Consistent with conrad-johnson's design philosophy that circuits should be kept as simple as possible, the LP66S works its magic with just seven vacuum tubes. A composite triode input stage is direct coupled to a cathode-coupled phase inverter – the same improved wide-bandwidth driver stage found in our other, more costly LP amplifiers. The output stage is comprised of a pair of 6550s operated in ultralinear configuration for an optimal combination of high power and low distortion. Limited negative feedback is applied to the circuit to reduce distortion and provide a sufficiently high damping factor to control most real-world speaker systems. Discrete dc power supply regulators are provided for the input and inverter stages, in order to isolate each stage from the output signal.
As with all conrad-johnson tube amplifiers, the LP66S requires 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 adjustment using only the supplied screwdriver.
Component parts quality is a signature strength of any conrad-johnson product. Audio circuit and related power supplies feature precision metal film resistors and high-performance polypropylene 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 input/output connectors and internal wiring have been carefully selected for optimal sonic performance.
Conservatively rated at 60 watts per channel, the LP66S offers sufficient power for most applications. Users who have not previously experienced the dynamic range and lifelike timbre of tubed components will find the LP66S an ideal introduction to the joys of modern tubed amplifiers. Along with its tonal integrity, its ease of use, low maintenance costs, and reliability will be a revelation for those who have only experienced "entry-level" tube gear. For veteran audiophiles, its modest price and size make it a great choice for bringing conrad-johnson quality to a "second” system. A word of warning if you are in this last group: whether in the den, library, or bedroom, the LP66S’ wide bandwidth and low distortion will give your main system a run for the money.
We invite you to visit conrad-johnson dealer to audition an LP66S and perhaps rekindle your passion for enjoying great music in your home.
Specifications
Power:
LP66S - 60 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: 0.5 V to rated power
Frequency Response (at 10 watts): 20 Hz to 20 kHz, +/- .25 dB
Hum and Noise: 102 dB below rated power
Input Impedance: 100 kOhms
Tube Complement: 3 x 6922, 4 x 6550
Dimensions: 16D x 19W x 6.38H inches
Weight: 45 Lbs.
All conrad-johnson products are carefully hand assembled and each is thoroughly tested to assure conformity to our exacting performance standards. Our confidence in these components is reflected in our three year limited warranty covering labor and parts. Service is a top priority at conrad-johnson. In the event that a product does require service, it will be handled promptly and efficiently.
C O P Y R I G H T © 1 9 9 8 -- 2 0 0 8 c o n r a d j o h n s o n
conrad-johnson design, inc. 2733 Merrilee Drive Fairfax, VA 22031
phone: 703-698-8581, fax: 703-560-5360