I read the Audio Critic Article that JohnK linked to and note that the writer expresses exactly the tone and content of the great and accepted wisdom that all amplifiers sound the same subject to the proviso - all things being equal.

Now, I assume that we're not really reducing comparisons to only identical units as that condition would tend to reduce all tests to a tautological and meaningless exercise - except for quality control of course.

Here is the intro piece to which JohnK linked:

Quote:

Every low-distortion electronic signal path sounds like every other. The equipment reviewers who hear differences in soundstaging, front-to-back depth, image height, separation of instruments, etc., etc., between this and that preamplifier, CD player, or power amplifier are totally delusional. Such differences belong strictly to the domain of loudspeakers. Depending on the wave-launch characteristics, polar pattern, or power response of the loudspeaker (those are overlapping concepts), the stereo presentation of the program material can vary greatly. It cannot vary as a result of the properties of a normal (i.e., low-distortion) electronic signal path. The only exception I can think of would be totally inadequate channel separation (less than, say, 30 dB) between the left and right channels of a stereo device, which is hardly ever the case—and certainly not when high-end components are being discussed by said reviewers.



Beware, therefore, of electronic audio components with a personality. If they have a personality, they are either defective or the brainchild of a reviewer without accountability.





Now, clearly this is the mantra, the clear and barbed statement of the orthodox position here. We have heard variations on this theme suggesting that anyone whose experience suggests a different result only thinks they hear a difference and that perceived difference is the consequence of psychological factors rather than any quality inherent in the equipment.

Clearly an amplifier produces an output which can be measured according to various parameters. I am not an engineer and have no background in engineering. I understand that what I'll call the 'engineer's' position assumes these measurable variables are sufficient to describe the entire range of performance of an amplifier when it comes to amplifying a complex wave form which is music. May I assume that when engineers test an amplifier and measure its characteristics they are not doing so with a complex wave form? If so, the assumption must be that the test signal is sufficiently analogous to music such that measurements of a reduced set of parameters will be sufficient to describe the performance of an amp when the amp is called upon to do more than amplify a test signal.

It seems to me, and again, I'm not an engineer and therefore I am more modest in my contentions, that engineers make certain assumptions which may or may not be true.

Then there are people who claim to hear a difference. Engineers cannot measure or even identify the processes at work when it comes to the operation of the greatest sound processor in the universe ... that messy, gelatinous, crenelated, wet 1350 gram lump of mystery that resides in most crania.

Proponents of the orthodox view seem to hold, and correct me if I'm wrong, that engineers measure every significant, meaningful characteristic of an amplifier. I don't know if this is true or not. Of course, an engineer can say, "you don't know if it is true or not because you don't know enough," and they would be correct.

However, the assumption that they know everything that is knowable about an amp's ability to reproduce a complex musical wave form is similarly suspect.

Clearly, if someone believes the orthodox reductionist and positivist contention, then selection of an appropriate amplifier is easy. Select one which is reported to produce the desired output in watts per channel at an acceptable distortion level ... one which is equal to or less than the distortion characteristic of the speaker, has adequate controls, aesthetic appeal and low price.

Now, my experience suggests that the orthodox position is inadequate to account for the observable variations in the ability of amps to reproduce music. The problem is that the measuring device, the human brain/auditory system does not have measurable specs which measure soundstage, tone, timbre, bloom, blatt, or any of the qualities which some folk value in their sound equipment.

Some may say that since these qualities are not measurable, they don't exist. Philosophically, this is a suspect proposition.

I use separates. I'm pretty happy with my systems. I have had many receivers over the years. I liked some, and did not like others. For instance, my Onkyo 797 was good. My Technics SX 940 which I picked up for a bit over a hundred dollars sounded better. (compared as to 2 channel music reproduction) in my room, to my ears, using the same source component, etc., etc. Why? I wouldn't even presume to know the answer to that, except to say that when I open a receiver and look at its amplifier section, or open an amplifier I see many components, each of which plays some part in the process. It seems to me that architecture, design, component quality, interaction between those components play some part in the output.

I don't believe an amp is a black box with receives a signal from a wire and which delivers an amplified signal out into another wire which signal is identical to the input in all regards except for wattage.

Your opinion may differ.

Enjoy the Music. Trust your ears. Laugh at Folks Who Claim to Know it All.