Blind Listening Tests & Amplifiers - Page 99 - diyAudio
Go Back   Home > Forums > Amplifiers > Solid State

Solid State Talk all about solid state amplification.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Closed Thread
 
Thread Tools Search this Thread
Old 15th April 2003, 10:01 PM   #981
diyAudio Senior Member
 
fdegrove's Avatar
 
Join Date: Aug 2002
Location: Belgium
Default DOUBLE BLIND DOUBLE DEAF.

Hi,

Quote:
...so....if you 'agree with jc's approach', we can safely conclude that you 'agree' with his findings, and that therefore the majority of this thread has been a profound and an heroic waste of time?
It's not because I agree with this way to go about DBT that I agree with the heap of crap I read in this thread.

Any kind of measurement and testing is very useful, at the end of the day however it all depends on the intelligence of the person(s) interpreting the result(s) and how to draw conclusions from them.

Hope you can spot the difference?

Cheers,
__________________
Frank
 
Old 15th April 2003, 10:04 PM   #982
diyAudio Member
 
Peter Daniel's Avatar
 
Join Date: Jul 2002
Location: Toronto, Canada
Send a message via AIM to Peter Daniel
Default Re: Re: Bandwidth.

Quote:
Originally posted by mikek



the majority of this thread has been a profound and an heroic waste of time?

For some it was waste of time, and for some good entertainment, especially some of your posts
__________________
www.audiosector.com
“Do something really well. See how much time it takes. It might be a product, a work of art, who knows? Then give it away cheaply, just because you feel that it should not cost so much, even if it took a lot of time and expensive materials to make it.” - JC
 
Old 16th April 2003, 01:15 AM   #983
diyAudio Member
 
mrfeedback's Avatar
 
Join Date: Feb 2002
Location: Perth, Australia.
Default Worlds Cleanest Amplifier.

The only amplifier in the world to challenge a theoretical limit unprecedented harmonic distortion levels of less than 1000 parts per billion
Over the past 50 years it has taken the typical audio manufacturer 50 years to reduce distortion at 20kHz from .1% to .01%. Now, with a single revolutionary technological advancement, Halcro™ has reduced distortion to less than 0.0001%. In fact, all unpleasant distortion in the output stage has been virtually eliminated.

Quote:
Technical Paper
Written by Bruce Candy, Physicist, Halcro Research & Development Director

I have loved music all my life, been keenly interested in electronics since about 11 years old, and have very unusual ears; I can hear up to 23kHz in one ear and 21kHz in the other.

For many years I have been the Research & Development director and principal designer of several highly successful electronic companies, which have received many awards, but none of these embraced my passion for music and Hi-Fi.
About 10 years ago, I decided to try to eliminate the harsh sound from transistor amplifiers, for my own pleasure. I think I have succeeded. The result is now manifest in the Halcro amplifiers that exhibit harmonic and IM distortion levels many hundreds of times lower than the typical lowest distortion amplifiers. The best dm68 so far produced measured <25 parts per billion harmonic distortion at 1kHz (!), and the worst unit is a mere 600 parts per billion at 20KHz at full power, a frequency where most amplifiers exhibit very poor behaviour.



It could be said that the skill of an acute audiophile ear resides in its ability to perceive false signals among desired signals. One obvious aim of the Halcro technology is to reduce false signals to such a low level that they are quite inaudible. The international specified intermodulation tests (IHF-IM and SMPTE-IM) are indicative of the extent to which false tones are generated by an amplifier.

These tests apply, simultaneously, different inharmonic tones to the amplifier, as is the case with music (chords for example). The level of false inharmonic tones is then measured. The threshold of hearing of the human ear is attained when a pure tone (1kHz) of about 10microV is applied to a typical high-end loudspeaker (90dB @ 1W @ 1m) at a typical listening distance. All Halcro products produce false tones at considerably lower levels than this threshold at typical loud listening levels. No other amplifier company can make this claim.


