400C combo amplifier

400c in kast

Technical data:

Type: transistor class-D
Hxwxd: 8x23x20 cm
Power: 400 Watts/4 Ohms
Damping: >2000/1 kHz/4 Ohms
Inputs: 2x, separated
Tone control: 4 band active
Protection: short circuit,open output,DC-protection output, temperature protection, mismatch, clip, delayed switch on/off
Divers: mute-out,headphone output, -6dB switch, phase turn switch, symmetrical line-out with pre-post switch
Output: 1x Speakon
Weight: 1.8 kgs

400C intern

The 400C is an ultra compact amplifier of 23 x 20 x 8 cm,  with a total weight of  less than 2 kgs. Thanks to the application of the newest technics the 400C is completely quiet, even at full power. The class-D technics takes care of the absence of heat dissipation, resulting in a very compact design.

The 400C is an amplifier with a continues power of 400 Watts. The 2 inputs have separate Gain controls. This allows you to connect 2 basses at the same time, or in case of a double bass 2 pick ups.  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 best 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 of the amp 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.

The loudspeaker output has a minimal load of 4 Ohms , so it is possible to connect  an additional loudspeaker cabinet of 8 Ohms. The headphone can be controlled by means of the Gain and Master knob. The 400C has a built-in start 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 cooling redundant.