Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

The Lounge A place to talk about almost anything but politics and religion.

John Curl's Blowtorch preamplifier part III
John Curl's Blowtorch preamplifier part III
John Curl's Blowtorch preamplifier part III 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
Reply
 
Thread Tools Search this Thread
Old 21st November 2018, 01:52 PM   #10021
mmerrill99 is offline mmerrill99
diyAudio Member
 
Join Date: Aug 2014
Quote:
Originally Posted by TNT View Post
mmerrill99, your are in the audio business - right? Did I recall correct that you have a website?

//
Ask Scottjoplin - he seems to think he knows all about me
  Reply With Quote
Old 21st November 2018, 01:57 PM   #10022
Markw4 is offline Markw4  United States
diyAudio Member
 
Join Date: Jul 2016
Location: California
Quote:
Originally Posted by PMA View Post
Such report and the signature check makes at least some proof that the test was not cheated by file modification etc., as it is a long-distance test.
Such a statement is too vague for scientific work. You need to determine a way to weight the probability of cheating. Otherwise, a biased experimenter is free to invoke the excuse at will. There needs to be an objective basis for evaluating it as an influencing factor on outcomes. IMHO, of course.

Last edited by Markw4; 21st November 2018 at 02:00 PM.
  Reply With Quote
Old 21st November 2018, 02:00 PM   #10023
PMA is offline PMA  Europe
diyAudio Member
 
PMA's Avatar
 
Join Date: Apr 2002
Location: Prague
So do you have a better suggestion, if we sit thousands miles apart?
__________________
Pavel Macura http://pmacura.cz/audiopage.html
  Reply With Quote
Old 21st November 2018, 02:23 PM   #10024
cliffforrest is offline cliffforrest  United Kingdom
diyAudio Member
 
Join Date: Sep 2004
Location: South Coast, UK
Quote:
Originally Posted by mmerrill99 View Post
@DF96, your pedantry is getting tedious for everybody, I suspect so I'l keep it short?
No it is not. Only less than a dozen contributors here so your hyperbole is silly.

From my tiny corner of the world your input is becoming a PITA.
  Reply With Quote
Old 21st November 2018, 02:23 PM   #10025
DF96 is offline DF96  England
diyAudio Member
 
Join Date: May 2007
Quote:
Originally Posted by mmerrill99
@DF96, your pedantry is getting tedious for everybody, I suspect so I'l keep it short?
When I do it it is tedious pedantry. When you do it it is merely attention to detail. Did I get that right?

Quote:
So you proffer no definition of what is a "reasonable" unsighted test to you
Yes, I offer no definition. Any definition I offer will be carefully picked over for flaws, which will then be held aloft with a triumphant cry. In life we do not have to rigourously define every word we use. Most reasonable people know what the word 'reasonable' means. No definition could possible cover all possible unreasonable tests, because there is no limit to the foolishness of others.

Quote:
Originally Posted by scottjoplin
Bet he won't answer
I seem to recall inviting him to comment on this before, some months ago, but he declined and tried to divert the discussion. I may be wrong; it could have been someone else.

Quote:
So tell us how you know the unsighted test isn't just comprising of false negative results or are you not concerned about that, only wishing to minimize false positives?
A reasonable test would not be strongly biased either way. I expect you will now ask me to define 'strong bias'. It could be tortoises all the way down.
  Reply With Quote
Old 21st November 2018, 02:30 PM   #10026
DF96 is offline DF96  England
diyAudio Member
 
Join Date: May 2007
Quote:
Originally Posted by DF96
. . he declined and tried to divert the discussion
Quote:
Originally Posted by mmerrill99
Ask Scottjoplin - he seems to think he knows all about me
The right to remain silent is present in many jurisdictions. People, including juries, make of this what they will.
  Reply With Quote
Old 21st November 2018, 02:34 PM   #10027
KSTR is offline KSTR  Germany
diyAudio Member
 
