6.3. Channel indicators
Besides the A / B output assign indicators (see section 5.1.), the SAM614T has two useful
indicators on each of its channels.
The SP Signal Presence indicator (5) shows that signal is effectively present on the channel
input.
The CLIP indicator (6) warns that the channel is almost saturated. As a rule of thumb this
indicator should never stay lit permanently.
6.4. Equalization
Tone controls (9-11-13) provide a gain/attenuation of ±15dB for each of the three bands, which are
centered at 100Hz, 2kHz and 10kHz. Because of the intended applications of this unit, it has a tone control
system that needs a screwdriver to be used in order to perform the adjust, thus avoiding any error during
the normal use procedure.
6.5. Level indicators
These indicators (15) monitorize the signal level present on each output bus, before the final
volume control.
6.6. Audio monitoring
The signal present on the output buses A or B can be monitored through the PHONES output
(18). The pushbutton (16) selects the desired bus.
6.7. Ground loops, background noise
You should always make sure that the signal sources coming to the unit, as well as all devices
connected to its outputs, do not have their grounds interconnected, that is; ground must never come from
two different devices. Should this ever happen, noises could occur and seriously interfere the sound quality.
Cable shielding, when connected to the chassis, must never be interconnected, so as to avoid
ground loops.
The SAM614T mixer has been designed for the lowest possible background noise. Independently
from the electronic design itself, background noise level will directly depend on the right installation and use
of the mixing unit.
I. e.: setting a channel VOL to "2" and the output to "10" is not the same as the other way round.
In the first case, the signal coming to the mixing amplifier - which has got its own noise - is low, and so is
the signal-to-noise ratio (low signal). When the output amplifier boosts the whole signal we will get a very
high background noise. In the second case - with the channel fader at maximum - the mixing level is
high, and so is the signal-to-noise ratio. When the signal reaches the VOL OUTPUT and is boosted, it
will keep a much better signal-to-noise ratio than in the preceding case.
6.8. Cleaning
The front panel should not be cleaned with dissolvent or abrasive substances because silk-
printing could be damaged. To clean it, use a soft cloth slightly wet with water and neutral liquid soap;
dry it with a clean cloth. Be careful that water never gets into the unit through the holes of the front panel.
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