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Why is a high damping factor essential ?
When actuated, electro-dynamic systems respond with a counterforce.
When the voice coil of a headphone has been displaced by the signal, an
(error) current will be induced when it swings back to its initial position.
This current must be suppressed as far as possible, which is effected
best if the amplifier's output impedance is the lowest possible. The
damping factor describes nothing but the ratio between output impedance
of an amplifier and a given load.
Since there is no known technical specifications, we define the load
(voice coil impedance) as 50 ohms. This results in an output impedance
of <0.12 ohms for the V100.
The power supply with its supersized toroidal transformer provides the
power stage with +/-30 volts. The preamp stage is supplied with
stab/-18 volts.
Why are high supply voltages essential ?
A headphone doesn't really require high power, but from the equation P =
U
2
/ R we can see that the square of the supply voltage determines the
power into a given load resistance. The higher the headphone's
impedance, the more voltage will be needed. But this deals with the
achievable loudness to a limited extent only: Technically spoken, music
lives on fast transients which put high demands on signal processing.
And thus a fast transient can easily push an average amplifier with +/-15
volts supply to its limits. Due to out high supply voltage you will benefit
from doubled output swing capability.
The headphone jacks are disconnected by relay during power-up /
power-down.
Why does a relay make sense when switching power ?
Amplifiers generate unwanted output signals when applying or removing
power, which can damage the connected headphones. The relay breaks
the connection between amplifier and headphone and thus protects the
latter until electrical conditions have stabilized.