KSTR's Avatar
 
Join Date: Jul 2007
Location: Central Berlin, Germany
Quote:
Originally Posted by gpapag View Post
I have asked myself a relevant question though on this point.
When I am to arrange such a comparative test: In case one of the DUTs changes the dynamic range appreciably (>1-2dB), either due to increased noise floor or due to smooth compression of the high level peaks or both, what instrument reading should I use for to level equalize the two files (target is equal perceived level of loudness)?
Peak hold, VU peak, average RMS power?
A resonable baseline would be to set the level so that the waveform difference (after time-alignment) during low volume passages is minimal (as measured and by listening to the residual) as we would assume distortion is lowest at low levels. At high level, in the 1% THD range, there will be deformation of the peaks, any combination of expanding or compressing peaks of individual polarity may occur so no way to level-align this with peak-hold values or RMS during louder passages. The larger the distortion and the more dynamic the recording the lesser one can match levels... which section of the file to choose for the statistics? Do we want same percieved loudness during low level passages or during (very occassional) lound bursts? One could make histogramms of short-term (200ms) rms value bins and then concentrate on the passages with many blocks in/near the distribution peak and level-align using those sections, to get a sort of weighted average level trimming.
  Reply With Quote
Old 21st November 2018, 02:34 PM   #10028
mmerrill99 is offline mmerrill99
diyAudio Member
 
Join Date: Aug 2014
Quote:
Originally Posted by DF96 View Post
When I do it it is tedious pedantry. When you do it it is merely attention to detail. Did I get that right?
Your refusal to deal with the detail & repeat the same mantra is what is tedious.


Quote:
Yes, I offer no definition. Any definition I offer will be carefully picked over for flaws, which will then be held aloft with a triumphant cry. In life we do not have to rigourously define every word we use. Most reasonable people know what the word 'reasonable' means. No definition could possible cover all possible unreasonable tests, because there is no limit to the foolishness of others.
You hold no expectation of the quality of a test, you simply judge it as it comes, play it by ear, i.e. make it up as you go along

Quote:
I seem to recall inviting him to comment on this before, some months ago, but he declined and tried to divert the discussion. I may be wrong; it could have been someone else.

A reasonable test would not be strongly biased either way. I expect you will now ask me to define 'strong bias'. It could be tortoises all the way down.
How do you know a test is "strongly biased" - just your 'belief system', again at play?
  Reply With Quote
Old 21st November 2018, 02:35 PM   #10029
PMA is offline PMA  Europe
diyAudio Member
 
PMA's Avatar
 
Join Date: Apr 2002
Location: Prague
Quote:
Originally Posted by TNT View Post
mmerrill99, your are in the audio business - right? Did I recall correct that you have a website?

//
It took me sometime, yes there is a Merrill Audio site

Element 118 Power amplifier Monoblocks

Quote:
Merrill Audio Advanced Technology Labs, LLC was founded with the singular mission of High Value Audio and Audio Purity. We are focused on audio and not price points. We are focused on customer service that will delight you.
They use highend components like
Quote:
The element 118 Power Amplifier Monoblocks only use stranded wire that is OFC, silver plated and sleeved in Teflon and was selected for its low parasitics impedance and dielectric characteristics. High Gauge wire is the norm throughout and every audio signal path is hand soldered to provide the purest possible connection.
and I think they mention a GHz BW somewhere.

Quote:
Using the most advanced and newest Gallium Nitride transistors available, the Element 118 Power Amplifier Monoblocks are capable of delivering speeds into the Gigahertz range.
__________________
Pavel Macura http://pmacura.cz/audiopage.html

Last edited by PMA; 21st November 2018 at 02:39 PM.
  Reply With Quote
Old 21st November 2018, 02:36 PM   #10030
mmerrill99 is offline mmerrill99
diyAudio Member
 
Join Date: Aug 2014
Quote:
Originally Posted by DF96 View Post
The right to remain silent is present in many jurisdictions. People, including juries, make of this what they will.
If you can't deal with the logic of the arguments & have to revert to trying to bait the person, then many readers make of this what they will.
  Reply With Quote

Reply


John Curl's Blowtorch preamplifier part IIIHide this!Advertise here! John Curl's Blowtorch preamplifier part III
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

Forum Jump


New To Site? Need Help?

All times are GMT. The time now is 05:49 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Copyright ©1999-2019 diyAudio
Wiki