All well made good amps should sound the same..

[cafe latte]

But they Err dont... Why is it so hard to make an amp just do what it is supposed to which is just amplify equally across the frequencies? I have three amps I built myself and a Ming Da valve amp with 300b valves. The three I built were all made carefully and all the designes apparently gave very accurate freq curves from 10-20 hz to 50Khz yet listen to the amp one after another and the differences in treble and bass are staggering. I think the same goes for speakers and turntables in that getting it right seems to be very hard when really it souldnt be IMP especially for amps.
Any thoughts
Regards
CL

[Ldg]

My 2p worth :

Neither amp specs nor speaker specs are comprehensive, and typically miss some of the biggies which describe how they interact. Speakers are actually current driven devices, with complex impedances. Wheras, conventionally, power amps are voltage amplifiers and specs typically treat them as such.

But aspects of transconductance apply. And parameters such as current slew rate, peak current, transconductance curves are in play. But because they're never discussed or specified, people seldom consider them as factors. Whereas they can be defining, and often might explain the answer to your question, perhaps CL.

[jake]

The most fascinating thing in audio is how different well-made amplifiers sound, even with exactly the same specs. My amp has below average specs but sounds better than a Chord to me. Specs are for suckers. Get the best transformers possible, try to make the rest of the system as transparent as possible.

[raphaelmabo]

Specifications does not tell about the coloration of the sound and the coloration gives the sonical character. In the perfect world, an amp should just add gain to the signal without adding or withdraw anything, but in real life it isn't that simple. The sound signal is coming through electronics and the elctronic components adds and withdraw things from the sound.

[Ldg]

Specs are for suckers

Well, failing to look at those aspects which determine performance might be for suckers.......but one can't really blame the innocent for being misled in such things, there's a whole machine which was geared to churn out the propaganda which leads one to evaluate amps on an incomplete set of parameters, for example. And it's not just amps which that could be said to apply to in audiophillia.

If one is designing the things, or setting out to determine what's really going on, it seems fathomable enough if one digs hard.

In the perfect world, an amp should just add gain to the signal without adding or withdraw anything

I don't disagree, but it illustrates what I mean here. Because 'gain' conventionally is taken to mean 'voltage gain' and the power amp 'problem' is thought of in perfect voltage amplifier terms. Rather than in transconductance terms. The very very early audio amplifiers addressed this issue, and it all got lost somewhere in the 1940s AFAIK.

Speakers are ultimately motors, current operated solenoid coils where motive force is proportional to current. A big clue is that the unit of magnetomotiveforce is the amp or amp-turn ! But conventionally, speakers are voltage driven as though they are resistors - indeed even designed to try to behave like that. But it ain't natural.....and the whole scene has non-ideals that aren't even discussed. There are a few power amp designers, not least Mr Pass who have published perspectives on this. It's as much an issue with post 1940s speakers as power amps - the path the industry took.

[cafe latte]

Specifications does not tell about the coloration of the sound and the coloration gives the sonical character. In the perfect world, an amp should just add gain to the signal without adding or withdraw anything, but in real life it isn't that simple. The sound signal is coming through electronics and the elctronic components adds and withdraw things from the sound.

Electronic components dont do anything to the sound, the circuit as a whole might. I have never heard any difference replacing caps with super special audiophile ones for example. The most neutral amp I have is my elliot sounds mosfet which I built about a year ago.
I wonder how much damping factor has to do with the audiable differences when considering amp design? I am aware of the effect with bass , but will it effect the the highs too I wonder? My 46wpc class A monoblocks IMO is not as sharp on the highs as the elliot sounds with normal speakers but with the esls it is which is odd as despite the design being for esls it is supossed to be also fine with regular speakers. I must pull the paperwork out again and have a look as I built it years ago.
Regards
CL

[Tedrick]

I, for one, am glad that components sound different. This hobby would be boring as hell, in fact it probably wouldn't even exist, if everything sounded the same.

[jake]

True that, take each one as they come, no prejudge.

[cafe latte]

I, for one, am glad that components sound different. This hobby would be boring as hell, in fact it probably wouldn't even exist, if everything sounded the same.

Yes and no, the point I was getting at is two very well made amp sound very different to each other then one is in effect not doing its job very well. If two amps are supossed to be accurate across the frequency range to within a few dbs ie reproduce all freq accuratly then the two amps should sound very similar. The big surprise in my case and probably it is the same for many amps the difference was staggering in both the treble and the bass which it shouldnt be.
Regards
CL

[Tedrick]

Yes and no, the point I was getting at is two very well made amp sound very different to each other then one is in effect not doing its job very well. If two amps are supossed to be accurate across the frequency range to within a few dbs ie reproduce all freq accuratly then the two amps should sound very similar. The big surprise in my case and probably it is the same for many amps the difference was staggering in both the treble and the bass which it shouldnt be.
Regards
CL

If all amps were designed exactly the same, then yes they should sound the same into the same pair of speakers. But since amplifiers use a dizzying array of different circuit topologies, there are just too many variables in play to reasonably expect all "well made good amps" to sound the same. Most likely it is a matter of the two amps doing their jobs differently.

It's no different that cars, bicycles, wine, computers, speakers, etc. etc. Each is designed or created to achieve a different design objective, so they necessarily won't perform the same.

[cafe latte]

I agree there will be differences , but what is not expected is such differences at frequency extremes. If an amp is supposed to be accurate to + or minus nothing then it should at least sound similar to a similar speced amp in regards to frequency response IMO.
Regards
CL

[Trackside]

Frequency response is only one parameter responsible for the sound.The speed at which an amp or any audio component responds to a signal at a particular frequency will change how it sounds even if the frequency response in DB is identical. If it's better at responding to HF it may well 'sound' more detailed and with seemingly more HF 'lift' even if on a frequency analysis it's identical. I'm all for measurements and specifications but what's easy to measure may not be important and what's important may not be easy to measure.

[Tedrick]

I agree there will be differences , but what is not expected is such differences at frequency extremes. If an amp is supposed to be accurate to + or minus nothing then it should at least sound similar to a similar speced amp in regards to frequency response IMO.
Regards
CL

Amps are measured into a static load, aren't they? But speakers are very dynamic devices, often with very complex impedance curves. Different amps will behave, and sound, differently when driving that dynamic load.

[cafe latte]

I agree there will be differences , but what is not expected is such differences at frequency extremes. If an amp is supposed to be accurate to + or minus nothing then it should at least sound similar to a similar speced amp in regards to frequency response IMO.
Regards
CL

Amps are measured into a static load, aren't they? But speakers are very dynamic devices, often with very complex impedance curves. Different amps will behave, and sound, differently when driving that dynamic load.

But a well made amp should cope with this and still desplay a flat freq response unless the speaker is a particularly difficult load IMO.
Regards
CL