Soundstream Technologies 644s Stereo Amplifier User Manual


 
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INSTALLATION STEP 5
L
LEVEL SETTING
The input levels are adjusted by means of the individual channel input level
controls located on the front of the amplifier. This is a unique dual-stage circuit
that adjusts both level and gain. This topology maintains better Signal-to-Noise
ratios even when using sources with minimal output.
In the ideal situation, all components in the audio system reach maximum
undistorted output at the same time. The reason is because an amplifier will
only make what comes into it bigger. So, if you send it a distorted signal from
the head unit, the amplifier is going to amplify distorted information. The same
thing holds true if an outboard processor or crossover begins to distort before
you have maximum output from the amplifier. By setting all components to
reach clipping at the same time, you can maximize the output of your system.
For the REFERENCE amplifiers, follow the steps below for the quickest, easiest
means of setting the levels.
Level Setting the Reference414s
1.
Turn
the amp’s input levels to minimum position (fully counter-clockwise).
2. Set source unit volume to approximately
3/4
of full volume.
3. While playing dynamic source material, slowly increase the amplifier’s
input level until a near maximum undistorted level is heard in the system.
4. Continue to adjust the gains independently in order to adjust the desired
balance between satellite speakers and subwoofers.
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NOTE: Even though the
S/N
ratio
with
low output sources is better
with
the
REFERENCE414s
amplifier than others, your best
combination of output level and
Signal-to-Noise
ratio
will be
achieved when the input levels
are
set between 1.0 V and 5.0 V.
1.
2.
3.
4.
5.
6.
Level Setting the Reference644s
Turn the amp’s input levels to minimum position (fully counter-dockwise).
If any channel is in low pass mode, set the subwoofer level pot to the 0
dB
position (12 o’clock).
Begin with the input level switches in the 0.5 5.0 Volt position.
Set source unit volume to approximately
3/4
of full volume.
While playing dynamic source material, slowly increase the amplifier’s
input levels until a near maximum undistorted level is heard in the system.
If you can’t get enough gain out of the amplifier, set the input level switch
to the 0.2 2.0 Volt position, and repeat steps 3 and 4.
If any channel is in low
pas
mode, you may have to adjust the subwoofer
level control pot to achieve a good balance between satellites and
subwoofers.
If your preamplifier / source unit has an extremely high output level,
be
sure to
pay attention to the clipping indicators located on the top of the amplifier. These
indicators will notify you if you are clipping the
PREAMPLlFlER
stage of the
amplifier. If the amplifier’s output is distorted and the clipping lights are
not
blinking, you are most likely clipping the OUTPUTS of the amplifier, or driving
the speaker to distortion.
There is an additional control for subwoofer level adjustment on the
Reference644s.
The purpose of this control is to provide additional range of
adjustment for the subwoofer signal in relation to the high pass signal. This
control adjusts the level of any channels or RCA signal outputs in low pass
mode.
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