HEVOS 400C User manual

HEVOS
Owner’s manual
400C
amplifier

Safety instructions
1. This amplifier is supplied with ~230V or ~115V. Connect the
amplifier exclusively to a power point with earth connection.
Never open the amplifier. Repairs are exclusively done by Hevos
and by companies that have been authorized by Hevos. Otherwise
the warranty will become void.
2. The amplifier should not be used outdoors. Avoid exceptionally
warm places, places that are dusty or dirty and places of high
humidity .
3. If the power cable is damaged, the amplifier has been dropped or
the amplifier is not working correctly immediately switch off the
amplifier and disconnect it from the power point. The amplifier
should be repaired by an authorized company only.
4. Never pull out the plug by the cable.
5. For cleaning, only use a dry soft cloth. Never use any water or
chemicals.
6. In case of illicit or wrong use, wrong connection, wrong control or
repair by a non-authorized company or person the warranty will
become void as well.
7. Whenever you want to dispose of the amplifier, hand it in at your
local recycling company.
8. Never connect the Line Out to a mixing desk with Phantom Power
switched on! This can cause amplifier malfunction or even
damage.

Introduction
The 400C is a transistor amplifier with a continues power of 400 Watts.
The 2 inputs have separate gain controls. The led above input 1 is a clip
indicator which turns from green into red as soon as the input signal is
too high. If so, one should reduce the input signal by lowering the
volume of the instrument or the input gain at the amplifier.
Input 1 has a –6dB switch to reduce sensibility if necessary. This could
be the case by using an active bass guitar or double bass with separate
pre-amp. If the clip indicator turns into red often, one should put the
switch to –6 dB. The –6 dB switch is also useful to connect both an
active and passive bass at the same time. If both basses have a similar
output, the switch should be set to 0 dB.
Input 1 is provided with a phase turn switch, which can be useful
connecting a double bass with two different pick ups. By means of the
switch one puts one pick up out of phase, resulting in a different sound.
The pre amp is also equipped with a Mute Out to tune the instrument
soundlessly. By means of the Mute Out switch one can activate the
Mute Out. The internal signal is then interrupted and will be available
at the Mute Out to be sent to a tuning gear.

The tone control unit is a 4-band type and is very easy to use. The
frequencies are 80, 250, 800 and 2500 Hz , +/- 12 dB. The amplifier has
been built in such a way that in normal acoustic circumstances there
will be no need to use the tone control.
At the back are a Loudspeaker output, a Headphone output and a
symmetrical Line Out with pre/post switch. The pre/post switch
controls the point in the amplifier circuit where the line out signal
comes from. Pre comes just behind the input and is not controlled by
gain nor tone control, post comes behind the tone control. Never
connect the Line Out to a mixing desk with Phantom Power switched
on! This can cause amplifier malfunction or even damage.
The loudspeaker output has a minimal load of 4 Ohms. Built in a combo
one can connect an extra loudspeaker cabinet of 8 Ohms. Together
with the internal loudspeaker of 8 Ohms one has a total load of 4
Ohms, forcing the power amp to give its maximal power of 400 Watts.
The headphone can be controlled by means of the gain and master
knob.
The 400C has a built-in delay and is protected against short circuit and
clipping. The 400C is powered by a class-D power amplifier with UcD
technics, resulting in an extremely stable amplifier which works
noiselessly. The high efficiency of the class-D power amp makes any
active cooling redundant.

Installation directions for use
1. Connect the amplifier exclusively to a power-point with earth
pin.
2. When you connect or disconnect your bass, take care the Gain
knob is put to 0 or use the Mute switch to avoid switch clicks.
3. In order to set a distortion-free amplification it is advised to open
the Master knob ¾ to full. After that the volume is controlled by
using the Gain knob.
4. Under normal acoustical circumstances there is no need to use
the tone controls. However, if one should use the tone controls, it
is advised to do so carefully. Each tone control goes up to +12/-12
dB. The sensitivity increases while turning the knob clockwise and
anticlockwise.
5. The minimal impedance of an extra loudspeaker cabinet (400C in
combo) is 8 Ohms.
6. Only use a loudspeaker cable of excellent quality.

