PhonoPreAmp iVinyl (English)
9
distorted. The reason: as the deflection of the needle is limited to specific range, high fre-
quencies (= low amplitude) are amplified and low frequencies (= high amplitude) are weak-
ened on the record. The signal from the pickup must therefore be processed (filtered) before it
can be used.
The Recording Industry Association of America (RIAA) has defined a standard for the changes
to the frequency ranges to ensure that all records can be played using the same filtering. The
quality of the equalization process is thus an important factor in the overall quality of a phono
preamplifier.
Shielding
Due to the relatively low output levels that even moving-magnet systems achieve (MM approx.
2-5 mV, MC approx. 0.1-0.4 mV), a certain amount of protection has to be provided against
external sources of noise. For example, using an overly simple power supply design can result
in unpleasant AC hum.
Unfortunately, the mounting number of electronic devices in an average household means an
increasing amount of electromagnetic interference. While these waves are very weak, they can
still interfere with the signal from the pickup, which is also very weak, as mentioned above.
This problem can be dealt with by carefully shielding the amplifier, as is the case with the
PhonoPreAmp iVinyl
.
The ground wire of your turntable, if present, also fits in with this topic. This wire establishes
an electrical connection between the turntable and the shielding to help prevent AC hum.
We've got this one covered, too. The
PhonoPreAmp iVinyl
is equipped with an extra ground
connection, which passes completely through the device, to the USB port, and then into the
computer. This guarantees maximum shielding.
Recording
Included with the
PhonoPreAmp iVinyl
is
Sound Rescue
TerraTec Edition 2.1
, a professional
software application for restoring your audio recordings. For more information, refer to the
Recording
chapter later in this manual. Start
Sound Rescue
TerraTec Edition 2.1
as described
in the manual and begin recording.
To achieve optimal level control when recording, it is important to adjust the input level of the
PhonoPreAmp iVinyl
correctly. Play the record you want to record and watch the peak LED on
the
PhonoPreAmp iVinyl
while doing so. Whenever possible, set the input level to MAX. If the
blue LED lights up, it means the input signal is being amplified to strongly. In this case, set the
input level back to MIN. With this setting, the LED should not indicate any more overamplifica-
tion (peaks). Unlike recordings that you may have made in the past with a tape deck, digital
recordings must
never
exceed the maximum level. In the analog world, this might have passed
for a desirable “tape saturation” effect, but with digital recording technology it leads to clearly
audible distortion which is virtually impossible to “repair”.
