RuarkAudio R3 Mode D'emploi page 25

Line in and optical
You can listen to audio from an external analogue audio
source by connecting it to Line in or a digital source by
connecting it to Optical.
Input level adjustment
For best audio performance, we recommend you balance
the volume level of an external device (eg portable music
player or turntable) so its volume is about the same as
inbuilt sources like CD or USB.
If the volume is lower, increase the input level.
If the volume is higher or distorts, decrease the input
level.
You can adjust the input level by selecting MENU > Input
level and choose your desired level.
If your external audio source has a volume control you
may also need to adjust that.
Line in input levels
- 3dB (devices with high output level)
+ 0dB (devices with standard 2.1Vrms line level output)
+ 6dB (default)
+ 12dB (eg smartphones with high headphone output)
+ 18dB (eg smartphones with normal headphone output)
For best audio performance, we recommend you balance
the volume level of external devices by adjusting input
levels.