Conrad-Johnson ET5 & LP125M – review of tube set for true connoisseurs of blues

Small description of the Conrad-Johnson ET5

Preamplifier ET5 implements the technology of the top model GAT Preamplifier at a more affordable price. The input stage of the device operates on a triode in class A, the output of the preamplifier is MOSFET-buffer. The ET5 has a power supply with a discrete voltage regulator. Infrasound noise is minimized due to the supply of tube filaments from a separate stabilized DC power source. The ET5 control functions are built on a microprocessor relay, the volume control on a matrix of precision metal film resistors. All switching and settings are made from the remote control. Useful mode “Theater Mode” allows you to include ET5 in the home theater system. The Theater Mode mode allows you to pass through the input signal with a single gain to turn the ET5 into a high-end home theater system without compromising its 2-channel performance. The model is made on audiophile element base. Dimensions of the amplifier are 390 × 483 × 125 mm, weight 12,4 kg.

The first stage of amplification is on a triode, which provides voltage amplification. This stage is connected to the preamplifier outputs via a high-current MOSFET buffer, which provides a very low output impedance, making the ET5 exceptionally flexible in the choice of inter-unit cables and amplifiers. The supply voltage is provided by a new stabilizer, implemented on discrete elements, reliably isolating the audio circuits from the mains voltage by supporting a negligible impedance throughout the entire audio frequency range.

Tubes are selected manually to achieve minimal noise and microphone effect. All other capacitors in the audio circuits and associated power supplies – polypropylene or polystyrene – there are no electrolytic capacitors.

Specifications of Conrad-Johnson ET5

Conrad-Johnson ET5

General characteristics
Type preamplifier
Standard stereo
Number of channels 2
Circuitry tube
Used Electronic Components tube 6922
Amp settings
Playable frequency range 2 – 100,000 Hz
Harmonics factor 0.15%
Signal to noise ratio 100 dB
Line In / Out
Output voltage 20000 mV
Output impedance 0.1 kΩ
Adjustments
Balance adjustment Yes
Interfaces
Inputs linear
Outputs linear, PreAmp, trigger
Gold Plated Connectors Yes
Power
Power Supply built-in
Transformer type W-shaped
Construction
Display Yes
Color design golden
Dimensions (WxHxD) 483x125x390 mm
Weight 12.7 kg
More Information
Features the tube can be replaced with RTET5

Conrad-Johnson ET5

Conrad-Johnson ET5 и LP125M

Developer notes.

“We have always tried to recreate the atmosphere of live sound – an uneasy task that requires a genuine passion and love for music. In the few companies that have succeeded in this, there has always been one or two enthusiasts behind the development “

William Conrad and Lewis Johnson

Conrad-Johnson ET5

What is inside?

In the ET5 model, the hybrid design tested in the flagship GAT preamplifier is used: the 6922 input tube provides amplification and high input impedance, and the field effect transistor at output – low output impedance. To adjust the volume and balance, an array of high-quality resistors are switched using a microprocessor-controlled relay with gold-plated contacts. The LP125M power amplifier is built on a two-stroke ultralinear circuit on a pair of pentods of 6550 in each arm, triodes 6922 at the input and M8080 in the intermediate cascade. In all amplifiers, signal circuits and power supplies lack electrolytic capacitors, which adversely affect sound. Instead, they use large-size film capacitors with a Teflon dielectric.

Interesting features

  • Price: $ 12,730 / $ 13,380 (per pair)
  • A miracle of design thought: Simplicity of the scheme in combination with the best components is the main secret of Conrad-Johnson
  • Interesting: America is the birthplace of the blues, and if you listen to Conrad-Johnson, you will feel it

It’s good that some things in the world do not change. The entire tube (and partly transistor) equipment of the American company Conrad-Johnson is imbued with the spirit of simplicity and nobility. Let engineers and marketers list the advantages of circuit solutions and element base. At a glance, the perforation of the protective grilles, the color and processing of the shell panels are enough to understand: this is the real thing. At the same time – unlike many similar devices – quite suitable for modern life.
Dual 6550 tubes in the output stage of monoblocks allow them to develop sufficient power for almost any speaker – 125 W. And the only thing you should take care of is the good cooling of the room where the equipment will be installed. The maintenance is reduced to setting the mode of output tubes every six months or after their replacement – this does not require special devices, since each is equipped with an LED indicator.

Do not rush to draw conclusions about the sound of this kit – almost any tube device requires addiction.

In the case of Conrad-Johnson, this caution will be even more pressing, as its performance is very smooth and natural, without any coloring or artificial beauty that could prompt you to fall in love with it right away. It is exactly as stated in the corporate slogan: “It just sounds right”. Take the time and effort to select suitable inter-unit and acoustic connectors (it is better to avoid products with a soft, relaxed character – in our system, good results were obtained by Nordost’s “quick” cables). Pay attention to the power supply – and you will find that the set has a well-defined, well-designed sound, with well-controlled basses and clear highs, a deep and filled sound stage. However, unlike many transistor competitors, Conrad-Johnson is not stingy in timbre colors, it is free and wide in spirit.

Good, but not for everyone

Does this mean that it will suit everyone? By no means. Our impressions from the sound of different CDs were very contradictory. The equipment with such expressed genre preferences does not often come across, but in the case of Conrad-Johnson it is difficult to identify them right away.

It’s easy to guess that the set perfectly works American music – the blues album of J.J. Kale and E. Clapton “Road to Escondido” conquers with energy, rhythm, beauty of solo guitars and skillful instrumental accompaniment. It’s quite natural that the classic of rock, for example the Machine Head of Deep Purple, is transmitted with that special drive and relish, in the search for which listeners often turn from digital media to vinyl discs.

However, it is not immediately clear why Conrad-Johnson masterfully, rhythmically and subtly plays out Jacques Loussier’s jazz improvisations to the music of baroque composers or Bach, and at the same time monotonously, blurryly reproduces cantatas of the same Bach performed by Cantus Colin. The thing is that the first music requires unconstrainedness, improvisation, which Conrad-Johnson and his compatriots have in their blood, and the second – of directly opposite performance qualities: accuracy, rigor and proportionality, the birthplace of which is the academic Old World. Now it becomes clear why this set is much better sounded live recording of Patricia Barber in Paris, and not recorded in the studio. And of course, we do not want to say that if you are going to deeply feel Beethoven’s symphonic music, Conrad-Johnson is far from the most successful option, although it is not devoid of some purely tube-like timbre attractiveness.

If you like blues, jazz, swing, big band, classical rock, prefer to be drawn to live recordings – with Conrad-Johnson you along the way and you will not regret for a moment about the money spent. If your musical preferences are different or just wider, you should pay attention to more universal options.

Pros

A rich sound with a large texture and a wonderful sense of rhythm.

Cons

Demanding power supply; accuracy and refinement are not their forte.

Conclusion

Amplifiers with strong genre predilections – for fans of blues, jazz and in general any music based on improvisation.



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