72 replies to this topic

[mk1982]

ok we all know that power is important in selecting an amplifier, the more the better - less distortion and more head room .. great !

if true rms power and input sensitivity are the same, what else will make an expensive amplifier truely sound better than a cheapie ?

i'm wonder what you all noticed when upgrading your previous amp to a newer more expensive amp of the same power rating ?

at the same volume, same crossover settings, could a 2x50 zapco/pg/xtant sound better than a 4x50 (running on 2 channels) jaycar response ? i understand that the higher end amps are often under-rated .. for example the jaycar amp could be measured at 14.x volts while the xtant/zapco/tru at 12 ..

anyway u get the idea ..

we were just talking about cables and a lot of articles have been posted suggesting that build quality is more important in RCAs so they have a good life span and the speaker cables - well .. there aint much difference between 'standard' and 'esoteric' .. (hope that's right)

i hope that the same conclusion comes from amplifiers ..

i'm sure so many of u have upgraded their amplifiers while possibly keeping the power the same or possibly downgrading the power while 'upgrading' the brand ?

it's so tempting to buy a high-end amp but i wonder if it's really worth the money .. eg. it's said that THDs below a certain percentage are indistinguishable (sp?) .. perhaps someone has borrowed their mate's 2x150 response amp and plugged that into their system to compare with their 2x75w audison/alpine/pg and has noticed a difference ..

from my limited experience i believe measured rms power is the most important in deciding sound quality, but have no experience to back this up. more power eg. 150w will provide less distortion and more headroom than a more expensive (pg,audison,alpine,xtant,whatever) 2x80 or 2x50 .. ??

tough questions i know but i'd rather hear it from here than a sales person what are your views on this ????

i know that a $329 2x150w response is a powerful amp, but it's considered to be very AVERAGE in terms of SQ. the power's there, all 150w of it .. but the SQ might not be .. WHERE DID IT GO ? and can you hear the difference ? (some readers who have read about the Richard Clark challenge may be able to provide some further interesting input here .. sure the specs of a higher end may be better (thd, slew, seperation), but is the difference really audible ?

[Mike_McT]

Interms of sound quality, I think many amplofiers have sneaky ways of publishing their specs:
eg. frequency response on a full-range amplifier is usually 20-20kHz, but many companies can write this by documenting a [-3dB,+0dB] rating after it. This means that the amp is only capable of putting half the SPL out at these certain frequencies (usually bottom end)

Secondly, a lot of amp don't publish their damping factor these days ie. the amp could pump out midbass really well, but the sound is "laggy" or muddy when played in certain situations..

Anyway thats my two cents

[audible]

There can be a big difference in soud quality of amplifiers. Some time ago, my alpine 3527 4 channel amp, that runs my front tweets and rear fills broke down, so while it was out of the car getting fixxed, I thru in a jaycar 4 x 50 watter blue amp.

That amp came out the next day. it sounded dreadful. Sibulance, narrower sound stage, noise, you name it, it was bad.

I found it better to not have any music in my car at all rather than listen to that crap.

And I sold the jaycar amp which pretty much covered the repair bill on the alpine!

[Blackrazor]

mk1982 said:

but is the difference really audible ?

In my experience and (fairly well educated) opinion, not if all things are equal, and not in daily use... there are very certain situations where the amps construction may make a difference (driving into Quad ESL's for instance) but in general use, no, hence why RC is happy enough to offer $10k to anyone who can spot the difference between amps when all other variables are removed...

But there are plenty of people, both here, and around the world, who trust in their ears over anything else, flawed as that logic may be, and they truly beleive they can hear a difference...

In short, if you beleive in testing and scientific methodology, and understand the principles behind the RC challenge, then no, you dont beleive in amp sound... on the other hand, if you beleive in the infallibility of the human ear, and beleive that the ear can hear things that man, with all of his advanced science (some of which was used to record the source in the first place), cannot pick up, or if you refuse to accept scientific tests as fact, then yes, you'll probably beleive in amp sound...

Because as we all know, to your eyes the world looks flat, so it must be flat, and damn the scientific proof to the contrary :wink:

However, even if SQ is not a consideration, there are plenty of reasons to buy high end amps... build quality, reliability, appreciation of nice things... i'm a salesman, and i love nice things (mmm, Zapco/TRU/McIntosh/Genesis) and i love helping other people get nice things... but when they buy nice amps i make them aware they arent buying 'better SQ', what they ARE buying is more power(normally), better aesthetics, and superb build quality, all of which are just as much of a reason to plonk out some extra cash...

[mk1982]

audible, interesting as the alpine u mentioned appears to be 4x30wrms

blackrazor, as a salesperson thanks for ur honesty. i agree that build quality and aesthetics are definately there in the higher end amps and often their features (perhaps input sensitivity) and technology, quality of materials is better and is obviously worth the $$$ for many. however what would u consider to be some cheaper brands that play almost just as well as a zapco/tru/mcintosh thru to good speakers (boston, focal, mbq, diamond) etc ?

do you get jaycar response amps over there blackrazor and have u had time to plug one in and have a listen ? i'd also be interested to hear how the huge power (2x150) and therefore less distortion and more headroom may compensate for the lacking features ? user 'audible' obviously did not especially like the 4x50wrms response compared with the 4x30wrms alpine !!!! im wondering if other users had a similar result ?

