Rowland
Research is pleaesd to introduce a preamplifier which combines technical
innovation with unmatched beauty and ergonomics. Advances in field effect
transistor technology and research into low-level signal recognition and
resolution have positioned the Coherence One preamplifier as a standard by
which other units will be compared.
The
Coherence One is powered by a companion power supply which eliminates the
possibility of hum field contamination
in the low level circuitry. In addition, extra care was spent on overall
power supply design due to the understanding that an audio amplifier is simply
a modulated power supply.
Features
No negative
feedback in all circuit location
Direct
coupled design from input to output
Accepts both
moving coil or moving magnet cartridge inputs
Optional
strain-gauge cartridge inputs available
Passive RIAA
Equalization
All signal
switching accomplished with mil, spec, hermetically sealed, gold contact
relays.
Continuously
adjustable loading for moving coil cartridges
All FET in
voltage amplification stages
Precision
stepped attenuator for volume control
Muted
outputs during power outages.
An
amplification system must recognize and respond to all information presented to
it. The composite of this information, with all its subtleties and nuances, can
be defined as Musical Truth. Once recognized, this truth must be absolutely
maintained during the amplification process.
Recognition
of Musical Truth has been a shortcoming of most, if not all, amplification
systems. While few designers recognize and rigorously pursue the ideal, even
fewer approach the realization. Amplifying incompleteness will always be
unsatisfying to the music lover.
Maintenance
of Musical Truth during the amplification process has often led to novel and
ingenious design methods that produce spectacular specifications yet miss the
ideal altogether. Although technical measurements have their place, the
experienced ear must be the final arbiter of Musical truth
Rowland
Research has made a commitment to the ideal. This dedication is combined with
an intimate knowledge of electronic principles and components and a thorough
understanding of past and present techniques and accomplishments.
Specifications
Phono
Section
RIAA
Deviation: 20 Hz - 20 kHz ±0,15 dB
Input
Impedance: 0 to 100 Ω, user adj. 47 k Ω for MM
Equiv. Input
Noise: less that 1 nanovolt per square
root Hz
Gain: 40 dB MM at 1 kHz, 60 dB MC at 1 kHz
Line Section
Frequency
Response: 0,2 Hz to 500 kHz -3 dB
Input
Impedance: 10 k Ω
Output
Impedance: 100 Ω
Gain: 20 dB
Distortion: less that 0,05% THD or IM below rated output
Signal-to-Noise
ratio: greater than 92 dB A reffered to
rated output
Rated
Output: 5 volts RMS
Power Supply
Transformer: 30 VA encapsulated torodial
Capacity: 10,000 microfarads total
Voltage: ±48 volts DC
Output
Noise: less than 100 microvolts
Dimensions
(W x H x D): 483 x 318 x 95 mm (19"
x 12,5" x 3,75")
Weight: 13 kg (29 lbs)