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Testing audiophile claims and myths - Page 203

post #3031 of 3264
Quote:
Originally Posted by esldude View Post
 


Actually the waveform you are referring to is caused by reduced low frequency content.  There is no initial LF response that is larger.  Square waves are sines with odd harmonics.  The initial edge is from higher harmonics.  So were this a low frequency part of music the amp won't respond with an initial higher level that fails to continue on.  It will simply respond at a lower level, and that is it.

That is another interpretation. 

 

Fact remains that it takes larger voltage swing in an amplifier and greater headphone or speaker excursion to reproduce limited LF response square wave than required for a (near) DC amp - for the same reference level in the midrange, usually 1 kHz. That makes LF limited response amps audibly "louder" in the bass.

 

This fact also means that LF limited amp can reach clipping point earlier than (near) DC amp - for the same power rating and same midrange reference level. This IS important, as bass is usually the part in the audible spectrum that takes the lion's share of power. A clipped amp will definitely sound different than one still working within its limits. The differences can be more than 3 dB in the actual SPL achievable, therefore clearly audible. 3 dB SPL is the difference between a 100 and 200 W/ch amp, for example.

 

No matter how interpreted, it is a deviation from the original signal, it is a form of distortion and it is audible. The problem is compounded by the fact that in any real scenario there are many (pre)amps connected in series - there can be quite a few from the microphone to the actual amp driving one's headphones or  speakers. All those LF rollofs simply add and by the time final output is reached, the original waveform can be objectionably audibly distorted.

 

It is one source of  why the amplifiers can sound differently, despite being used well within their power limitations and their specs being well in excess of what is required in terms of noise and non linear distortion(s).


Edited by analogsurviver - 8/17/14 at 11:43pm
post #3032 of 3264
Quote:
Originally Posted by analogsurviver View Post
 

That is another interpretation.

It is the correct interpretation, mathematically. The peak levels in the amp with a bass rolloff are no higher than they are in an amp with extended low frequency response. As a result, it will not clip any sooner.

 

 

post #3033 of 3264
Quote:
Originally Posted by cjl View Post
 

It is the correct interpretation, mathematically. The peak levels in the amp with a bass rolloff are no higher than they are in an amp with extended low frequency response. As a result, it will not clip any sooner.

 

 


Yes except for phase delay which is what was being shown in the video.

 

http://www.kennethkuhn.com/students/ee351/square_wave_testing.pdf  This shows such results.

 

If you merely reduced low frequency content you get a drooped response between the ends of the square wave.  If there is phase delay you get the sloping tops and bottoms.  A coupling cap would cause reduced LF response and do so by delaying the lower frequencies.  Which gives the sloping result.  The initial edge will rise and the trailing edge troop.

 

But that doesn't mean LF is more prone to clipping.  The higher leading edge is due to higher frequencies present, not lower ones.  The lower ones that somewhat cancel some higher harmonics are delayed and you see that in the trailing edge where the same higher harmonics are more suppressed. 

post #3034 of 3264
Quote:
Originally Posted by esldude View Post
 


Yes except for phase delay which is what was being shown in the video.

 

http://www.kennethkuhn.com/students/ee351/square_wave_testing.pdf  This shows such results.

 

If you merely reduced low frequency content you get a drooped response between the ends of the square wave.  If there is phase delay you get the sloping tops and bottoms.  A coupling cap would cause reduced LF response and do so by delaying the lower frequencies.  Which gives the sloping result.  The initial edge will rise and the trailing edge troop.

 

But that doesn't mean LF is more prone to clipping.  The higher leading edge is due to higher frequencies present, not lower ones.  The lower ones that somewhat cancel some higher harmonics are delayed and you see that in the trailing edge where the same higher harmonics are more suppressed. 

Ahh - you're right. I'd forgotten the impact of the phase shift. Sorry about that one (clearly, I need to go in search of more caffeine this morning).


Edited by cjl - 8/18/14 at 1:10pm
post #3035 of 3264

Here's some Schiity advice:

 

Regarding power chords for use with Schiit's highest end amplifier:

Quote:
11 Power Cord. Plug the end of the supplied IEC cord in here. You can also use fancy audiophile types, but they won’t really do anything—what about the thousands of feet of crap copper cables in your walls, huh?

 

Regarding fuses for use with their highest end amplifier:

Quote:
Hey, can I replace the fuse? Sure, you can, but it won’t make it sound any better. Don’t use anything other than a 3A slo-blow 5 x 20mm fuse.

 

Excerpts from the manual of the new Ragnarok

 

Cheers

post #3036 of 3264
http://www.theguardian.com/technology/2014/aug/21/mp3-cd-24-bit-audio-music-hi-res

A very misleading article. Listening set up by an audio store. No blind testing/ probably different masters used.
Edited by James-uk - 8/21/14 at 10:10am
post #3037 of 3264

interesting article...but definitely flawed

post #3038 of 3264
Thread Starter 

Various links repaired and a tidy of the OP. Glad to see this is still continuing. Thanks.

post #3039 of 3264
Ie
Edited by LivingVoice - 9/13/14 at 12:20pm
post #3040 of 3264
Science is hard.
Edited by Hapster - 9/14/14 at 6:02pm
post #3041 of 3264

living the dream. I would expect that cable to make the girl I like to love me(but then it better not be in an incremental way, else I'll have to buy a lot of cables).

post #3042 of 3264
Quote:
Originally Posted by castleofargh View Post

living the dream. I would expect that cable to make the girl I like to love me(but then it better not be in an incremental way, else I'll have to buy a lot of cables).
I thought girls were more interested in tubes.
post #3043 of 3264
Quote:
Originally Posted by headdict View Post


I thought girls were more interested in tubes.

cables, tubes... same difference. anything long that you can plug in ;)

post #3044 of 3264
Quote:
Originally Posted by headdict View Post


I thought girls were more interested in tubes.

:normal_smile :

 

 

Anyways. I have a question.

AFAIK the entire point of tubes is to color the sound, to make it less hi-fi for the sake of more pleasing sound. Then what is the point of trying to make a neutral tube? If one wants neutrality, surely a solid state amp would get you there easier...

post #3045 of 3264
Quote:
Originally Posted by Dark_wizzie View Post

normal_smile%20.gif


Anyways. I have a question.
AFAIK the entire point of tubes is to color the sound, to make it less hi-fi for the sake of more pleasing sound. Then what is the point of trying to make a neutral tube? If one wants neutrality, surely a solid state amp would get you there easier...
Fully agree. There is no point. Even girls would not be impressed by neutral tubes. Solid state, on the other hand, ...
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