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Testing audiophile claims and myths - Page 150

post #2236 of 2566
Quote:
Originally Posted by jaddie View Post


Yes, but those grounds get co-mingled in real life as well. It only takes one device to "break the rules".

Care to elaborate on your comment?


And therein lies the problem!  Things like electricians treating all Safety Grounds as equals. 

We need to look at Mother Earth, Safety Grounds  and audio system ground as 3 different areas.

 

I'll PM you some docs at your web-page.  But it may take some time. (as it's a Holiday weekend and it's not raining right now).

post #2237 of 2566
Quote:
Originally Posted by Speedskater View Post


And therein lies the problem!  Things like electricians treating all Safety Grounds as equals. 

We need to look at Mother Earth, Safety Grounds  and audio system ground as 3 different areas.

I agree, we need to look at them as different areas.  However, they aren't in real life.  A simple example would be an RCA connector mounted to a metal chassis to which the third pin of the power cord is also connected.  No matter how other gear in the system is done, once connected to that device, we have a problem.  Or an AVR with separate chassis and HDMI grounds connected to a display with common HDMI and chassis grounds.  Happens every day thousands of times.

 

The blog post was not intended to explore grounding from a standpoint of what's proper for signal, safety and earth, it's about surge protection.  A many kilovolt surge won't differentiate between the three much, in fact, keeping them partially isolate could increase the chance for damage.  The take away should have been that common-mode surge protection requires a good earth ground, which can only be accomplished at the breaker box.

 

It's a knotty problem without a good practical solution because manufacturers of AV equipment, electricians and installers all have their own idea of how grounds should be connected.  Often, one shorts the others well-intentioined attempt.  

Quote:
Originally Posted by Speedskater View Post

I'll PM you some docs at your web-page.  But it may take some time. (as it's a Holiday weekend and it's not raining right now).

Thanks, I appreciate that and look forward to reading them.

post #2238 of 2566

Looks like another website sold out to advertiser pressure. Check out the link that used to talk about the Stereo Review Amplifier Challenge

 

3 - Do all amplifiers sound the same? Original Stereo Review blind test.

 

(The original Bruce Coppola link is broken, this link is the best descriptive of the test with soem of the original images, I can find)

http://www.hometheaterfocus.com/receivers/amplifier-sound-quality.aspx

A number of amplifiers across various price points and types are tested. The listeners are self declared believers and sceptics as to whether audiophile claims are true or not.

There were 13 sessions with different numbers of listeners each time. The difference between sceptic and believer performance was small, with 2 sceptics getting the highest correct score and 1 believer getting the lowest. The overall average was 50.5% getting it right, so that is the same as you would expect from a random guess result. The cheapest Pioneer amp was perfectly capable of outperforming the more expensive amps and it was ‘striking similar to the Levinson‘.

post #2239 of 2566
Quote:
Originally Posted by bigshot View Post

The cheapest Pioneer amp was perfectly capable of outperforming the more expensive amps and it was 'striking similar to the Levinson.'
LOL, I'm glad to know that my $150 Pioneer receiver has been vindicated. cool.gif

--Ethan
post #2240 of 2566

Good to know.  I'm planning on purchasing a Pioneer VSX amp soon.  Mostly I want it because it can decode FLAC through USB up to 24/192.

post #2241 of 2566
Quote:
Originally Posted by EthanWiner View Post

LOL, I'm glad to know that my $150 Pioneer receiver has been vindicated. cool.gif

--Ethan

Hey Ethan, didn't know you were here two. I'm immensely enjoying your book at the moment and looking forward to some room measuring and DIY acoustic treatment project.B-) I would be intested to hear your opinion on the influence of headphone amps on headphone listening. I mean since no room is getting in the way... Greetings from Germany
Edited by SonicSavour - 10/10/13 at 3:22pm
post #2242 of 2566

Output impedance is the main technical aspect why headphone outputs sound different. It not only influences the output level (depending on the load impedance, also see level matching below) but depending on the impedance curve of the headphone also the frequency response.

Some devices also have too small output caps which causes bass roll-off.

 

Psychological factors include all kinds of biases. Not properly matching the levels means that the amp with higher gain will usually win. There's also price tag, brand name and reputation, looks etc.

post #2243 of 2566
Quote:
Originally Posted by SonicSavour View Post

I would be intested to hear your opinion on the influence of headphone amps on headphone listening.

xnor already gave you good explanations. Most solid state amps these days are transparent enough to not matter.

--Ethan
post #2244 of 2566
Quote:
Originally Posted by EthanWiner View Post

xnor already gave you good explanations. Most solid state amps these days are transparent enough to not matter.

--Ethan

Exept for those multi BA inears where even a 10 Ohm output could lead to a weird frequency response.
post #2245 of 2566

Yeah unfortunately the 0 ohm output commonly seen in speaker amps is still not standard in headphone amps. That manufacturers like beyerdynamic and Sennheiser release amps with 100 and ~40 ohm output impedance doesn't help either. -_-

post #2246 of 2566
Quote:
Originally Posted by bigshot View Post
 

<snip>

 

3 - Do all amplifiers sound the same? Original Stereo Review blind test.

 

<snip>
 

 

Do all amplifiers sound the same can be found here: http://webpages.charter.net/fryguy/Amp_Sound.pdf


Edited by upstateguy - 10/13/13 at 9:15pm
post #2247 of 2566

i agree with you,I do not think that many with expensive gear are going to be enamored with those results.thanks

11.gif

post #2248 of 2566

I just got done reading that 12 page whopper on USB cables in the PC Audio forum and I really must say.

 

I listen to Coast to Coast AM at work for what I will describe as "for fun". I don't believe in UFOs, or shadow people, or homeopathy. I think it is all nonsense, and science says it is. They continually talk about how the "scientific community" refuses to believe their anecdotal evidence. There are boatloads of people that believe some absolutely insane things. 

 

This is the same kind of thing I see when the debates over cables come up. Especially what I just finished reading. That thread turned into a real whopper. Some of the arguments for the USB cables, in my opinion, sounded a lot like a typical Coast to Coast episode about UFO sightings or Bigfoot. \

 

"I know what I saw!!!"

 

I would like to audition some cables and stuff for myself, and may do so when the opportunity arises (and if I can get a refund). Though, since I won't be going in with an open mind, I doubt I'd hear anything.

 

Just my observations... 

post #2249 of 2566

An open mind is essential, yes, but so is a proper test.

 

Because if you've read all the wonderful reviews of cable X and you accept the claims blindly then you will probably hear a difference.

post #2250 of 2566

That is how I feel about it as well. Your signature sums it up nicely. 

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