Nibiru   MC RIAA phono preamplifier

Nibiru is a discrete design solid state current domain MC RIAA phono preamplifier operated by a pair of Pb gel batteries. Integrated intelligent battery charger is completely automatic so no user care is necessary. Nibiru has to be connected to mains in order to function even if totally off-line during playing music. For this feature there is a signal present detector that disconnects batteries from charger.
About one minute from the last music signal the batteries are automaticaly connected to the charger so the charging or trickle can take place. There are three LED indicators. The lower is mains and charging indicator, the middle is showing signal presence and the upper battery fault.

The total lack of switches or other user dependence is purposely done for two main reasons. First there is no need to alter cartridge to preamp interface since it is a pure current domain connection and as such not dummy loading dependent and second reason is that a listener must forget the equipment and enjoy listening to music.

It is necessary to accentuate that loading resistor used by a typical voltage design steals useful cartridge signal by shorting it to ground through it. Why throw away about 20% of the already tiny signal? Sure it is necessary to do so when using conventional voltage amplification but here this is not needed since current sink interface is the most optimal active load for any low impedance cartridge.

Behind the curtain   Nibiru phono preamplifier additional technical information

Features:

- transimpedance current domain principle of operation
- fully discrete signal path design
- class A output stage
- no series capacitors in signal chain
- only two caps per channel, both parallel to signal path, used for RIAA eq.
- no negative feedback in audio path
- totally automatic, carefree off-line battery charging
- user friendly, no manual status switching needed
- recommended continuous connection to mains

SPECIFICATIONS

INPUT: current sink
INPUT IMPEDANCE: 3 ohms
MIN. INPUT LEVEL: it can handle the lowest output cartridge in existence
MAX. GAIN: 70dB, cartridge dependent
FREQUENCY RESPONSE: 0/-1dB, 10Hz-100.000Hz
OUTPUT: pure class A, 100 ohm output impedance
OUTPUT LOAD: 600 Ohms or greater
MAX. OUTPUT LEVEL: +20dBm/600 Ohms (7.8V rms)
I-OUT: current domain output intended for connection with our Tiamat amplifier
MAX. NOISE & HUM: -85dBm, A weighted
SIGNAL/NOISE RATIO: 105dB
POWER REQUIREMENT: 200-240V (115V USA), 50/60Hz, 20W
BATTERY: min. 12 hours of continious play, Sonnenschein Dryfit A512/2.0S or Panasonic LC-122R2P/12V/2.2Ah used, other equivalents not recommended by technical or sonic reasons or both
MAX. DIMENSIONS: 295mm (W), 232mm (D), 113mm (H)
WEIGTH: 5.6 kg