About Balanced Headphone Amps - Violectric HPA V280 User Manual

Please note:
The RIGHT phone jack is connected to the in-phase stereo signal,
0
whereas the left phone jack is connected to the 180 phase shifted
signal. On power-up and power-down, the outputs are cut from the
amplifier circuitry by relay.
HINTS FOR THE BALANCED OPERATION
OF HEADPHONES
As there is no common standard about how to make the connectors of
balanced headphones and headphone amplifiers, we decided to equip
our unit(s) with 4-pin XLR connectors. In contrary to most XLR
standards the female socket is situated on the amp.
If you are not familiar in altering your headphones with matching
connectors we offer this work as a service. Please ask !!
ATTENTION:
Your headphone is double as loud as normal in balanced mode !!!
About Balanced Headphone Amplifiers
Different kinds of balanced applications and their advantages
The balanced signal line ...
... is used to maximize the noise and hum immunity of the signal line.
Who ever made a military service perhaps knows about the "field telephone"
which is a very simple thing without any electronics inside and without a power
supply. It is hooked to another field telephone with a simple twisted cable. This
cable can be as long as some kilometers and communication is still possible.
This is caused by the advantages of the twisted cable, the balanced line.
An easy and reliable approach to a balanced line is the use of transformers on
both ends.
This can be done even without the need of power.
Unfortunately those are expensive and suffer from unlinearities.
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