[Tunes in Toronto]

Wouldn't it be excellent to start a discussion on how best to decide which amp / preamp to purchase.

I've been reading threads for weeks and seeing one amp recommended and another and another.

I need to pull the trigger, but besides THD and Watts per channel I don't really know what other factors I should be looking at.


I think that it is time for me to sit down and compare spec to spec for myself.


Anyone out there like to start this off. How about a list of the factors you would use to decide


Gord

 

[MichaelJHuman]

Seems there's plenty of threads on both amps and pre pros

If it were me, I would probably buy an Emotiva 3-channel amp paired with a receiver whose features met my needs, and power the surrounds from said receiver.

 

[Tunes in Toronto]

If you were to compare spec against spec. What would you look at besides THD & Watts per channel? Or would you just go with a name that you a comfortable with?

 

[MichaelJHuman]

I hate to go as far as saying specs are useless. But let's look at some reasons why they are not as useful as one could wish for.


Power specs are not measured the same way, especially for receivers. For external amps measured with all channels driven, they might be more useful though.


THD+N specs are not the most useful specs from what I can tell. Some claim anything below %1 THD is inaudible. I am not 100% sure about that. But is difference between .05 and .1 meaningful? Seems hard to believe it would be.


And of course people will claim one amp sounds better than another, and specs seem to have little to do with that. So what's up with that? I have no clue, it's a mystery.


For preprocessors, they seem to measure with VERY low levels of distortion and are ruler flat, at least when no EQ processing is involved. So why does one sound better than another? Once again, I have no clue.

 

[DougWinsor]

First look at your speakers you are planning on using and then select a group of amps that can properly drive the speaker load.

 

[Tunes in Toronto]

Well, if specs aren't the answer and I can't listen to the amps with my speakers. I guess I'm back to reading reviews and peoples recommendations on what they liked the sound of

 

[DougWinsor]



Quote:
Well, if specs aren't the answer and I can't listen to the amps with my speakers. I guess I'm back to reading reviews and peoples recommendations on what they liked the sound of

Don't worry about how an amp sounds, if you have two amps that can properly drive the speaker you will not be able to hear a difference. Many double blind tests have confirmed this.


What is your price range?

 

[Tunes in Toronto]



Quote:
Originally Posted by DougWinsor /forum/post/15520117


First look at your speakers you are planning on using and then select a group of amps that can properly drive the speaker load.

Your linc to the forum was interesting. Do you know of one for 2 channel audi to lists the Amps in a comparison spread sheet


Gord

 

[TPnBobcats]

Look an amp is a functional unit. It is supposed to take an incoming signal and reproduce it at a higher power level. If you are hearing "adjectives" from the amp, then it is doing something wrong or is defective.


The other basic fact, is that you need twice the power to hear a noticeable difference. So anything less is pretty much no difference. IE. 120 wpc is essentially the same as 150 wpc. For that 120 wpc amp, you'd need to go to 250 wpc before you can hear a 3 db difference (the minimum audible) and 500 wpc before you'd hear a 6 db diff.


About the only time you really need to worry about an amp is if you have low resistance, low efficiency speakers. That translates out to 4 ohm or less and something less that a 90db efficiency (I think). Speakers like that are going to take something more robust than your typical AVR amps and benefit more from additional power than more efficient speakers.


So as long as you are trying to decide between reputable manufactures, buy for looks and price. Most of the "technical" differences are at best meaningless.