Blaupunkt EMA 255 manual Plus / minus connection

EMA 255

Plus / minus connection

–We recommend a minimum cross section of 6 mm2.

–Route commercially available plus cables to the battery and connect via fuse holder.

–Use cable glands for holes with sharp edges.

–Securely fasten commercially available minus cables to a noise-free earth point (chassis screw, chassis metal) (not to the minus pole of the battery).

–Scrap the contact surfaces of the earth point until they are bright and grease with graphite grease.

Integrated fuses (Fuse)

The fuses integrated in the amplifier (Fuse) protect the power amplifier and the entire electrical system in case of an error. If a replacement fuse is used, never bridge fuses or replace them with a type with higher current.

Connection examples

Connection of the voltage supply	Fig. 2
Audio inputs	Fig. 3
Loudspeaker connections	Fig. 4/5/6

+12V

Remote connection of the amplifier with switchable +12 V voltage source.

This allows the amplifier to be switched on and off using the on/off-switch of the radio device.

Level control

The Level control is used to adjust the input sensitivity of the power amplifier to the output voltage of your car sound system preamplifier output.

The adjustment range is from 0.2 V to 10 V.

If a car sound system of a third party manufacturer is con- nected, the input sensitivity must be adjusted corresponding to the manufacturer data.

A few important explanations in this context:

By turning the control clockwise, the input sensitivity of the amplifier and, therefore, also the volume increases. However, this is not a volume control; no further amplifier output can be achieved in the end position, even if it may sound like that at the beginning. The system merely increases the volume faster if the volume control of the car sound system is turned up.

Loudspeaker connections

(If the amplifier is to be jumpered, continue with the section "Bridged loudspeaker connections" at this point).

As with every audio component, the correct polarisation of amplifier and loudspeakers is of essentially importance for a good bass response. For this reason, ensure that the positive

(+)connection of the amplifier is connected with the posi- tive connection (+) of the loudspeaker; the same applies to the negative (-) connections. In addition, the left amplifier channel must be connected with the left loudspeaker and the right amplifier channel with the right loudspeaker.

Bridged loudspeaker connections

The EMA amplifier can also be bridged for a mono configura- tion. This allows the amplifier to be used for one or several subwoofers or mid-range drivers. In this configuration, the amplifier combines the right and left channel to a single- channel output (mono output).

Note:

The amplifier can add the right and left signal information only if the right as well as the left RCA connection were carried out.

Caution:

In a bridge circuit, the amplifier load must be 4 ohm or higher. A lower load leads to an overheating or switch-off of the amplifier and can cause permanent damages.

Adjusting the type and range of the frequency crossovers

With the EMA 255, the type of frequency crossover (i.e. "Low Pass" or "Hi-Pass") and the desired entry frequency can be adjusted. For example, if a pair of subwoofers is to be con- nected, the low-pass settings shown are required (Fig. 3). The entry frequency is dependent upon the frequency range of the loudspeakers (see recommended frequency range of the loudspeakers).

High-Pass

At a setting of 80 Hz, the amplifier has a frequency range of 80 Hz to 30,000 Hz.

Low-pass frequency control

This control is active if the switch is in the position "Low-Pass", and allows for setting the desired entry frequency.

Example:

At a setting of 150 Hz, the amplifier has a frequency range of 10 Hz to 150 Hz.

Bass boost

The bass boost control is used to adjust the bass response of the amplifier.

The setting options are: 0 dB / +6 dB / +12 dB.

Power-on indicator (PWR / PRO)

Green LED:

Output stage on, regular operating status.

Red LED:

Output stage is electronically switched off due to an error.

Recycling and disposal

Please use the return and collection systems avail- able to dispose of the product.

Subject to changes

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