|
General Asylum General audio topics that don't fit into specific categories. |
|
|
|
General Asylum General audio topics that don't fit into specific categories. |
|
In Reply to: For marginal designs, perhaps, posted by Al Sekela on December 28, 2005 at 08:42:29:
I think that if you did some testing, you'll find that most every amplifier made responds to dynamic signals fed into complex impedances in a different manner. Not only do they respond differently from one another, each individual unit can lack consistency at various frequencies and / or as amplitude is varied within its' own rated parameters. This has to do with load stability, circuit design, transient response, power supply design, etc...Should one doubt this, John Atkinson makes note of this on the recently tested PS Audio Gain Cell in Stereophile. At 38 watts and above, the distortion byproducts of the amp itself tend to escalate as frequency climbs and greater power delivery is required. This demonstrates the non-linear nature of this product and how the sound can change with both amplitude and frequency. On top of that, this unit showed inconsistent results at various impedances, much like the "Class A" rated PS Audio HCA-2 before it.
This further complicates "what the amp sounds like" as EVERY speaker known to man varies the complex impedance that the amp sees as frequency and amplitude changes. Factor in that different loudspeaker cables introduce further impedance variations into the equation and you have a complete lack of consistency from installation to installation with a product like this. That is, one would have no idea as to what an "unstable" amplifier will "sound like" at any given time as the terminating impedances are varied and the amplitude and frequency of the signal shift dynamically.
In effect, a "review" of a product like this would be STRICTLY subjective based on the componentry and system that it was connected to at the time of listening. If it weren't for our ability to both quantify ( measure ) and interpret the provided technical data ( THANK YOU Stereophile & JA ) with some form of consistency, we would be wasting our time.
Obviously, there are some "inconsistent" things going on in both amplifier design / circuit stability AND how specific products are rated. If one does their homework, i think that they would find that many of the variances that we hear and experience are based on problems within the audible pass-band. These in-band problems may be the result of external out of band aggravations, but the results are still displayed within the audible pass-band, hence our ability to hear and discern them. Proper design can negate much of this, but most designers end up drastically complicating the circuitry trying to compensate for what was originally a poor design. In most cases, this only adds more room for additional errors and signal degradation rather than fixing the problem.
If manufacturers were to design the circuit as simply and as robust as possible, many of the "stability" problems that we encounter would never come into play. That's because the circuitry would be fast enough to properly respond in a timely manner AND "sturdy enough" to supply the power on an as needed basis without slewing induced distortions creeping into the scenario. Circuit speed, which is a by-product of wide-bandwidth, and volt / amp ( power ) potential are the key factors that really need be addressed in most circuits. If you can get both of these right, the rest seem to fall pretty much in place IF carefully executed. Lacking ANY part of the required speed and power potential required to get the job done opens up a multitude of potential problems.
Here's the big problem. Most "modern designs" utilize the exact opposite approach i.e. slower circuitry that is bandwidth limited fed by an under-sized power supply. This introduces slew rate limiting and in-band phase shifts. This is why many "digital" based products lack the proper pace, rhythm and timing i.e. errors in both the amplitude domain and time domain. Since "music" is all about dynamics ( amplitude ) and rhythm ( timing ), it ends up taking a beating.
The effect that we hear in music reproduction is that the music sounds flat, un-dynamic and lacks in the "toe-tapping" department. In effect, what we are hearing is a "reproduction" of the music that has been digitally broken down bit by bit and re-assembled bit by bit with TONS of minute artifacts both lost and introduced. While truly state of the art digital has gotten much better in this regards, these very factors are why many people prefer the analog medium over the digital medium.
The scary thing to me is how many people try to compensate for one error ( poor digital ) with another error ( poor linearity ). That is, they introduce further errors into the system via non-linear distortions and tonal imbalances ( tubed circuitry ) in order to try and "balance things out". In effect, they might end up with something that is more pleasing on the whole, but it is a very round-about approach to say the least. The more appropriate and beneficial approach would be to seek out higher quality gear that is more linear and "universal" in application. This type of gear will do less damage to the music due to preserving what was originally recorded. On top of that, this type of gear will provide more consistent results from system to system too, making the need for "subjective reviews" a thing of the past.
The major problem that WE all keep coming back to is the low quality of typical recordings. As we all know, this variable is typically FAR beyond our control or input. As such, some give up on trying to achieve a "high fidelity" ( accurate ) system and end up seeking out a "musical" ( albeit "inaccurate" ) system. Since we are the only ones that have to listen to our systems, this is why we see such a diversity in systems and products available.
The end result is that there really is no "right" way to build a system anymore. What we as "audiophiles" originally sought to achieve many years ago i.e. "high fidelity playback of the original recorded event" is no longer a primary goal for most "audiophiles". Like most things, the ideas of "perfection" have been corrupted by reality. In cases like this, the end result will always boil down to personal preference since there is no real way to achieve and / or measure "perfection" itself. Once the source is tainted, one can only "interpret" what they themselves deem to be both "important" and "the truth". Sean
>
This post is made possible by the generous support of people like you and our sponsors:
Follow Ups
- Oversimplification: "Class A rated" vs "marginal designs" - Sean 12/28/0510:49:23 12/28/05 (1)
- Re: Oversimplification: "Class A rated" vs "marginal designs" - Inmate51 08:32:38 12/29/05 (0)
Top of Page ]
[ Contact Us ]
[ Support/Wish List ]
[ Copyright © 2025, Audio Asylum, all rights reserved ]
