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Astrodyne Power Supply
Power Supply & Power Supply Upgrades
What is The HeadRoom Crossfeed?
The Desktop Power Supply (DPS) is available as an upgrade. All HeadRoom amps come
with a surprisingly good, but still inexpensive, power supply. Any audiophile will tell
you that the power supply is as, or almost as important as the audio electronics them-
selves. This is true, and the Desktop Supply will help you get every last drop of per-
formance out of the amp you buy. Maximum current output before a potential loss in
audio quality is 500 mA. For the best performance, we recommend one dedicated DPS
for each headphone amp.
Included with the Ultra Desktop Amp is the Astrodyne power supply, an upgraded sup-
ply to accommodate for the demanding Max-level electronics and DAC. We also rec-
ommend the Astrodyne as an excellent, budget-friendly power upgrade for the stan-
dard Desktop Amp. The Astrodyne is a switching-voltage supply, so it may be used
in any country. The Astrodyne provides clean, quiet, robust current on demand, and
shows nice performance gains over the linear regulated AC wallwarts included with
the Desktop Amp.
ground lift
switch
power entry
module
power outputs
Power Entry Module
The Power Entry Module is where the Power Supply plugs
into the wall. The power entry module can also be easily changed into other common
international voltages. The red window box on the power entry module indicates the
current voltage setting of your amplifier. You can easily switch the voltage between
115 VAC and 230 VAC by carefully opening the power receptacle window housing, then
simply slide out the receptacle and reinsert it facing the opposite way until the desired
voltage clearly shows through the power module window box.
Ground Lift
The Ground Lift seperates the audio signal ground from the power sup-
ply ground. Usually, you will want the Ground Lift Switch to be set to ‘normal’, but if
you hear a slight buzzing noise in your system, then turn it to ‘float’.
Power Outputs
There are 6 power outputs on the Desktop Power Supply, and is ap-
propriate for use with any of the HeadRoom Desktop or Micro Lines of amps and DACs.
Imagine you are listening to a pair of speakers. If you turn off the left speaker,
both ears hear the sound from the right speaker. But because the left ear is
slight farther away than the right ear, it hears the speaker’s sound slightly
after the right ear; about 300 microSeconds. This time difference is called the
“inter-aural time difference” and it is the main thing your brain listens for in
order to tell where to place sound left-to-right.
But in headphones if you turn off the left channel, only the right ear hears the
sound. In headphones, if there is any sound that is only in the left channel,
or only in the right channel, then only that ear hears the sound. This is not
natural, and you brain becomes fatigued trying to figure out where sound is
coming from when only one ear is hearing it. This tends to create an audio im-
age that is a blob on the left, blob on the right and a blob in the middle.
HeadRoom amplifiers cure the problem by allowing you to cross-feed a little
of the left and right channels across to each other through a short time delay
using the processor switch. The usefulness of the circuit varies depending
on what type of recording you are listening to; mono and binaural recordings
need no processor at all. Old studio recordings that have instruments panned
hard left or right, benefit greatly from the processor. Live and classical record-
ings miked from a distance benefit somewhat less, and can often be listened
to without the processor quite comfortably.
Plain
Headphones
With
HeadRoom
The crossfeed switch in
HeadRoom amplifiers al-
low you to cross-feed a
little of the left and right
channels across to eacho-
ther through a short time
delay.
Far ear
hears
slight delay.
Near ear
hears sound
first.
30 degrees
off axis
Desktop Power Supply
