Conrad Johnson Tube Amplifiers:

The Conrad Johnson MV60 Tube Amplifier A stereo amplifier, the MV60 uses two EL34 tubes a side to generate 55 watts a channel in standard, ultralinear mode. And just as both the Premier 11a and the MV55 had triode models, so too can the 60 be wired for triode, in which case the output is 25 watts a channel. With a 6SN7 driver tube and a 12AX7A input tube a side, the design is not radical; rather it is evidence of many years of refinement and as such it is the obvious and deserved heir to both older amplifiers. But where the MV60 differs most from the MV55 and also directly bridges to the more expensive 11a, is in the use of the same transformers that were in the now discontinued Premier model.

The Conrad Johnson Premier 140 Tube Amplifier is the first Premier amp voiced from scratch with an all-Russian tube lineup. An obvious rationale is that the Svetlana 6550C is in production and available, while the GE 6550A -- C-J's power tube of choice for the predecessor Premier Eight and Twelve -- is not. Sonically, the 6550C is known for tighter bass, superior resolution, and grainless, extended highs. Implementation based on listening is key to avoid the Svetlana sounding lean and mechanical. Happily, these issues play to Conrad-Johnson's strength for design execution.

The Conrad Johnson ACT2 Tube Preamplifier The elegant composite triode circuit that Conrad-Johnson used in the ART, and now in the Conrad Johnson ACT2, has been described frequently in the literature, so I won't repeat what you can read on the Conrad-Johnson website and elsewhere. Like the ART, output impedance is just under 500 ohms. Audio and control circuits each have their own power supplies, and, according to C-J, the ACT2 makes generous use of polypropylene, polystyrene and Teflon capacitors in both. Where the ART required two chassis to house its five tubes per channel, the Conrad Johnson ACT2 fits itself within a single box -- no doubt shaving costs and keeping signal paths short. Indeed, its $13,500 USD price tag is lower than the ART's. While that's still a heap of money, it is refreshing to see reference-quality componentry actually come down in cost.

The Conrad Johnson ART Tube Preamplifier How do I even begin to assess the ultimate value of Conrad-Johnson's ART? Fifteen thousand dollars is a lot of money by any reckoning. But the ART belongs in that very small class of products without peer, and the best of anything does not come cheap. If you must have the best, and if the rest of your system also exists on that exalted plane, then you will be very---exceedingly, even---happy with the ART. It is without compromise. And as for the rest of us, well . . . we can always dream, can't we? The ART Preamplifier is a vacuum-tube, line-stage preamplifier in a true dualmono configuration, with completely separate right and left chassis. The unit features input selection and level adjustment by microprocessor- controlled relays. A data link, which is isolated from the audio circuitry and grounds of the two channels, connects the two chassis to enable a single set of controls to operate both channels, eliminating the bothersome dual volume controls that are the bane of conventional dual-mono designs. Level and balance can be adjusted in 100 steps of approximately .66 dB per step. All functions can be controlled by the hand-held wireless remote control.

The Conrad Johnson EVOLUTION 2000 Tube Amplifier 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. 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.