Neumann.Berlin U 67, Руководство по эксплуатации, Страница: 11 / 20

EN EN
11
9. Power Supply Unit
The NU 67 V power supply unit is also available
separately:
NU 67 V ...................gr .................. Cat.No. 008679
(included in the supply schedule)
This classical power supply unit contains a mains
transformer. It automatically switches between
the 100-120 V and 220-240 V ac mains voltage
ranges.
In the OFF position the NU 67 V draws no current.
Note:
the older power supply units NU 67 (u) and
NU 67 A only delivered a heater current of 220 mA
max. When using these supplies for U 67 from pro-
duction date 2018 onwards, the equivalent noise
level can rise relevantly, as the vacuum tube will
be underheated.
In the opposite case, the new NU 67 V is suitable
for powering all U 67 of any vintage
For further information please contact our service
at www.neumann.com.
Operation with Unbalanced Inputs
At the power supply unit, the audio signal is
available at a balanced, floating XLR 3 output.
The output is wired as per IEC 60268-12 and
IEC 61938:
Pin 1: 0 V/Masse
Pin 2: audio signal (+phase)
Pin 3: audio signal (–phase)
So pin 2 is the “hot phase”, pin 3 must be con-
nected to ground when used with unbalanced
inputs (see figure 1).