Kurzweil K2000 - Power Problems and Solutions; Voltage Fluctuations and Soft Resets; Addressing Power Issues

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MAINTAIN.PUB 11/04/92
SECTION 4
4.5.4
4.5.5
4.5.6
4.6
4.6.1
4.6.2
Increasing the level too much can cause clipping distortion when
multiple notes are struck loudly. For dense sequences all
played through the same outputs, you will probably only be able
to increase the volume by 6dB or so without risk of distortion.
For monophonic instruments (lead guitar) or single instrument
tracks (such as drums), a substantially greater boost is
generally possible.
For the absolute maximum signal quality, the individual outputs
should be used. These are connected almost directly to the 18-
bit digital-to-analog converters with a minimum of noise-
inducing processing circuitry. A total dynamic range of over
100dB is available at these outputs. The MIX outputs are
naturally somewhat noisier because they represent the noise of
the individual outputs all mixed together, and the signal must
travel through more circuitry to reach them .
Programs which are routed through the K2000's global effects
processor (Output Group A) will also be slightly noisier than
programs routed to Output Group B. As with an external effects
unit, maximizing the input signal level (using the methods
described above) will improve the signal-to-noise ratio of the
effects processor. When in Effects mode, you will see an
internal Wet/Dry mix parameter; in the Effects Editor you will
find numerous parameters for setting the level of the various
effects. Your best signal-to-noise ratio will be achieved by
setting the effects level parameters to maximum and adjusting
the Wet/Dry Mix parameter to set the overall effects mix. If
you are only using the effects unit for EQ functions, one of the
EQ or Tone Control functions accessible through the program
Editor will produce quieter results then the global effects
processor's EQ functions (Parametric EQ, Para Bass, Para Mid, or
Para Treble, for example).
GROUND HUM
A common problem with all electronic musical gear is the hum
that can occur in connection cables due to AC ground loops.
Although "3-prong to 2-prong" AC adapters are frequently used
break ground loops, they also break the safety ground that
protects you from electric shock. Using these adapters is
dangerous and SHOULD NOT be done! Furthermore, although using
these adapters may reduce low-frequency hum, high-frequency line
noise (such as motor switching noise) is likely to get worse in
this case, since the K2000's AC noise filter will have no outlet
for the noise it filters if you disable the ground.
To reduce ground hum, you can increase your output signal levels
as described earlier in this section. Other safe procedures
include plugging your mixing board and amplifier into the same
outlet as your K2000, and making sure that all your gear is
properly grounded. If your're using an external SCSI device,
plug it into the same outlet as well. AC isolation transformers
are extremely effective at eliminating ground loops, and are
recommended for critical installations. A 75 watt transformer
is sufficient for the K2000.
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