[mk1982]

by the way, has anyone ever come across GOOD Jaycar amp specs including perhaps a birthsheet, response graphs etc ???

[Blackrazor]

mk1982 said:

do you get jaycar response amps over there blackrazor and have u had time to plug one in and have a listen ?

No sir, we do not...

As a general rule, buy an amp on reliability and power, but be aware that for most people, 20-30w of good clean power is all they need, and anything above that is just headroom on a daily basis... also be aware that it takes 10x the power to get double the perceivable volume, so the difference between a 75w and a 150w amp may not be as huge as you think, you're talking a theoretical 3dB of volume gain, which is decent but certainly not earth shattering...

Heres some tips for buying amps :
1) Figure out how much power you need to drive your speakers... for daily playback in a high-passed system, 95% of people wont need more than 50w per speaker, but extra is always nice.
2) How important is reliability, backup an support, and construction to you? If they are, then you might be better going for a 75w name quality brand rather than a 120w non-name brand (there are exceptions of course)
3) Are aesthetics important? If so, name brand.

Always buy your amp to suit your speakers, not the other way around. But most importantly, above 50w per channel for speakers, you are unlikely to use the extra power on many occasions, so rather than coughing extra for a 200w amp that you'll use the extra power once in a blue moon, put your money down on something with less power, that will give you flawless, troublefree operation for its lifetime...

[gooki]

My thoughts on what the most significant differences between cheap as chips amps and high end audiophile amps.

1) Power supply - a stable power supply system provides a constant accurate audio reproduction.

2) Crossover components (if you use them).

3) Stero seperation - dual monoblocks are going to have a much better stero seperation than a standard 2 channel.

4) Quality of components and amp design - which results in better noise reduction and a more pure sound.

[Blackrazor]

gooki said:

3) Stero seperation - dual monoblocks are going to have a much better stero seperation than a standard 2 channel.

I dont think theres even slightly as much difference between the two as people make out, after all 60dB of seperation is all you need for it to be unnoticable... but then again, monoblocks are nice, and its wanky to tell people you have near-infinite stereo seperation :wink:

[gooki]

where's you get the 60db figure from? I thought it was at that level the signal could be precived as stero not the auidable limit.

PS turn on MSN I had a favour to ask.

[Blackrazor]

gooki said:

where's you get the 60db figure from? I thought it was at that level the signal could be precived as stero not the auidable limit

60dB (give or take a couple dB) is the max stereo seperation that will provide an audible benefit on music... 90dB wont sound sound any better on everyday music than 60dB will, 50dB will be audibly worse however.

Its one of those figures that high end amp companies like to quote (and with good reason, it takes some very well thought out and well designed construction to get high levels of stereo seperation), but beyond a point it is inaudible in real world applications and can be proven to be so...

Having high stereo seperation is usually a sign of a good amp however

[Marlin]

Wouldn't the quality of an amp come down to its ability to reproduce the signal as exactly as possible at a higher voltage? I find it had to believe that a Zapco or Tru tech amp is not going to be vastly superior to a jaycar or sony at this.

[Winno]

Blackrazor, don't make me snatch that soapbox from under you

[APS]

I dont mean to rain on anyones parade or get into an argument, i am sure we all have educated opinions on certain issues and things in this being the difference that a different grade amplifier can make your sound.

Despite what is being discussed here previous to my post there is no way in this world that a Jaycar amp can have the same output characteristics as some of the more reputable brands.

Basically a more expensive amplifier uses better components has a better build quality, and also has higher signal to noise ratio, damping factor and stereo separation. But what is also important is the input filtering stages and output filtering stages which determine how the input signal will be on the output stage ie. speakers or subwoofers.

The cheaper end amplifiers use cheaper components and less of them so although the output signal measured on a CRO might look similar to an amp of higher quality have you considered the actual signal purity that the amp delivers? What about its noise rejection capabilities? What about the slope on the crossover frequencies?

I agree that looking at the output signal on measuring equipment such as a CRO from a cheap ass amp and an expensive amp yields no great differences as the output is a pure sinewave, but have you considered the way an amp actually sounds to an ear? I agree also that peoples ears are not the same and what sounds good to me may sound bad to you, then why is it that manufacturers build amps worth thousands of dollars. Yes they do make the same power as your average joblow monoblock, but why is it that when the amplifiers get rated, they get rated by being installed in a car or a certain type of environment and then they get ear tested after they have been on the bench to see whether they can make their claimed RMS value?

So sorry to rain on your parade Blackrazor but i am an electronics engineer by trade and i can tell you when i test amps on benches they all have similar output charactristics on my test bench as you have stated and you are correct to an extent. But you are completely WRONG when you tell people that a cheap amp sounds the same theoretically as a more expensive amp. The 3db increase in sound theoretically is perceived as doubling the volume of a certain tone or music, but whether our ears are sensitive enough is what determines whether we hear that difference not the 10x as you stated.

Also real world listening tests do speak for themselves and there is crap load of difference the way amps made by certain manufacturers sound.

[Marlin]

Has anyone considered that music is not a sine wave and measured how a cheap amp reproduces it compared to a expensive amp as oppossed to a pure sine wave?