Analog Inputs / Outputs; Mic / Line In Rear; Instrument / Line In Front - RME Audio Micstasy User Manual

13. Analog Inputs / Outputs

13.1 Mic / Line In Rear

The Micstasy has 8 balanced full range XLR inputs on the back panel. The electronic input
stage is built in a servo balanced design which handles unbalanced and balanced signals cor-
rectly, automatically adjusting the level reference.
When using unbalanced cables be sure to connect pin 3 (-) to 1 (ground). Otherwise noise
may occur, caused by the unconnected negative input of the balanced input.
The pin assignment follows international standards. With XLR, pin 2 is + or hot, pin 3 is – or
cold, pin 1 is ground. Pin 1 is connected to the chassis directly at the socket (AES48).
The rear inputs of the Micstasy offer an adjustable amplification from -9 dB up to +76.5 dB. This
equals a sensitivity of +30 dBu down to –56.5 dBu, referenced to full scale of the AD-converter.
Changing the gain is usually done click-free, as the gain change is performed during the zero
crossing of the audio signal, if possible.
The soft switching, hi-current phantom power (48 Volt) provides a professional handling of con-
denser microphones. The usage of a hi-end integrated circuit (PGA 2500) plus a fully symmetri-
cal signal path guarantees outstanding sound quality, stunning low THD, and maximum Signal
to Noise ratio in any gain setting.
Due to the Micstasy's flexibility, its signal to noise ratio is not easy to determine. The EIN value
is constant across a very wide amplification range, typically 127 dBu at 150 Ohm input imped-
ance. Even at a gain setting of 30, which corresponds to 0 dBFS at only -9 dBu, the EIN still
reaches 122 dBu.
The Micstasy's 'overall' amplification from analog input to analog output depends on the analog
output reference setting. The EIN is not affected by this setting, since the S/N ratio scales 1:1
with the output amplification.
The Micstasy also delivers excellent performance as a converter for line signals. At a reference
level of +21 dBu for 0 dBFS (GAIN 00), S/N is 113 dBu unweighted (116 dBA). At +13 dBu for
digital full scale, it is 110 dBu unweighted (113 dBA). Due to a very special circuitry the signal to
noise ratio is completely independent from the source impedance. The front line input reaches
the exact same values as the rear input, from +21 dBu down to 0 dBu (GAIN 21.5).

13.2 Instrument / Line In Front

Line
The Micstasy's front has 8 balanced 1/4" TRS inputs. The electronic input stage is built in a
servo balanced design which handles unbalanced (mono jacks) and balanced (stereo jacks)
correctly, automatically adjusting the level reference.
When using unbalanced cables with TRS jacks: be sure to connect the 'ring' contact of the
TRS jack to ground. Otherwise noise may occur, caused by the unconnected negative input
of the balanced input
30
User's Guide Micstasy © RME