy transformers. If that is not an issue, then I believe that a superlative outboard amplifier would be better than most a/v amplifiers. However, given the size and heat of a/v receivers, it would be better to switch into a dedicated a/v processor in lieu of a full-on receiver.

 

[Koeitje]

I think its mostly just a lack of power. But it really depends on your needs and your speakers. If you have inefficient speakers most AVRs wont get them to reference spl.

 

[Prana Ferox]

improvements in clarity, dynamics, soundstage, "crispness", detail, etc ... more power causes the speaker cone to change direction on a dime, resulting in a snappier sound

Most of this is the audiophile standard "My setup now costs more, surely it sounds better" nonsense. Also, that's flat out not what more power does. What they're describing is damping factor, which is a non-issue with solid state amps and only barely relevant with tubes.

Usually an AVR has a lot of amp channels all fighting, for power supply and heat rejection capacity, with each other and with all the A/V processing circuitry. An external amp can have significantly higher current delivery capacity, and be built for more power delivery over time. The degree to which those are true, and certainly the degree to which it's audible, depends on the AVR, amp, load, your finger on the volume knob, etc.

 

[Asylum Seeker]

An amplifier should do no more than...wait for it...Amplify! It should be a wire with gain, adding to and taking away nothing from the frequency, THD, crosstalk and phase of the input signal.

 

[NTomokawa]

Start here. But it boils down to two things: Power and impedance bridging.

A good amp should act like "wire with gain". Indeed many of the Chi-Fi stuff Amir has measured do just that.

 

[Chrispy]

Sounds like you've been listening to ampliphiles. Aside from advantages in real aspects like more power, or lower impedance handling, or results like higher spl or overhead....

 

[Zedly]

Thanks for the input. Here is an example of the kind of thing I've been coming across. Perhaps the integrated amps have been underpowering the systems.

 

[NTomokawa]

Sighted listening and expectation bias...

 

[Chrispy]

How are you determining "under powered"...a misused phrase at best.