Autoset; Hi Z - RME Audio Micstasy User Manual

9.7 AutoSet

Some preamps include limiters in order to prevent clipping, especially of the A/D converter
stage. Such a circuitry is not feasible for the Micstasy, because it would spoil the mic preamp's
excellent technical data.
But as the Micstasy's gain is controlled completely digitally, the device can set it automatically,
thus providing perfect protection from overload with no degradation of the audio signal, which
does not have to pass any additional electronic circuits.
Since AutoSet operates as overload protection and not as 'compressor', there is no automatic
gain increase. AutoSet only reduces gain. In the Setup menu, the threshold level beyond which
the gain will be reduced can be adjusted in four steps (-1, -3, -6, -12 dBFS). Any change of gain
will be shown immediately on the GAIN displays. And with AutoSet activated, the gain can still
be changed manually. The currently highest possible value can not be exceeded, because
AutoSet will reduce the gain in real-time during the manual change.
In practice, there are two possible ways to work with AutoSet:
• Gain of all channels is set to a rather high value, e.g. 60 dB. Then a rehearsal with maximum
acoustic level is performed. Thereafter AutoSet is switched off.
• As above, with AutoSet permanently active.
There are good reasons for both of these alternatives. Thanks to the flexible threshold setting
and easy manual correction of set values, the Micstasy is fit for all applications.
The values set by AutoSet can easily be changed globally, or for individual or multiple channels,
without changing the gain relation between channels. Pressing the encoder knob will make all
gain displays flash. Turning the encoder left or right will decrease or increase the gain values by
any desired value (in dB).
AutoSet allows single or multiple channels to be linked with the channel to the left. More infor-
mation can be found in chapter 11.9, AutoSet Down-Link.
AutoSet reduces gain by about 20 dB in 10 ms. Under certain level states, this can lead to a
short clipping of the AD-converter. In practical tests, we found it hard to detect these clippings.
This is only possible with sustained signals including extreme level jumps, and is comparatively
harmless even in these cases. Additionally AutoSet does not cause any of the control noises
known from usual Limiters, SNR and THD stay completely unchanged. Just try it out - AutoSet
will convince you too!
Micstasy remembers all settings when it is switched off. The AutoSet state is also included
when storing to a preset. However AutoSet is always deactivated after the device is switched
on, to prevent accidental changes of previously determined gain values.
Note: AutoSet is the only function that can be globally activated via SET and a right turn of the
encoder knob.

9.8 HI Z

The front input INST/LINE has an input impedance of 5.6 kOhm. Connecting passive instru-
ments like bass and guitar, an activation of HI Z changes the input impedance to 470 kOhm,
providing perfect conditions for these types of signal sources.
User's Guide Micstasy © RME
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