I have recently purchased a car radio to install in my camper van. Supplied with the radio is an adapter that attaches to the rear of the unit and is labeled 2v line out - the adapter is fitted with a red and white RCA male jacks. I am able to buy a connector two female RCA to 3.5mm headphone jack. Using such a connector is it OK to use this setup to listen to the radio with headphones?
Thank you.
Thank you.
I can't get a model number from that site.
No model number...no manual.
I could only guess that you would need a small amplifier that has a volume control.
Depending on the quality you are looking for a small computer speaker set would probably be enough...something that runs on 12V-14V.
Any information in the manual?
No model number...no manual.
I could only guess that you would need a small amplifier that has a volume control.
Depending on the quality you are looking for a small computer speaker set would probably be enough...something that runs on 12V-14V.
Any information in the manual?
Thank you for your reply.
The model no is the same as the catalog no, QM3781.
The manual gives little help, it has no information on the line out. It does indicate a suitable speaker impedance is 4-8 ohms. As I understand it the impedance of the line out in such a radio may be several hundred ohms which would mean that there would be an unacceptable mismatch between the line out and connected headphones.
It may be possible to connect the headphones to the speaker outputs but I am not sure of the correct way to do this.
The model no is the same as the catalog no, QM3781.
The manual gives little help, it has no information on the line out. It does indicate a suitable speaker impedance is 4-8 ohms. As I understand it the impedance of the line out in such a radio may be several hundred ohms which would mean that there would be an unacceptable mismatch between the line out and connected headphones.
It may be possible to connect the headphones to the speaker outputs but I am not sure of the correct way to do this.
Why headphones instead of speakers?
The impedance of headphones varies greatly. Some may work well enough when driven by the RCA outputs, depending on the output level required.
The speaker level output appears to be bridged so you'd have to be very careful if you decide to use that to drive the headphones.
The output will have 1/2 B+ on every speaker wire. Allowing any output wire to ground will very likely destroy the internal amplifier.
You could isolate the DC with capacitors but you'd then have the problem of a ground. The headphones would likely have a single/common ground but the left and right channels would have independent grounds. You would have to select the left OR the right ground to use for the headphone ground.
The level would be more than most headphones would need so you'd likely have to fade away from the speaker outputs that you're using to get the volume control to be usable through most of its range.
The impedance of headphones varies greatly. Some may work well enough when driven by the RCA outputs, depending on the output level required.
The speaker level output appears to be bridged so you'd have to be very careful if you decide to use that to drive the headphones.
The output will have 1/2 B+ on every speaker wire. Allowing any output wire to ground will very likely destroy the internal amplifier.
You could isolate the DC with capacitors but you'd then have the problem of a ground. The headphones would likely have a single/common ground but the left and right channels would have independent grounds. You would have to select the left OR the right ground to use for the headphone ground.
The level would be more than most headphones would need so you'd likely have to fade away from the speaker outputs that you're using to get the volume control to be usable through most of its range.
Perry, I was hoping to have the option of listening to the radio through speakers or through headphones.
I was wanting to connect the headphones through the line out connection. You have indicated the alternative and the problems with a speaker connection (i have only the two front seakers connected) so I will carefully read the links given in your post to determine if I have the skills to make that connection - I certainly do not want to damage the readio amp.
I was wanting to connect the headphones through the line out connection. You have indicated the alternative and the problems with a speaker connection (i have only the two front seakers connected) so I will carefully read the links given in your post to determine if I have the skills to make that connection - I certainly do not want to damage the readio amp.
You can if it's done with capacitors and you use one of the two speaker negatives for the headphone ground.
You could run the preamp outputs into a dedicated headphone amp. The problem with using the preamp outs, though, is that the sound will also continue to play through the speakers.
It may be possible to switch the speaker level outputs to line-level converters. The fader could be used so only the front or rear would need a switch. Feed that converted output to the headphone amp.
It may be possible to switch the speaker level outputs to line-level converters. The fader could be used so only the front or rear would need a switch. Feed that converted output to the headphone amp.
Thanks all for your help. It seems, especially with my limited skills, the best solution would be to look for an inexpensive amp, with volume control and headphone jack, that could be connected to the rear line out. May also need to include a switch to turn off front speakers when headphones are being used.
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