It is often assumed that if the distortion of a product is less than the measured noise, then it is necessarily inaudible. This is not necessarily so. As is well known, ears behave much more like spectrum analysers for short periods rather than time-domain analysers. It is thus also well known that ears can detect tones or specific frequency spectra in noise even if the noise is far greater in amplitude. Hearing a conversation in a noisy crowd is an example of this, where one's brain continually selects frequency spectra to optimise the signal to noise ratio. In order to measure the THD + N across the audio band, the measuring FFT analyser's bandwidth needs to be set to 100kHz to measure at least up to the 5th harmonic of 20 kHz.

If an amplifier has an input referred noise of, say, 10nV/sqrt(Hz) and a gain of 30, then the measured noise is 10nV/sqrt(Hz) x sqrt(100,000) x 30 = 100microV; that is substantially more than audible 10 microV referred to above.
Even though this noise voltage is far greater than the 10microV-tone limit of a human ear. It is interesting to note that the same ear would be quite incapable of detecting this noise. Simply because the noise density is low: the human ear can easily hear a difference of 1Hz at 1 kHz, and the noise density in a 1Hz band is, of course, 10nV/sqrt (Hz) x 30 = 0.3microV only.

It therefore seems strange to me that distortion is measured to include noise, as one can definitely hear signals of amplitude substantially less than the noise measured in the distortion + noise measurements.
The reason, I assume, is historic: Early THD analysers simply measured THD + N, whereas it is now possible to measure arbitrary low noise floors depending on the ability to notch out the fundamental and the frequency point spacing in the FFT analysis.

However, to what extent a good ear can hear below the measured amplifier noise when music is produced is difficult to assess. These sorts of arguments pervade discussions in the industry. For example, all cables and interconnects contribute lower measured distortion than even the Halcro amplifiers, without exception, and yet many audiophiles claim to be highly aware of the difference between cables.
I am proud to have the unique claim stated above, namely that the Halcro amplifiers produce less false IM or harmonic signal than the measured threshold of the human ear.
In this industry, we are continually reminded that the ultimate test is the listening test.
I said exactly this sort of stuff way back in this thread, and now we have documented proof.
For you 'null testers', your amplifiers need to be as good as the Halcro to be indistiguishable, and if they are not, then the internal distortion products will be audible, and then by definition distinguishable.
0.01% amplifiers are distorted enough for the human ear to detect and categorise the distortions, especially IMD products.

I rest my case.

Eric.

Halcro, another Aussie world beater.
__________________
I believe not to believe in any fixed belief system.
 
Old 16th April 2003, 01:42 AM   #984
diyAudio Member
 
Tube_Dude's Avatar
 
Join Date: Mar 2002
Location: Aveiro-Portugal
Default The ultimate proof...

Quote:
now we have documented proof.
Quote:
For you 'null testers', your amplifiers need to be as good as the Halcro to be indistiguishable, and if they are not, then the internal distortion products will be audible, and then by definition distinguishable.
Ok... the publicity claims of a trade mark amplifiers staff...for you is a PROOF!!!

Quote:
I rest my case.
Me too!!
__________________
Jorge
 
Old 16th April 2003, 02:19 AM   #985
diyAudio Member
 
mrfeedback's Avatar
 
Join Date: Feb 2002
Location: Perth, Australia.
Default Text Book Explanations.

The noise power figures are given in the text.
Do yourself a favour and read and comprehend them.
IOW, a 70 dB null is not good enough to be inaudible.

Eric.
__________________
I believe not to believe in any fixed belief system.
 
Old 16th April 2003, 02:47 AM   #986
diyAudio Member
 
Tube_Dude's Avatar
 
Join Date: Mar 2002
Location: Aveiro-Portugal
Default What a pleasure.....to test the world "best"..

Quote:
Originally posted by mrfeedback
The noise power figures are given in the text.
Do yourself a favour and read and comprehend them.
IOW, a 70 dB null is not good enough to be inaudible.

What a pleasure if have a Halcro in my hands...and do the null test!!
It may become a big surprise....

Who knows???

Anyone have one???

