Can this be done? - diyAudio
Go Back   Home > Forums > General Interest > Car Audio

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 31st May 2006, 02:56 AM   #1
Wombat2 is offline Wombat2  Australia
diyAudio Member
 
Wombat2's Avatar
 
Join Date: Nov 2003
Location: Brisbane
Default Can this be done?

Would this arrangement cause any problems? Car radio/cassette player and a separate CD player feeding into the same set of speakers. Both units are power up when the ignition is on but only one playing at any one time.

Reason I ask is this arrangment has been working OK for about 6 mths but recently playing a tape and the CD player let out the magic smoke.
__________________
David L
  Reply With Quote
Old 31st May 2006, 06:31 AM   #2
lndm is offline lndm  Australia
diyAudio Member
 
Join Date: Mar 2006
Location: nsw
I once tried to bridge both channels of a stereo amp by soldering their outputs together. They died before I could even connect a source. I would definately use a line level connect from one component to the main component, or use a buffer amp.

Just guessing, there may have been a tiny DC offset between the channels, but with almost zero resistance between them, they would have passed current until they passed out.
  Reply With Quote
Old 31st May 2006, 08:38 AM   #3
sreten is offline sreten  United Kingdom
diyAudio Member
 
Join Date: Nov 2003
Location: Brighton UK
Hi,

Simple answer is no it should not be done.
Something will rapidly or eventually blow.
The active amplifier is driving the inactive amplifier as a virtual short.
Power output for both amplifiers will be poor.

/sreten.
  Reply With Quote
Old 31st May 2006, 12:53 PM   #4
Wombat2 is offline Wombat2  Australia
diyAudio Member
 
Wombat2's Avatar
 
Join Date: Nov 2003
Location: Brisbane
Thanks - not what I wanted to hear but what I needed to hear
__________________
David L
  Reply With Quote
Old 31st May 2006, 06:49 PM   #5
Stocker is offline Stocker  United States
diyAudio Member
 
Join Date: Dec 2003
Location: Austin
easy solution, not cheap but easy, is to buy a head unit with tape and CD

or get a portable CD player and put it to the line level input of the tape headunit
__________________
Jesus loves you.
  Reply With Quote
Old 1st June 2006, 04:14 AM   #6
diyAudio Member
 
Join Date: Nov 2003
Location: Louisiana
You can use relays to switch between sources. If you use common Bosch relays, you will need to use 1 relay per speaker wire.

Pin 30 - speaker terminal
Pin 87a - the default source unit
Pin 87 - the alternate source unit

85/86 switched power/ground to the relays. You may be able to use the remote turn on of the alternate source to switch the relays but 4 relay coils may burn out the remote driver transistor. You could switch the relays with a toggle switch or use a 5th relay to buffer the remote output of the alternate source.
  Reply With Quote
Old 1st June 2006, 02:56 PM   #7
diyAudio Member
 
Join Date: Jun 2005
Location: BAY AREA, CA.
Send a message via AIM to IMPALAMAN1
very nice Perry. Is there a limit on the amount of power you can put through the relay?
__________________
linear power/ oz audio/ clarion
  Reply With Quote
Old 10th June 2006, 06:21 PM   #8
diyAudio Member
 
Join Date: Nov 2004
Location: sk
Send a message via AIM to ocool_15 Send a message via Yahoo to ocool_15
yes, but they are marked on them and a regular 12V 30A relay is more then enough. A 12V relay at 3A or larger is adequate
  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 08:09 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