Lightspeed Attenuator a new passive preamp - Page 506 - 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 19th June 2013, 12:08 PM   #5051
diyAudio Member
 
Audionutz's Avatar
 
Join Date: Jun 2006
Quote:
Originally Posted by soongsc View Post
Even the layout of the app looks different.
Its a Screenshot of the Stereophile Recommended Components 2013 App. You can get it at the App Store free.

Cheers

'Nutz
__________________
The Future is not what it used to be .....
  Reply With Quote
Old 23rd June 2013, 12:17 PM   #5052
scm is offline scm  United States
diyAudio Member
 
Join Date: Jun 2007
Guys..I have a question about the Lightspeed Attenuator.
What would cause the volume control to become inoperative ??
Here`s a little background to this question.

Seems a gentleman had a problem with his Lightspeed, apparently it had a channel imbalance and he sent it back to George for repair .
According to him, George put a new set of LDRs and fixed the imbalance issue.

He said it worked fine for a few weeks then last Monday it got way too loud with the volume knob having no effect at all.
Seems it`s FULL volume ALL the time.

Not wanting to send it all the way back to George again, he decided to sell it.

I`m awaiting its arrival in a couple of days and am needing some ideas on what I might look for or do to hopefully fix it.

Any ideas ??
  Reply With Quote
Old 23rd June 2013, 01:31 PM   #5053
udailey is offline udailey  United States
diyAudio Member
 
Join Date: Mar 2008
measure resistance from output to ground with cct on. Shunt ldrs seem dead.
Uriah
__________________
purchase LDRs anytime Also try my Resistor Replacers or LDR based Input Selector Email me. diyldr@gmail.com
  Reply With Quote
Old 23rd June 2013, 01:55 PM   #5054
scm is offline scm  United States
diyAudio Member
 
Join Date: Jun 2007
So would it need another whole new set of 4 LDR`s.
The seller stated that it cost him a little over $200.00 !

I certainly hope I don`t need to go that route.
I understand this is a DIY Forum but I really am a complete know nothing and I don`t know what is meant by your statement...sorry.

I do appreciate any and all help though, so I`ll try and learn enough to get me through this.

Thanks
Steve
  Reply With Quote
Old 23rd June 2013, 02:43 PM   #5055
wlowes is offline wlowes  Canada
diyAudio Member
 
wlowes's Avatar
 
Join Date: Mar 2007
Location: Toronto
Blog Entries: 9
Start by measuring all the voltages into the LDR. If there is no voltage going to the shunt ldr, they will be at 1Mohm and you'd have a very little attenuation regardless of what is going on with the series ldr. If both channels are loud, sounds more likely power not going to that half the circuit than both ldrs being blown. Could just be a single broken wire or a bad solder joint. Likely cost you nothing. If you paid very little you are likely to get a great deal. If the ldrs are dead then yes you need to replace them all. Still not a big deal.
  Reply With Quote
Old 23rd June 2013, 02:44 PM   #5056
udailey is offline udailey  United States
diyAudio Member
 
Join Date: Mar 2008
Right. More likely than bad ldrs is that ground is no longer attached. No signal ground or no power ground to shunts would have the same result.
__________________
purchase LDRs anytime Also try my Resistor Replacers or LDR based Input Selector Email me. diyldr@gmail.com
  Reply With Quote
Old 23rd June 2013, 03:35 PM   #5057
scm is offline scm  United States
diyAudio Member
 
Join Date: Jun 2007
What do I look for once I 'Pop the Hood' ??
  Reply With Quote
Old 23rd June 2013, 07:10 PM   #5058
udailey is offline udailey  United States
diyAudio Member
 
Join Date: Mar 2008
Check the signal ground wires for loose connection or broken. I fixed a lightspeed for a guy and the signal ground wire had come loose. I bet its something like that. If you have a multimeter you can test for continuity between the outer shell of each rca and the signal ground on each ldr and also check for continuity from 0V on the power supply to the leads at the bottom of the LDRs if they are visible but they are probably in a block of wax.
__________________
purchase LDRs anytime Also try my Resistor Replacers or LDR based Input Selector Email me. diyldr@gmail.com
  Reply With Quote
Old 23rd June 2013, 08:16 PM   #5059
scm is offline scm  United States
diyAudio Member
 
Join Date: Jun 2007
Thanks..once I have it in hand I`ll dig around a bit.

Steve
  Reply With Quote
Old 23rd June 2013, 10:23 PM   #5060
diyAudio Member
 
georgehifi's Avatar
 
Join Date: Sep 2003
Location: Manly Australia (Jewel of the Pacific)
Send a message via MSN to georgehifi
If this is the one I remember, it came to me and when I opened it the only words that came to me was "who buchered this" with trying different mods.
From what you've been saying about the fault it's got, first off replace the 100ohm dual log volume pot, as it sounds to me that the shunt ldr side of it has gone open circuit, they can be got for under $10. Take a pic of the way it is wired and wire the new one the exact same way.

Cheers George
__________________
Avatar : Production Lightspeed Attenuator
www.lightspeedattenuator.com
  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 02:20 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