For your consideration, we have a one owner Conrad Johnson CT5 Composite Triode Preamplifier, in perfect working and like new physical condition. We are big fans of Conrad Johnson, and we loved having this Preamp in our shop. Note that this preamp is linestage only, so a separate Phono Preamplifier will be required to use a turntable. Coming from a home with no pets, smokers or kids, we were unable to find any blemishes or marks on the unit. See pictures for further details. The serial number as pictured is 2851092. Included with the preamp is the original box, with original packing, owners manual, remote control, AC cord, nut driver (to unscrew tube guards in order to replace tubes), 4 tube dampers, and two sets of tubes. The original set of tubes were replaced in 2015, with a pair from Conrad Johnson. The owner stated that he just figured it was time to get new tubes, but noticed no difference in sound. Testing on our Amplitrex AT1000 tube tester showed why he noticed no difference in sound as all four tubes showed minimal wear and tested as practically new.
From the Conrad-Johnson website:
The composite triode circuit is a conceptually simple design—based on creating a single “super” triode by paralleling sections of individual tubes. In this way, the entire amplification circuit can be reduced to a single active stage, without buffers or feedback. Any active circuit element will color the sound, whether the element is an amplifier or a buffer stage. By designing a line stage consisting of a single composite triode, we are able to reduce the circuit to the absolute minimum of a single active element. The result is an astonishing improvement in dynamics and dynamic shadings, as well as focus.
In the CT5, the composite triode is comprised of two paralleled sections of ultra-high transconductance miniature twin-triode tubes.
This circuit achieves a sufficiently low output impedance to drive most interconnect/amplifier combinations while eliminating any circuit element that might compromise its sonic purity. To realize the full potential of this amplifier stage, it is powered by a sophisticated discrete voltage regulator designed to completely isolate the audio signal from the power line.
All control functions of the CT5 operate through microprocessor-controlled relays.
For the level control, the relays select combinations from a network of precision, low-noise metal foil resistors to effect loudness and balance changes in 100 steps of approximately .7dB per step. All switching and adjustment can be controlled by the unit’s remote control. A Theater mode, which passes the input signal through at unity gain, makes it simple to incorporate the CT5 into a high quality home theater system without compromising its two-channel performance.
Like its bigger brother, the ACT2, the CT5 is constructed from the highest quality, carefully selected parts for unrivaled sonic performance and reliability.
The same CJD Teflon capacitors that distinguish the ACT2 are used in the CT5 for output coupling and post-regulator power supply storage. All other capacitors in the audio circuits and related power supplies are polypropylene or polystyrene, and the resistors in these circuits (including the level control) are special low inductance, high-precision laser-trimmed metal foil resistors. Switches are sealed relays with gold-plated silver contacts. Input and output connectors are premium quality custom machined parts.
In our quest to recreate the glory of music without compromise, we at conrad-johnson are dedicated to bridging the gulf between craft and art to create audio amplification components that do credit to music performances.
Through meticulous engineering, careful specification of only the finest available component parts, and a painstaking attention to construction, we have created what we feel is a line-stage without rival in its class. We invite you to arrange an audition of the CT5 with your conrad-johnson dealer to experience the extraordinary musical performance of this remarkable preamplifier.
Gain: 20 dB
Maximum Output: 10 vrms
Output Impedance: 800 Ohms
Distortion: less than .1% THD at 1.0 Vrms output
Frequency response: 2 Hz to more than 10OKhz
Hum and Noise: 100 dB below 2.5 V
Tube complement: 2 x 6N30P
Dimensions: 15.5D x 19W x 5H inches
Weight: 31 lbs.