[Tutorial] Upgrading OEM Clarion Digital Tuner / EQ stack
03-27-16, 11:46 PM
#26
I pulled some components out of the car and did some more bench testing.
1) Amps - these are fine, produce clean sound when given a decent signal. I ran my home speakers off them and the output was louder than expected. However that may be because sending signal from my iPhone is higher voltage than the factory radio.
2) Head unit. Passing pink noise through the head unit is relatively flat. If you tap in the way you are doing things I see no issue.
3) How things work....
The radio and tape deck are essentially separate units which produce their own low voltage signal that is sent to the external amps. When the tape deck turns on, it cuts power to the radio module. You seemed to have missed this part in your tutorial.
On the tuner: The single pin connector is constant 12v power for station memory and operating power. Pin C of the 3 pin connector is acc 12v power. The radio gets power via the tape deck.
On the tape deck: Pin C of the 6 pin connector is acc 12v power for operation. Pin B is pass through acc 12v power and connects to pin C of the tuner. The connection between pin C and pin B is normally open so the tuner works. When you insert a cassette the connection is closed and the radio loses power. The lights on the radio still work because they get power from illumination. The volume, bass, fader work because those are just inline with the audio signal and nothing else. So the tuner is essentially turned off when you insert the tape.
With that knowledge, here's how you eliminate "ghost signal". De-pin the 3-pin connector to the radio and place a SPDT relay inline with pin C. Make sure you use 87a on the relay so the radio gets power when the relay is deactivated. Place a switch somewhere to activate the relay when you are ready to use the AUX input. To be really clever, you can use a 1/8" chassis mount jack that has a built in switch that is activated when someone inserts a cord. It will ground out and cause the relay to activate. You might even be able to install something like that on the face of the radio.
1) Amps - these are fine, produce clean sound when given a decent signal. I ran my home speakers off them and the output was louder than expected. However that may be because sending signal from my iPhone is higher voltage than the factory radio.
2) Head unit. Passing pink noise through the head unit is relatively flat. If you tap in the way you are doing things I see no issue.
3) How things work....
The radio and tape deck are essentially separate units which produce their own low voltage signal that is sent to the external amps. When the tape deck turns on, it cuts power to the radio module. You seemed to have missed this part in your tutorial.
On the tuner: The single pin connector is constant 12v power for station memory and operating power. Pin C of the 3 pin connector is acc 12v power. The radio gets power via the tape deck.
On the tape deck: Pin C of the 6 pin connector is acc 12v power for operation. Pin B is pass through acc 12v power and connects to pin C of the tuner. The connection between pin C and pin B is normally open so the tuner works. When you insert a cassette the connection is closed and the radio loses power. The lights on the radio still work because they get power from illumination. The volume, bass, fader work because those are just inline with the audio signal and nothing else. So the tuner is essentially turned off when you insert the tape.
With that knowledge, here's how you eliminate "ghost signal". De-pin the 3-pin connector to the radio and place a SPDT relay inline with pin C. Make sure you use 87a on the relay so the radio gets power when the relay is deactivated. Place a switch somewhere to activate the relay when you are ready to use the AUX input. To be really clever, you can use a 1/8" chassis mount jack that has a built in switch that is activated when someone inserts a cord. It will ground out and cause the relay to activate. You might even be able to install something like that on the face of the radio.
