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Introduced in 2009, the GAT Preamplifier continues conrad-johnson’s dominant position atop the rankings of reference preamplifiers. An important benefit of pursuing state-of-the-art designs is that the circuits and techniques developed in their flagship products are frequently directly applicable to their entire line of products. In this instance, they have embodied the technology of the GAT Preamplifier in the more cost effective ET5 enhance triode line-stage preamplifier at a more affordable price.
The circuitry of the ET5 follows closely that of the GAT line-stage preamplifier. The audio circuit is elegant in its simplicity. An audio amplifier stage consisting of a single-ended triode amplifier provides the voltage gain. This amplifier stage is connected to the preamplifier outputs through a high-current MOSFET buffer, which achieves a very low output impedance, making the ET5 extremely flexible in the choice of interconnect cables and amplifiers. DC voltage is supplied to the circuit by their latest discrete voltage regulator that isolates the audio circuit from the power line by maintaining negligible impedance across the audio frequency band. Infra-sonic noise is minimized by operating the tube filaments (heaters) on a dc voltage supplied by a separate regulated power supply. The ET5 is also notable for convenience and ease of use. The unit features input selection and level adjustment by microprocessor-controlled relays, with controls available both at the front panel and via a full-function remote. All control functions of the ET5 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 ET5 into a high quality home theater system without compromising its two-channel performance.
Like its bigger brother, the GAT, the ET5 is constructed from the highest quality, carefully selected parts for unrivaled sonic performance and reliability. Tubes have been carefully hand selected for minimum noise and microphonics. The same CJD Teflon capacitors that distinguish the GAT are used in the ET5 for output coupling and post-regulator power supply storage. All other capacitors in the audio circuits and related power supplies are polypropylene or polystyrene – there are no electrolytic capacitors in the audio related circuits. The resistors in these circuits (including the two dozen level control resistors) 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.
For more than three decades, they at conrad-johnson have been dedicated to creating audio 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, they have created what they feel is a line-stage without rival in its class. they invite you to arrange an audition of the ET5 with your conrad-johnson dealer to experience the extraordinary musical performance of this remarkable preamplifier.
Every conrad-johnson ET5 Line-Stage Preamplifier is patiently and carefully hand assembled, then individually inspected and its performance verified by an experienced audio technician. The owner is protected by their three year limited warranty covering labor and parts except vacuum-tubes. Service is a top priority at conrad-johnson. In the event that a product does require service, it will be handled promptly and efficiently.
- Gain: 25 db
- Maximum output: 20 vrms
- Output impedance: 100 ohms
- Distortion: less than .15% THD at 1.0 Vrms output
- Frequency response: 2 Hz to more than 100Khz
- Hum and noise: 100 db below 2.5 v
- Phase: phase inverting
- Tube complement: 6922
- Dimensions:375D x 19W x 4.94H inches
- Total weight: 28 lbs.
“… I can only think of about six preamplifiers that outperform the ET5. They all have a price that costs two-to-five times greater, and half of them are C-J designs. If that doesn’t say Exceptional Value Award for 2011, nothing does. Highly recommended.” — Jacob Heilbrunn (Tone Audio)