Lightspeed Attenuator a new passive preamp - Page 335 - diyAudio
Go Back   Home > Forums > Source & Line > Analog Line Level

Analog Line Level Preamplifiers , Passive Pre-amps, Crossovers, etc.

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 8th July 2010, 01:36 AM   #3341
diyAudio Member
 
Join Date: Nov 2008
Quote:
Originally Posted by udailey View Post
I have sent them ... a handful of junk LDRs to prove my point that their datasheets are not sound and that their manufacturing suffered when they changed manufacturing plants but they just try to steer me to using other optoresistors they make.

Uriah
If none are "typical" how do you define a "junk" LDR?
  Reply With Quote
Old 8th July 2010, 02:21 AM   #3342
tinitus is offline tinitus  Europe
diyAudio Moderator R.I.P.
 
Join Date: Nov 2005
that was quite funny, and out of order
__________________
sometimes we know very little, and sometimes we know too much
  Reply With Quote
Old 8th July 2010, 10:53 AM   #3343
diyAudio Member
 
Join Date: Nov 2008
Quote:
Originally Posted by tinitus View Post
that was quite funny, and out of order
Huh? Have I been misunderstood? Not sure if this is directed at my post or not, but it seems like it was . . .

If you are in fact referring to my question about "junk" LDRs, it was an honest question, intended to elicit an answer to "When should one reject an LDR as unusable for this purpose?" and if Uriah is willing, I'd like to hear the answer. If you're talking about another post entirely, sorry for my confusion and please disregard this post.

BTW I'm totally new around here, don't want to step on any toes -- please tell me what was out of order, because I honestly can't see it.
  Reply With Quote
Old 8th July 2010, 10:59 AM   #3344
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
Some of our Members think they have a sense of humour.

Their off topic posts with no reference to what they should be talking about should be banned.

I shall report the off topic post to the Moderator team.
__________________
regards Andrew T.
  Reply With Quote
Old 8th July 2010, 12:34 PM   #3345
tinitus is offline tinitus  Europe
diyAudio Moderator R.I.P.
 
Join Date: Nov 2005
Quote:
Originally Posted by wapo54001 View Post

please tell me what was out of order, because I honestly can't see it.
I thought you meant that "junk" seemed typical, in reply to udailey saying that theres no "typical" LDR

Maybe I have misunderstood you
__________________
sometimes we know very little, and sometimes we know too much
  Reply With Quote
Old 8th July 2010, 05:30 PM   #3346
udailey is offline udailey  United States
diyAudio Member
 
Join Date: Mar 2008
I think its a fine question. I have two different times I use the term Junk LDR. The Junk LDRs I sent to Silonex were the type that when you get them and test them they are TOTALLY screwed up. Like testing their minimum and getting 1k and at the same power that a good LDR would show 10k the Junk LDRs show 300k. So I sent those off.
Junk LDRs, like the ones I sell for cheap on my site are those that I have tested that have rather 'normal' ranges but that dont match any other LDR and they have been through two rounds of testing against 920 different LDRs. They are obviously useful as a single LDR but also will obviously never match another LDR and are useless to me. Some people buy them just to screw around experimenting. A good place to use these would be the input resistor on an amp. The Rf on a current feedback amp. An input switcher, etc. Places where only one resistor is needed and where a low value such as 100-10k is needed.
Keep asking questions as long as you need to. You may be new but you are not stepping on toes and I dont think Tinitus thought anything was wrong with your post.
Uriah
__________________
purchase LDRs anytime Also try my Resistor Replacers or LDR based Input Selector Email me. diyldr@gmail.com
  Reply With Quote
Old 8th July 2010, 06:16 PM   #3347
tinitus is offline tinitus  Europe
diyAudio Moderator R.I.P.
 
Join Date: Nov 2005
Quote:
Originally Posted by udailey View Post
You may be new but you are not stepping on toes and I dont think Tinitus thought anything was wrong with your post.
Uriah
Nah, then you would definately know, and have felt it, unmistakenly

The mod job can be difficult at times, but the worst to me is that it also tend to make it even harder to just be an ordinary member
And being a member will always be my main preference

Now thats said, lets not waste more time on this small misunderstanding
__________________
sometimes we know very little, and sometimes we know too much
  Reply With Quote
Old 9th July 2010, 06:58 AM   #3348
drwkng is offline drwkng  Hong Kong
diyAudio Member
 
Join Date: Jun 2004
Location: Hong Kong
i thought i'm the only person who have problems with these LDR. i use them for input switching and not attenuation. unfortunately they just randomly change in resistance or die prematurely. i told Silonex the problem and they said i'm the only one having this problem. so much for Silonex and i still have a few hundred lying around doing nothing!
  Reply With Quote
Old 9th July 2010, 12:38 PM   #3349
diyAudio Member
 
Join Date: Nov 2008
Quote:
Originally Posted by drwkng View Post
i thought i'm the only person who have problems with these LDR. i use them for input switching and not attenuation. unfortunately they just randomly change in resistance or die prematurely. i told Silonex the problem and they said i'm the only one having this problem. so much for Silonex and i still have a few hundred lying around doing nothing!
Good grief, between the two of you, one wonders if this device is worth designing around.

An unsatisfactorily high rate of out-of-tolerance rejects is not good, but if you're suffering a high rate of in-circuit failures, that is not OK. Are you driving them beyond the 20ma-40R specification? The randomly changing resistance sounds the same as Uriah's reason for avoiding sustained high current operation.
  Reply With Quote
Old 9th July 2010, 12:46 PM   #3350
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
Default LED/LDR reliability

and yet George HiFi finds that his (customer) versions rarely if ever fail and stay in channel balance in the long term.

What are we doing different that we end up with all these conflicting reports?
__________________
regards Andrew T.
  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 09:52 AM.


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