396 isolate audio out

[pyeman99]

This may have been covered.
Someone please confirm that it is required to isolate the headphone socket before connecting it to a recorder or PC.
ie DC on the phone socket...use a RS transformer ?
Thanks Keith.

 

[pro92b]

If the device has a stereo input plug and high input impedance it is not absolutely necessary to use transformer isolation. I still recommend it and use it myself but you could run without it. The attachment gives more details.

 

[pyeman99]

If the device has a stereo input plug and high input impedance it is not absolutely necessary to use transformer isolation. I still recommend it and use it myself but you could run without it. The attachment gives more details.

Magic very many Thanks Keith

 

[Scanark]

What about connecting the 396 to an auto speaker system through the external input jack via cable from the 396? Will this possibly damage the unit?

 

[N1508J]

Possible no no!

What about connecting the 396 to an auto speaker system through the external input jack via cable from the 396? Will this possibly damage the unit?

Depends what you mean by an "auto speaker system". As posted earlier, you wana keep any external current or grounds from the headphone jack. Unless you know your speaker system external input is free of a ground or energy created within it, I would use the 1:1 isolation transformer suggested.

 

[slicerwizard]

What about connecting the 396 to an auto speaker system through the external input jack via cable from the 396? Will this possibly damage the unit?

Depends on whether the 396 has any other connections to the vehicle. Is it using a DC power cable? A magmount antenna? If not, no problems. If it is, you need a DC blocking capacitor in your audio cable circuit.

 

[slicerwizard]

The attachment gives more details.

Just nitpicking here - the schematic doesn't show the RC feedback circuit from pin 7 to pin 1 or the highpass RC components between pins 5 and 7.