Sound Quality Vs. Measurements

[Wavebourn]

Here is picture of TGK-3 generator powering radio. Yes, they were used in some Siberian villages were electricity was not available yet (deep forests called Taiga), hundreds of kilometers from towns. I believe today they would be regarded as very audiophiley, no AC ripples at all.

[anatech]

Hi jcx,
Thank you! I can always count on you to liberate a smile from me.

BTW, I got me some of those radios. Some even older than that.

Hi Anatoliy,

It does, Chris

Well, as I said. It only matters when you approach the limits. In this case, maybe at 1/10 of the frequency where you begin to run into slew rate limits. If the amp is not being pushed, it will not matter. There are many asymmetrical responses in nature, and certainly in power amp designs. I think that making an effort to create symmetry in a design may require a compromise in more sensitive areas. It's really up to how you choose to design a circuit. It might be easier to stick with op amps selected for symmetrical behaviour if this is very important to you.

Hi a.wayne,

Chris while i do agree there are posers in the high-end, i have very rarely seen mid-fi beat high end for sonics.

Bright eyed optimism can't survive when you have worked in audio service for 35+ years. Believe me when I say, there are more aborted audio efforts produced by small high end companies than you really want to know about. Consider that I see equipment laid bare. I see the construction, the schematic (design) and components used. Then, it gets heard and measured. Over the years you get to see the weaknesses and design snafus, plus the rhetoric used to explain things away. That and the pure make-believe. I have stronger words for that, but this is a family site.

I have an extremely strong dislike for designers who are more ego than substance, and there is no shortage of those people out there. I see expensive poor designs as outright theft. There is no sugar coating that one. You know, I do respect equipment that is what it is advertised as. Just as I respect really good designs as well. I think it comes down to honesty and getting what you pay for.

Do you know that equipment that forgoes any kind of protection network for the speakers really do create fires. Most speakers burn (big surprise). The callus disregard some people have for others just so they can save a few bucks on missing protective circuitry garner my intense dislike. There are technical ways to accomplish speaker protection without using relays or fuses if they must. A Carver amplifier represents an excellent example of this.

I agree somewhat , but committees do fail too , many design by committees were utter failures

Oh, absolutely! However, engineers each have things they do better than others. They have a knack for some circuit types and understanding how each part work. You have a design leader, and individuals that contribute circuits they know best that are integrated properly. There is far too much money at stake to mess up when you create thousands upon thousands of each model. There is no "let's fix it in the field" thinking that is acceptable. So while these products may not represent the pinnacle of audio art, they do represent good value, good performance and a reasonable expectation that they will not burn your speakers (and house) to the ground. We also did insurance inspections and repair. We did see equipment that did nasty things by design. They didn't fail safe, which is an important concept in industrial, military and consumer product development. Amateurs who think they design audio equipment do not generally design in "fail safe" concepts. They are not even aware of it for the most part.

-Chris

[anatech]

Hi Anatoliy,
Now, that's cool!

I like that setup. I mean - for real.

[Wavebourn]

Chris;
symmetric slew rate does not mean symmetric topology. And symmetric topology does not guarantee symmetric slew rate. I put in this thread already some pictures with explanation, may be half of hundred pages ago.

Also, Doppler effect, non-linearities: of air, walls, whatever, we don't hear as distortions. We hear them as cues to surrounding. But as soon as it differs a tiny bit our ears pop up: "Was ist das?!"

[wahab]

Originally Posted by Wavebourn

no AC ripples at all.

Provided the heat source has constant dissipation....

The variation will be integrated by the thermal inertia , though...

[gaetan8888]

Originally Posted by anatech

Hi a.wayne,

There are technical ways to accomplish speaker protection without using relays or fuses if they must. A Carver amplifier represents an excellent example of this.


-Chris

Hello Chris

Other than the standard current limiting circuit ?

Can you say more about that, any practical exemples ?

Thank

Bye

Gaetan

[Wavebourn]

Do you know Chris that a camel is a horse designed by committee?

[abraxalito]

Very unfair on camels Wavebourn and a huge over-estimation of the effectiveness of commttees - a camel is truly a masterpiece of adaptive fitness.

[godfrey]

Originally Posted by tvrgeek

Or how C6 is calculated. I came up with 72K but that is a total guess that it is the 220p and 10K of R5.

C6 interacts with R3, R4, and the dynamic emitter impedances of Q1 and Q2. A crude calculation suggests the resulting phase lead is maximum around 10MHz.
edit: The effect of R5 is negligible.

[dvv]

Originally Posted by a.wayne

Name a high feedback back amplifier considered to be good sounding , contrary name a low or zero feedback amp considered bad sounding . The Audio Note UK amp discussed previously , failed every test known to man , yet it got a pass for sound ...


PS: Please quantify high feedback and low feedback ..........

For the first question, I'll name Laverdine. Their feeling is that feedback is good, and assuming your amp satisfies a list of criteria in open loop, it doesn't matter how much feedback you use. One of the criteria is that the amp's open loop full power bandwidth must be 30 kHz or more.

For the second, please re-read my original post, I was quite specific: up to 20 dB is low, up to 28 dB is medium, and above is much. This is, quite obviously, a very personal classification, no universal truth.