Dave Hill Designs EUROPA I, Руководство пользователя, Страница: 4 / 13

INTRODUCTION
Europa 1 is a preamplifier that is constructed with 91 transistors in it’s main audio path and it is of
discrete Class A topology. The preamplifier controls are either traditional pre-amplifier type controls
or color controls. It is also necessary to understand that distortion may not sound like what one
normally thinks distortion is. Distortions can be very pleasing colors - sounds.
POWER UP Allow a 20 minute warm up period for optimum operation.
The gain display shows the firmware version on power up, this is the left most digit of the gain display
GAIN The gain control circuit uses some of the latest technology that allows digital gain control over
analog circuits. The preamplifier circuit with it’s gain control elements has 1 db gain steps that range
of 0 db of gain to 66 db of gain. The maximum signal level is +24dbu. Balanced in, balanced or
unbalanced out. The 0 db gain setting allows for post processing during mixing, and eliminates the
need for a pad switch. Gain is displayed on a 2 digit display.
Other standard preamplifier type control functions are also available. They are, phase flip and 48 volt
phantom power.
INPUT IMPEDANCE The input impedance of the mic preamplifier has 3 choices.
The HI-z selection is in the range of 200K ohm and will provide very little loading of the source. The
second position has an impedance of approximately 2.2K ohms. With the third position having an
input impedance of 300 ohms for color choices.
SPEED Speed is the first control in the color set. All color controls are series connected. They
affect each other. The speed control changes the slew rate of the preamplifier. This is the same as
rate of change. The result of this is that low level signals are unaffected, but a large signals that
changes quickly will be slowed down. See wave form photos.
EVEN HARMONICS The even harmonic control changes the amount of even harmonic content.
This is a color that can thicken a sound and is very difficult to describe. This is mostly second
harmonic.
ODD HARMONICS The odd harmonic control changes the amount of odd harmonics that are added
to the audio path. Odd harmonics can make a sound brighter and the way this control works it can
also add detail and a compression effect. The compression happens because of amplifier overload.
LOW CUT The hi-pass filter is a third order 18 db pre octave filter of a type that has good time
domain response. The filter has 8 frequencies 148 Hz, 130 Hz, 117 Hz, 100 Hz, 81 Hz, 63 Hz, 48
Hz, 33 Hz, and off.
INSTRUMENT INPUT The instrument input has 1.2 Meg ohm impedance and has a gain range of 0
db to 30 db
METER The meter is calibrated so that 0VU on the meter is +4 dbu, the top of the meter shows +20
db above +4. The maximum level is +24 dbu.