• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

Why do different amps sound so different?

S

ssv1761982

New Member
Sorry for the long winded question. I have been trying to figure out how to ask this for a while. I haven't got much experience with many amps but here is what I found over the years.

1984 I bought an HK 580i. It seemed to play anything. The bass was deep and the mids & highs were clean and clear.

1994 ish I bought a Yamaha RX 550. It may be a little better on the mids and highs and vocals but just seems to lack in the bass department. The bass is there but it is just not as deep like the HK was.

Recently my son brought over an HK AVR 125. It is different yet. Deeper bass than the Yamaha but overall not as clear on vocals.

We also have an HTR-5940 Yamaha and it is kind of lacking in sound quality compared to the others.

This is all using same Genesis 210 speakers the I bought when I originally got the HK 580i.
 
Register to hide this ad
Because some are better than others. Or more expensive. Or come from a different era. Or got favorable reviews in a mass-market publication.
 
Thats a good question. There are those (some on AK) that will tell you that all amps sound alike. I'm not in that camp, as they all seem to sound somewhat different to me. I know that years ago Bob Carver used to claim that each amp has a signature "transfer function" and that that was what gave each amp its "sonic character" and it seems that he designed to achieve a certain said "transfer function". I don't recall exactly what that measurement was, but there was quite a bit written about it back in the late 80's (I think). Bottom line is that a speaker is a highly variable impedance load. I do impedance sweeps on speakers quite often and the variation (by frequency) is quite huge. So, it is not surprising that some amps "transfer" power differently at different impedances and therefore might sound different? - all being speaker dependent I'm sure
Anyway, this is a fascinating subject that has probably been covered somewhere here on AK, and I'm relatively sure it is and or will be fairly controversial :) For the moment I can only afford fairly low cost (and used) amplifiers. Many of which can sound very musical and are very enjoyable. Over the years, I have owned and played with cheap, mid priced, and horribly expensive amplifiers (both tube and SS). The big and heavy (and hot) Class A (or A/B switching that are biased heavily into Class A) amps sound really good - and they sound quite a bit different than "lesser" amps. I'm sure that the engineers can and will tell us why all amps sound different …. and they will also tell us why they all sound alike. At the end of they day, you have to make yourself happy and listen to what sounds really good to you :)
 
Personally, I think amplifiers all sound different. They may measure the same on paper but sound different.
There is also the speaker interaction with those amplifiers- synergy in the system as a whole or lack of it.

In fact, my latest discovery is that my two identical Sony TAN-77es power amps sound different to each other. They both are 100% perfect and test the same on my bench in all the important parameters.
 
Last edited:
Sorry - couldn't resist a cheap shot above!

There's a lot of different ways that amplifiers are built to do the same job, with different architectures, different components, and vastly different operating ranges that can be chosen by the designer for the same components that a different designer uses.

I'm in the process of building a kit amplifier from a well known designer. A year or so after the design was complete and the kits began selling, the designer offered an "enhancement" consisting of adding a bit of resistance between two points on a single circuit. Reports from the field say the difference is night and day.

So, the short answer is: To amplify a music signal, there's lots of variables involved. And for every variable, there's many choices. Some won't work at all, some do work, others work really well, and sometimes some bits work really well at the expense of others.
 
The gear you listed are not amplifiers:

Harman Kardon 580i - receiver
Yamaha RX 550 - receiver
Harman Kardon AVR 125 - receiver
Yamaha HTR-5940 - receiver

In addition to an amplifier section, receivers also have a preamp section and often have other signal modifying circuitry. Different preamps are widely considered to have audible sound differences.
 
All amps sound different. Overall,I've tended to find the more expensive (MRRP wise) and heavier you buy... the better the SQ.
Dual trannies/power supplies,non switching functions,big caps,hi-speed resistors,plus the overall quality of components used will make all the difference in SQ.
 
Daunia 70 said:
All amps sound different. Overall,I've tended to find the more expensive (MRRP wise) and heavier you buy... the better the SQ.
Click to expand...

Agreed, all amps sound different for numerous reasons, many of which have already been mentioned.

Amps are like recipes and designers are like chefs. Ask 10 different chefs to make a dish and they will do so with 10 different recipes. Give 10 different chefs the exact same recipe and the end result will be the same dish with 10 slightly different tastes.

As for more expensive and heavier--better ingredients make for a better dish.
 
