John Curl's Blowtorch preamplifier part II - Page 4856 - diyAudio
Go Back   Home > Forums > Member Areas > The Lounge

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

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 24th February 2014, 04:14 PM   #48551
PMA is offline PMA  Europe
diyAudio Member
 
PMA's Avatar
 
Join Date: Apr 2002
Location: Prague
Quote:
Originally Posted by SY View Post
It's actually wire burn-in that they neglected,
Definitely!!!
Or rather ear burn-in.
__________________
Pavel Macura
http://web.telecom.cz/macura/audiopage.html
  Reply With Quote
Old 24th February 2014, 04:14 PM   #48552
diyAudio Member
 
john curl's Avatar
 
Join Date: Jul 2003
Location: berkeley ca
Thanks vacuphile, that was the most reasonable answer as to why the Hubble was compromised from the get-go that I have ever heard.
  Reply With Quote
Old 24th February 2014, 04:17 PM   #48553
diyAudio Member
 
scott wurcer's Avatar
 
Join Date: Jan 2004
Location: cambridge ma
Quote:
Originally Posted by VladimirK View Post
but there are several references in the list of references, about this subject, published in english.
Yes, one on operation in space in the presence of ionizing gamma radiation.
__________________
"The question of who is right and who is wrong has seemed to me always too small to be worth a moment's thought, while the question of what is right and what is wrong has seemed all-important."
  Reply With Quote
Old 24th February 2014, 04:32 PM   #48554
hhoyt is offline hhoyt  United States
diyAudio Member
 
hhoyt's Avatar
 
Join Date: Mar 2010
Location: Chapel Hill, NC
Default Amp Degradation

Quote:
Originally Posted by Max Headroom View Post
In line with my mention of initial 'burn-in', I have also found that an amp can permanently change for the worse subjectively by being temporarily pushed too far into very hard clipping.

Dan.
Good call, I have repaired a couple of amps where the feedback or output stage resistors were overheated and had changed value, probably caused by extended operation at high power.

Howie

Howard Hoyt
CE - WXYC-FM 89.3
UNC Chapel Hill, NC
www.wxyc.org
  Reply With Quote
Old 24th February 2014, 04:33 PM   #48555
diyAudio Member
 
Kindhornman's Avatar
 
Join Date: Aug 2012
Location: Los Angeles, California
vacuphile,
They don't need spy satellites these days, they just turn on your camera in your phone while you don't know it and can see where you are and with the GPS tracking you are toast!
  Reply With Quote
Old 24th February 2014, 04:33 PM   #48556
diyAudio Member
 
Join Date: Feb 2007
Location: Tashkent
Quote:
Originally Posted by scott wurcer View Post
Yes, one on operation in space in the presence of ionizing gamma radiation.
Yes, the paper says, that if defects have been produced somehow (one possibility is by gamma-radiation in space) than some pulses of alternating currents help to restore the damaged structure. How is it applicable to metallization in caps or to resitive films - do find analogies.

Here is my translation of short part from the paper:

"Efficient annealing of radiation- induced charges in the gate oxide material
and at the interface of Si-SiO2 is due to complex thermal and injection
effects of the alternating current flowing through the device structure .
Vibrational
movement of free carriers increases the probability of neutralization of trapping centers in the
insulator and at the insulator -semiconductor interface [1]. Free carriers
transfer energy to the crystal lattice and especially to defect centers with broken
bonds, causing an increase in the lattice vibrations and creation of local displacements in the lattice.
As a result, the lattice tends to occupy the state with the lowest energy."

Defects and their annealing in solids were a part of my former professional career, and Mr RNMarsh probably is well awared of what has been studied by computer simulation group at LLNL.

Last edited by VladimirK; 24th February 2014 at 04:45 PM.
  Reply With Quote
Old 24th February 2014, 04:44 PM   #48557
diyAudio Member
 
john curl's Avatar
 
Join Date: Jul 2003
Location: berkeley ca
Vlad, my reference is: "ELECTRON MICROSCOPY OF INTERFACES IN METALS AND ALLOYS' by C T Forward and LM Clarebrough pp 314-325.
"6.4.1 Faulted Defects generated by the Movement of Boundaries in Electron Microscope Specimens"
This is viewing 99.999% Cu at room temperature and watching it at intervals with an electron microscope, and find it move things around to 'decrease its overall energy'.

Last edited by john curl; 24th February 2014 at 04:52 PM.
  Reply With Quote
Old 24th February 2014, 04:52 PM   #48558
diyAudio Member
 
scott wurcer's Avatar
 
Join Date: Jan 2004
Location: cambridge ma
Quote:
Originally Posted by john curl View Post
Thanks vacuphile, that was the most reasonable answer as to why the Hubble was compromised from the get-go that I have ever heard.
The post mortem report is public record, as usual more complicated than one thinks.

http://www.ssl.berkeley.edu/~mlampto...nReportHST.pdf
__________________
"The question of who is right and who is wrong has seemed to me always too small to be worth a moment's thought, while the question of what is right and what is wrong has seemed all-important."
  Reply With Quote
Old 24th February 2014, 05:04 PM   #48559
diyAudio Member
 
jneutron's Avatar
 
Join Date: Jan 2004
Location: away
Quote:
Originally Posted by john curl View Post
No, not me JN, you.
Alas, I'm not the one who said 'evidence'. You are.

It's very clear that you at least now understand anecdotal evidence for what it is.

When you present scientifically verifiable evidence to the table, I will be the first to listen.

Hand-waving and condescension, your normal 'evidence', is casually dismissed.

Your circuit discussions, I listen.

jn
  Reply With Quote
Old 24th February 2014, 05:20 PM   #48560
diyAudio Member
 
john curl's Avatar
 
Join Date: Jul 2003
Location: berkeley ca
Sorry, its FORWOOD, not Forward. Look it up, those of serious interest in this.
  Reply With Quote

Reply


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 02:39 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