Do it!!...do it!!!
__________________
Jorge
 
Old 16th April 2003, 04:02 AM   #987
diyAudio Member
 
Join Date: Nov 2002
Location: California
Quote:
Originally posted by Peter Daniel


Than I don't understand the reason for your comments in here (and the way you've made them).
As I said, anyone is free to believe what they wish. That doesn't mean that if they're spouting what I consider to be nonsense that I'm not going to say anything about it.

Quote:
And the comparison to flat Earth is pathetic at the least.
See, and that's how I feel about some of the stuff that people claim on these forums. Pathetic at the least. That aside, the point is that I couldn't imagine you'd advocate people teaching/advocating theories that are provably untrue. Yet, at the same time, I see this same thing all the time on these boards.
 
Old 16th April 2003, 05:28 AM   #988
diyAudio Member
 
Peter Daniel's Avatar
 
Join Date: Jul 2002
Location: Toronto, Canada
Send a message via AIM to Peter Daniel
Quote:
Originally posted by schmad


That aside, the point is that I couldn't imagine you'd advocate people teaching/advocating theories that are provably untrue. Yet, at the same time, I see this same thing all the time on these boards.

I'm not sure if I'm advocating those theories. But OTOH, I still didn't find a reason to believe they are not true so I prefer to believe they are true.

This gives me drive and enjoyment to do what I'm doing, and audio became a sort of an adventure to me. That's why I despise the people who spoil my fun. That's about it.
__________________
www.audiosector.com
“Do something really well. See how much time it takes. It might be a product, a work of art, who knows? Then give it away cheaply, just because you feel that it should not cost so much, even if it took a lot of time and expensive materials to make it.” - JC
 
Old 16th April 2003, 05:53 AM   #989
Account Disabled
 
Join Date: May 2002
Default Re: Worlds Cleanest Amplifier.

Quote:
Originally posted by mrfeedback
The only amplifier in the world to challenge a theoretical limit unprecedented harmonic distortion levels of less than 1000 parts per billion
Over the past 50 years it has taken the typical audio manufacturer 50 years to reduce distortion at 20kHz from .1% to .01%. Now, with a single revolutionary technological advancement, Halcro™ has reduced distortion to less than 0.0001%. In fact, all unpleasant distortion in the output stage has been virtually eliminated.



I said exactly this sort of stuff way back in this thread, and now we have documented proof.
For you 'null testers', your amplifiers need to be as good as the Halcro to be indistiguishable, and if they are not, then the internal distortion products will be audible, and then by definition distinguishable.
0.01% amplifiers are distorted enough for the human ear to detect and categorise the distortions, especially IMD products.

I rest my case.

Eric.

Halcro, another Aussie world beater.

...you are neither the first nor doubtless the last to be taken in by a manufacturer's sells blab.........to call such 'proof' is rather premature...

...tuned in readers will note that Cordell's amp. in JAES achieved the same level of THD+N some 20 years before DR. Candy's design..

...note also that Halcro's much vaunted low distortion is unconventionally specified without noise.......

...In practice and from steoreophiles measurements using Audio Precision equipment, THD+N is of the same order as that generated by the NE5534 driven to 10V peak output...namely 6ppm-8ppm across the audio band.........(not as earth shaking then as 600ppb!! ).....

also, according to Stereophile, the designer conceded that the 'sound quality' of his designs owed more to the quality of the power supply than anything else.....nothing new there then..
 
Old 16th April 2003, 06:08 AM   #990
Account Disabled
 
Join Date: May 2002
Default Re: DOUBLE BLIND DOUBLE DEAF.

Quote:
Originally posted by mikek
...so....if you 'agree with jc's approach', we can safely conclude that you 'agree' with his findings, and that therefore the majority of this thread has been a profound and an heroic waste of time?

Quote:
Originally posted by fdegrove
Hi,
It's not because I agree with this way to go about DBT that I agree with the heap of crap I read in this thread.

Any kind of measurement and testing is very useful, at the end of the day however it all depends on the intelligence of the person(s) interpreting the result(s) and how to draw conclusions from them.

Hope you can spot the difference?

Cheers,

AHH SOO!! ...you do 'agree' with his findings then!
 

Closed Thread


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



New To Site? Need Help?

All times are GMT. The time now is 04:12 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright ©1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2