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kimwah
Joined: 05 Aug 2005 Posts: 2
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02 Jul 2009 13:34 earphone to line level |
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| Hi pals I have a casseete radio player which have no 'line out' output terminal it has only a earphone output terminal. I need it so I can connect it to my line-in of my computer. I wanted to know whether it could be modify so it have a line-out terminal. I do hope someone can help me to do it. Thanks.
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banjo
Joined: 24 Dec 2005 Posts: 644 Helped: 117
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03 Jul 2009 2:28 hobby earphone |
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Line level for consumer audio is about 0.3V rms. You would need to replace the volume control with a fixed resistor divider that produces this 0.3V rms during normal to loud sounds.
If the audio controls in your computer list the decibel levels of the inputs, you could just fiddle with the volume control of the radio until the average level was about -10dBV. Then mark the volume control position at that level as a reference of where to set it to obtain approximate line levels.
If you want to do everything external to your radio, you would need an external resistor divider and you would have to remember to set the volume control to maximum. With the volume at max, the resistor divider would do the scaling back to line levels. Since radio output impedances and levels vary, you would have to do some experimenting to find the appropriate resistor divider.
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kimwah
Joined: 05 Aug 2005 Posts: 2
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03 Jul 2009 6:50 volume control earphone resistor |
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| Thanks banjo I am a bit confuse of what you have mentioned. Do you mean I have to add a new volume control in the radio-casseete player. I wish to have a new terminal for 'line out' as modern casseete player have, is it possible to modify it. If you think it is poissible please let me have a circuit for it. I will also be much appreciate if you can show me a circuit for the earlier mentioned vol. control. Thanks again for your help.
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