Up for sale is my CJ Evolution 2000 Zero Feedback Hybrid Amplifier. It's the pride of my system but I can no longer justify its size in my current room. Rated 7/10. Functionally, it is excellent. The amp uses 5751s tubes on the input stage and solid state mosfet on the output. Front is clear, very good clean condition. Top and sides are also like new. Two rear fins were bent during first shipment, but I re-straigtened them. Will provide photo upon request (hard to move the amplifier out from its stand). You will be hard pressed to find an EV2000 in this condition nowadays.
If a company made this caliber of an amplifier today, it would cost well over $10K.
Matched quad of GE 5751s installed, maybe 50 hours on them. Will include another matched quad with a bit more time on them as backups. Comes with original owners manual and original shipping crate. Note that buyer will need to work with me to coordinate shipment as this amplifier is monstrous. Sold as-is, but guaranteed against DOA. Please add 3% for PayPal.
Also check my listing for the matching Premier 9 DAC and Premier 10 Pre.
From CJ: The Evolution 2000 was a genuinely unique design drawing on the many year's experience conrad-johnson had with both vacuum tube and solid-state circuits. The EV2000 uses MOSFETs for output devices and vacuum tubes for the input stage making the EV2000 a truly hybrid design. It was a straightforward response to the challenge of producing a true zero-feedback power amplifier. Since only square-law valves are deployed in the EV2000, only second order distortion products are produced. Odd order distortion components, which are most noticeable and objectionable to the human ear, are virtually non-existent. Triode vacuum tubes were selected to provide all of the voltage gain. Current gain is provided by two stages of complimentary MOSFET source followers, the final stage consisting of five-pairs of high current devices for a nearly unlimited capacity to deliver current into reactive loudspeaker loads. High current delivery was facilitated by a massive, oversized, dedicated power transformer (nearly 50 lbs.) used for the solid state output devices. The MOSFET output stage eliminated the bandwidth limitations and phase shift associated with output transformers, and at the same time achieved a much lower output impedance than would be possible with a vacuum tube output stage. The EV2000 offered the tonal integrity of the finest vacuum tube amplifiers combined with the speed and detail of superior transistor designs. Individual voices and instruments are faithfully reproduced and remain tightly focused on the soundstage no matter how complex the musical passage.
Power switch, left and right RCA input jacks, and left and right output jacks (5 way binding posts)
Power Output - 200 watts per channel from 20Hz to 20KHz with no more than 1% THD or IMD, both channels driven into 8 ohms.
Input Sensitivity: 900mV to full power
Response: 20Hz to more than 20kHz , +0, -.5dB
S/N Ratio: 96 dB relative to max output
Dimensions: 22" X 19"W X 10" Weight 114 lbs (unboxed).