Seeburg HDLM 8 Operation Manual - 2. Connections
2. Connections
2.1. Power Supply
The HDLM 8 has a built-in universal power supply, which will work at all voltages worldwide between
90 and 240 volt and a frequency of 50 to 60 hertz.
Thanks to the Neutrik PowerCon, the power cord is mechanically safe connected to the HDLM 8.
The PowerCon connector must not be engaged or disengaged under live. To
power off the HDLM 8, one should unplug the socket of the outlet. Alternatively,
one might use an outlet strip with switch.
2.2. Analog Inputs and Outputs
The inputs and outputs, utilizing Neutrik XLR receptacles, meet the standard AES14-1992. The maxi-
mum RMS voltage is 20dBu.
The input section is built around an advanced circuit, which behaves similar to a transformer: the
common mode impedance is sigificantly higher than in conventional electronic inputs. This comes to
substantially better immunity against hum and high frequency noise, which result usually by filthy con-
tacts, thus having a mismatched input impedance.
The output impedance of both pin 2 (hot) and pin 3 (cold) are highly balanced. Thus, interferences may
be filtered out very efficiently in the next device.
Metal film resistors and high-grade operational amplifiers deliver outmost noise-free and distortion-less
audio signal.
A special circuit at the analog outputs prevents loud clunk noise if the power supply is interrupted.
2.3. AES/EBU Digital Inputs
The XLR inputs C and D can be individually switched to digital-in. These comply with the AES3
standard and are transformer-isolated. The audio signal will be converted to the internal sampling
frequency by an Asynchronous Sample Rate Converter, which is implemented in the FPGA. Thus, jitter
will be filtered out effectively. Latency is only 48 samples. Sampling frequencies between 32 and 96kHz
are supported. If both digital inputs are used, they must come with the same word clock, preferably
from the same source.
2.4. Optional Interfaces
2.4.1. ADAT/SPDIF Optical Interface
The HDLM 8 can be expanded with an ADAT interface to eight additional inputs. After that, the
HDLM 8 becomes an excellent output converter (D/A) and equalizer for digital mixing desks.
2.4.2. Gigabit AVB-Interface (Audio Video Broadcasting)
The HDLM 8 can be equipped with a 1000MBit AVB-aware ethernet interface. For further informations,
please ask SEEBURG directly.
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