Control panel
1. –6dB switch: reduces the sensibility of Input 1
2. Phase turn switch: puts one pick up out of phase when using 2 pick
ups (double bass).
3. Input 1
4. Gain Input 1: controls the signal amplitude towards the pre amp.
5. Input
6. Gain Input 2: controls the signal amplitude towards the pre amp.
7. Mute switch: activates the Mute-Out at the back.
8. Low: tone control 80 Hz, ± 12 dB, Q = 0,5
9. Low-Mid: tone control 250 Hz, ± 12 dB, Q = 0,5
10. Mid-High: tone control 800 Hz, ± 12 dB, Q = 0,5
11. High: tone control >2500 Hz, ± 12 dB, Q = 0,5
12. Master: controls the signal amplitude to the power amp.
13. On/Clip led: green at power-on. Red when the input signal is too
high.
14. Led Mute-Out

1. Loudspeaker output: to connect loudspeaker cabinets with a
minimal total impedance of 4 Ohms, or built in a combo, to connect an
extra cabinet of 8 Ohms.
2. Line-out: symmetrical XLR-output to PA/mixing console.
3. Pre/post switch: taps the line out signal from pre-Gain or from post-
Tone Control position.
4. Headphone output
5. Mute-Out: connector for tuning gear.
6. Ground Lift switch: cuts the earth between amplifier and PA/mixing
console if necessary.
The power connector has a built-in fuse ( 4A/6.3A slow) and spare fuse.
The fuse box can be opened with a screw driver. The appropriate
voltage of your country is set as a default. Changing the voltage can
damage the amplifier irreparably.
Technical features
Type: transistor/class-D MosFet bass amplifier
Power: 400 Watts into 4 Ohms, 1 kHz, < 0,01% distortion
Damping: > 2000 at 100 Hz in 4 Ohms
Input: 2x, both to be used independently.
Tone control: active, 4 band: 80, 250, 800, and >2500 Hz +/-12 dB
Protection: short circuit, DC current on output, mismatch and open
end; clip indicator; delayed power switch.
Divers: Mute Out; symmetric Line Out with pre/post switch,
Headphone Out, Ground Lift.
Output: Loudspeaker, Line Out, Mute Out, Headphone

Product warranty and service
This product is guaranteed against defects of used materials and
operation from the moment of purchase during a period of two years. If
during this warranty period this product does not function properly,
Hevos will fit the product to the use it is intended for without passing on
the costs of labour and materials to the purchaser under the following
strict conditions:
Conditions:
1. The obligation of Hevos is restricted to the repair or replacement of
defects. Hevos is at liberty to decide whether it should be repair or
replacement. Transport costs are at the purchaser’s expense. Hevos
cannot be held responsible for any kind of risk during transport (e.g.
loss, damage etc).
2. All repairs under warranty should be done by Hevos or a company
that has been authorized by Hevos. Repairs by non-authorized
companies are no part of this warranty. If the product is damaged
due to non-authorized repairs then this warranty will become void.
3. This warranty applies only for defects of used materials and
operation. The warranty does not apply for:
damage caused by lightning, induction, faulty power supplies,
faulty power cords, insufficient ventilation, flooding, fire, smoke,
peace disturbances hooliganism and war.
damage caused by accidents, negligence, modifications and
wrong use or wrong installation or wrong transport
products with illegible serial numbers or numbers that have
been tampered with
4. The warranty expires when the product is used in a wrong way, is
hired, lent or sold to third parties.
5. Specifications and information contained in this manual are
furnished for informational use only, and are subject to change at
any time without notice and should not be construed as a
commitment by Hevos. Hevos assumes no responsibility or liability
for any errors inaccuracies that may appear in this manual.
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