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Conrad-Johnson Premier 140
SOLD $10,000.00
SEPT
2009
SoundStage Review
Manufacturer's Website
The Premier series of conrad-johnson products are
precision music reproduction instruments designed to meet the needs of
audio industry professionals and other audiophiles who require near
perfection from their reference systems. The latest in the highly
regarded Premier series of vacuum-tube power amplifiers, the Premier 140
is the proverbial iron hand in a velvet glove - capturing delicate
textures and subtle nuances while demonstrating muscular power,
authority and control.
The Premier 140 audio circuit consists of three
stages. The input signal is amplified by a single-ended triode amplifier
designed for wide band-width. The signal is then direct coupled to a
cathode coupled phase-inverter. This high current, triode phase-inverter
stage provides a balanced, low impedance drive to the output stage.
Output power is developed by two pairs of 6550s per channel, chosen for
their excellent sonic character, high power, and reliability. The output
tubes are operated in ultralinear configuration which offers a desirable
combination of high power and low distortion. Massive output
transformers with intricately interleaved windings afford extended
bandpass and high phase linearity. A small amount (about 12 dB) of loop
negative feedback reduces distortion and achieves a sufficiently high
damping factor to control reactive loudspeaker systems.
Power supply design is every bit as critical to the performance of an
audio component as the audio circuit itself. In the Premier 140,
separate, low impedance, discrete dc power supply regulators are
provided for the input and phase-inverter stages, preventing the output
stage from modulating these stages through the power supply The main
power supply reservoir uses a bank of massive custom polypropylene
capacitors. No electrolytic capacitors are used in any of these power
supplies.
The Premier amplifiers require no complicated adjustments or specialized
equipment to maintain. To assure continued peak performance, the owner
need only make a simple bias adjustment when new tubes are installed.
Built in LED bias indicators allow the user to make this adjust-ment
using only the supplied screwdriver.
At conrad-johnson we are keenly aware that component parts contribute
importantly to the sonic performance of any circuit design. The Premier
140 amplifier maintains the exacting quality standards for which
conrad-johnson is internationally known. Resistors are precision
tin-oxide deposited on glass and bulk metal foil. All audio-circuit
capacitors are polystyrene, while the power supplies use large value
polypropylene in parallel with polystyrene capacitors. There are no
electrolytic capacitors in the audio circuits or in the related power
supplies. Proprietary wide-bandwidth output transformers contribute to
excellent high frequency performance. Even the machined gold plated OFC
connectors and the internal wiring have been carefully selected for
optimal sonic performance. Attention to details of this kind enable us
to extract the full potential from our circuit designs and ensure that
our products will perform to this potential for years to come.
Specifications:
Premier 140 Vacuum-Tube Power Amplifier
Power: 140 watts per channel from 30 Hz to 15 KHz at no more than 1.5 %
THD or IMD, both channels driven into 4 ohms (also available connected
for 8 or 16 ohm loads) Sensitivity: 1.1 volt rms to rated power
Frequency Response (at 10 watts): 20 Hz to 20 kHz, +/- .1 dB
Hum and Noise: 104 dB below rated power
Input Impedance: 100 KOhms
Tube Complement: 1 6922, 2 6N30, 8 6550
Dimensions: 19D x 19W x 8H inches
Weight: 85 Lb.
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