Audiovalve CORDA EARTUBE-1 User Manual

EARTUBE

USER MANUAL

Dear music-lover,

The CORDA EARTUBE-1 is a small-power amplifier, specially designed to drive headphones. It offers
a sound quality and driving capabilities far beyond that of an ordinary headphone socket found on a
CD-player or amplifier and thus allows you to exploit the full sonic potential of your phones.

Due to the close contact to your ears, headphones provide an extreme channel separation whilst
listening to stereo recordings. Unlike loudspeakers, none of the sonic information in the left channel is
acoustically transferred to the right ear and vice versa. Although this adds to the extreme high level of
detail that can be achieved with headphones, it subconsciously also introduces mental stress. The
natural correlation of stereo sound interpreted by the brain is lost.

The CORDA EARTUBE-1 not only offers normal stereo reproduction of your music, but it also has a
facility to add some of the left channel information to that of the right channel and vice versa. Thus
mental stress is reduced and music can be enjoyed with more ease.

By design only tubes are found inside the signal path of the amp. Solid state electronics are only used
to create a stable voltage supply.

For safety and in order to obtain the best possible results with your new headphone preamplifier, we
ask you to read these instructions carefully. The EARTUBE-1 was developed by music-lovers for
music-lovers and we hope that it will serve you well for a long time.

Helmut Becker

Safety precautions

Children and minors are not to use the device and should be kept at a safe distance from the device
while it is running.

Do not run the device without the top cover in place. Voltages inside the amp can be lethal and
temperatures are high.

Please check that the mains voltage printed on the bottom panel of the amplifier corresponds with the
mains voltage in the country where you intend to use the amplifier.

Disconnect the powercord before any service to the amplifier.

In the unlikely event of a failure of the device repairs may be performed by authorized technicians
only.

Use ORIGINAL spare parts only!

Please take note of the fact that we decline product liability for damages caused by our devices, parts
and components as a result of:

Unprofessional and/or faulty and/or incorrect repairs that have been performed in other than
the approved repair facilities.

Usage of other than ORIGINAL and approved spare parts.

All devices must be operated under moderate climatological circumstances, comparable to those
under which human beings usually live. When the surrounding temperature is too high, the device will
heat up beyond its optimal parameters. This can damage the amplifier.

Proper ventilation is needed, and the amplifier should not be covered in. Allow approximately 3 cm of
air sidewise and approximately 4 cm above the amplifier to cool the amplifier.

Once the amplifier has arrived at its desired destination, make sure the amplifier has ample time to
adjust to the climate at its new location. It is likely that the changes in temperature and humidity
between the last location and the new one, has caused condensation to build up somewhere in the
amplifier. This can damage the device. Please allow the amplifier at least two hours to acclimatise.

The amplifier comes fully assembled, ready to go.

The decive MUST be switched OFF while connecting it to other components.

A softstart prevents high initial currents through the cold, low impedance, heating element. This
prevents the element to break at its most narrow spot.

Connections

At the rear side of the CORDA EARTUBE-1 two pairs of inputs allow you to connect two different
audio sources that have typical output voltages above 0.1 Volts (CD-player, cassette-player, tuner,
minidisc-player, ...). The source you want to listen to can be selected by the switch at the left front side
of the amp.

If your audio system already contains a central preamplifier or integrated amplifier you may prefer to
connect the EARTUBE-1 to the tape-out of your central amplifier. The source now can be selected by
the Rec-switch of this central amp.

Your headphone should be connected to one of the headphone-sockets on the front side of the
EARTUBE-1. You can also use the sockets to connect two headphones simultaneously.

The sockets are intended for 6.35 mm stereo jacks. If your headphone only has a 3.5 mm jack, then
use an adapter that can be obtained in most electronics or audio shops.