Replace display bulb with LED on NAD cd players - diyAudio
Go Back   Home > Forums > Source & Line > Digital Source

Digital Source Digital Players and Recorders: CD , SACD , Tape, Memory Card, 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 7th September 2009, 11:40 PM   #1
Mikelo is offline Mikelo  Antarctica
diyAudio Member
 
Join Date: Feb 2004
Location: Colorado, Oregon
Default Replace display bulb with LED on NAD cd players

I have been replacing the bulbs on a NAD 502
and a 512 display, but they burn out every couple of
years and would like to replace the incandescent
bulbs with LEDs. I tried an intuitive approach
and used a LED with the appropriate resistor
between anode and the 15 volts, but that did
not work. Somewhere online I saw that to do
this you also need a capacitor and a diode.

Any hints, advice, links, diagrams, etc. would
be very much appreciated.
  Reply With Quote
Old 8th September 2009, 12:35 AM   #2
amc184 is offline amc184  New Zealand
diyAudio Member
 
amc184's Avatar
 
Join Date: May 2007
Location: Christchurch
I've replaced the bulbs on a NAD 705 with LEDs successfully. That was as simple as a LED and a dropper resistor to replace each bulb.

However, the bulb supply on a NAD 705 is DC, and if people were talking about putting a capacitor in the mix, the 502 and 512 may use an AC bulb supply.

Check whether the bulb supply is AC or DC, and we'll be able to help you further.
  Reply With Quote
Old 8th September 2009, 01:20 AM   #3
diyAudio Member
 
Join Date: Mar 2002
Location: Canada
If your 15v is DC(and presume your bulbs is 12V) just use diodes string each one drop about .6v , if AC go with .25/.50 ohm 10w to drop around 12V.
__________________
Praudio
  Reply With Quote
Old 8th September 2009, 03:50 AM   #4
Mikelo is offline Mikelo  Antarctica
diyAudio Member
 
Join Date: Feb 2004
Location: Colorado, Oregon
Is it possible that the resistor was too high? I was using a 560
ohm resistor. But it turns out it was a 30mA, 5V led, which means
given that the supply is 15vdc I need a 336 ohm resistor.
  Reply With Quote
Old 20th September 2009, 03:04 PM   #5
Bill_P is offline Bill_P  United States
diyAudio Member
 
Join Date: Sep 2009
Location: New York, the vampire state
Quote:
Originally Posted by Mikelo View Post
Is it possible that the resistor was too high? I was using a 560
ohm resistor. But it turns out it was a 30mA, 5V led, which means
given that the supply is 15vdc I need a 336 ohm resistor.
I found the service manuals for the 502 and 512 on the web. Both schematics show two 16V incandescent bulbs connected in parallel and fed from -15VDC, not +15VDC. You probably have the LED(s) connected backwards if you were expecting a +15VDC source.

Regarding the LED, 30mA seems high - what LED are you planning to use? It should still light up with 560 Ohms in any case. I would wire the LED's in series with an appropriate resistor to set the current to the recommended value from the datasheet.
  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


Similar Threads
Thread Thread Starter Forum Replies Last Post
replace ceramic resonator with quartz crystal in cheaper CD players wa2ise Digital Source 26 30th December 2005 02:42 AM


New To Site? Need Help?

All times are GMT. The time now is 05:52 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