Amps are different , wider stage ,deeper bass. Some clear as a bell some muddy some funny. Some choke some never run out of gas . Some sweat some don't . Some Brite some dark . So to those that say that all amps sound the same ,how so? I own several pieces because they sound different . That to me is a good thing .
 
ssv1761982 said:
This is all using same Genesis 210 speakers the I bought when I originally got the HK 580i.
Click to expand...

Please don't forget that your receivers interact with your speakers. If you change your speakers and run the same tests the conclusion could be the same or completely different. There are too many parameters in the game of complex systems.
 
THis is one of those areas where measurements aren't completely useful. As mentioned, most decent quality amps measure so close to the same as to be indistinguishable from each other, yet they do sound different. Some may be speaker pairing, some may be some largely un-measured factor to do with passing multiple frequencies at once, or who knows what. Suffice to say, go between half a dozen good amps on the same speakers and its a fair bet that a person with good ears will say that they aren't identical. It may (and should) be small differences but they are there.


Also there is something to be said about operating condition of the unit in question. If we're talking about a 20+ year old rig, it may not perform to it's measured specs anymore. I rebuilt a tube amp over the weekend, and I could tell in about 30 seconds of listening that it sounded very different with fresh power supply parts vs how it sounded when I got it, and that was using all of the same tubes.
 
Amps "should" all sound the same. That should be the ultimate goal. Pure amplification.

The reason they sound "different" (Albeit very small differences compared to lets say, speakers) is because each manufacturer has their "house sound" signature imparted upon them.

I would venture that all manufacturers could build amps that all "sound" the same.
 
I've got a KR-9600, KR-6600 and KR-4070 that I've hooked up to the same turntable and speaker set up and they all sound different, in some way. The most striking is the KR-6600 that has a tremendous amount of bass. As a side note, I run all the controls flat when comparing.
 
Mark B said:
In addition to an amplifier section, receivers also have a preamp section and often have other signal modifying circuitry. Different preamps are widely considered to have audible sound differences.
Click to expand...

Integrated amps or receivers all have pre-amp and power amp section.

Receivers tough, have a ... tuner section that integrated amp do not.

Should a NAD 3020 sound different than a Nad 7020 because it has a tuner section ?

I do not think so.
 
Mark B said:
The gear you listed are not amplifiers:

Harman Kardon 580i - receiver
Yamaha RX 550 - receiver
Harman Kardon AVR 125 - receiver
Yamaha HTR-5940 - receiver

In addition to an amplifier section, receivers also have a preamp section and often have other signal modifying circuitry. Different preamps are widely considered to have audible sound differences.
Click to expand...

This is important to keep in mind. The OPs title question does not align with this actual situation. We can either talk about why receivers sound different (which would include their built-in preamp sections, tuners and maybe phono stages as Mark B pointed out), or we can talk about why amplifiers sound different which, in the OP's case, we could never know unless he can isolate the amp sections of his receivers and compare then with the same external preamp and sources.

But I kinda think he wants to know why his receivers sound different.
 
All well design amps will sound the same in my experience. If it sounds different then the amp is purposely bending the signal somewhere, components going out of spec or the amp was never a well designed amp in the first place despite it's price point.
 
Integrated amps and receivers have a different sound. The same can be said for speakers as well. I think it boils down to what speakers you are matching with the integrated amp or receiver. You need to have the most efficient speakers you can afford to handle the power of your integrated amp or receiver. Some combinations will produce "warm," "bright," or "tinney" sound. There may be others but these are the ones I am aware of.

To resolve the issue, you must consider both the speakers and your integrated amp or receiver in order to get the sound you are looking for.
 
HTWillie said:
Sorry - couldn't resist a cheap shot above!

There's a lot of different ways that amplifiers are built to do the same job, with different architectures, different components, and vastly different operating ranges that can be chosen by the designer for the same components that a different designer uses...
Click to expand...

I don't know if anyone believes that ALL amplifiers sound the same. Obviously, an amp that is out of spec due to age, damage or poor design will not sound the same as a properly functioning amp. Also, you really can't talk about amplifier comparisons without including the speaker(s), when connected they become part of the amplifier.
Regarding different topologies, there was an interesting test done by Quad engineers in the seventies. They placed a valve amp, a direct-coupled ss and a cap-coupled ss amp in a blind test and asked people which they preferred. You can probably guess the result but here's the original article:
http://www.keith-snook.info/wireless-world-magazine/Wireless-World-1978/Valves%20versus%20Transistors%20DCD.pdf

(For those that don't want to read the article...no amp was able to be differentiated from the others)
 
Last edited:
You must log in or register to reply here.
Back
Top Bottom