Yamaha NU1 Owner's Manual page 28

Connections
 Minimizing noise of the input sound via Noise Gate
By default, this instrument cuts unwanted noise from the input sound. However,
this may result in wanted sounds also being cut, such as the soft decay sound of
the piano. To avoid this, set the Noise Gate to off via the following operation.
While holding down [FUNCTION], press the C#6 key repeatedly to toggle Noise
Gate on and off as needed.
r AUX OUT [L/L+R] [R] jacks
These jacks let you connect the instrument to external powered speaker systems,
for playing in larger venues at higher volumes.
Instrument
AUX OUT
Phone plug
(standard)
CAUTION
When the AUX OUT jacks are connected to an external device, first turn on the power to
the instrument, then to the external device. Reverse this order when you turn the power
off. Also, before turning the power on or off to all components, set all volume levels to
minimum (0).
NOTICE
When the AUX OUT jacks are connected to an external device, never connect the [AUX
IN] jacks to the output jacks of the external device. Doing so could result in feedback
(oscillation) that may damage both the devices.
t [USB TO DEVICE] terminal
This terminal allows connection to USB flash memory. Refer to "Connecting
USB flash memory" on page 23 for more information.
28 NU1
Owner's Manual
C#6
Powered speaker
Audio cable
AUX IN
Phone plug
(standard)
Default setting: ON
NOTE
Use audio cables and adaptor plugs with no
resistance.
NOTE
Use only the AUX OUT [L/L+R] jacks for
connection with a mono device.