ET3 Vacuum-Tube Preamplifier
At conrad-johnson, development of our flagship products has traditionally led to important enhancements of our entry-level offerings. The ET3 preamplifier is a case in point. The ET3 line-stage is a “baby” version of our flagship line-stage preamplifier, the GAT. The family resemblance is much more than skin deep. With voltage gain provided by a triode vacuum-tube, the zero-feedback line-stage circuit of the ET3, along with its DC voltage regulators, closely replicates the circuit of the GAT. Finally, and especially noteworthy, the ET3 features a relay operated discrete stepped attenuator level-control circuit of the type found in the GAT and CT5, absent only the balance control function found in those more costly models.
Functionally, the ET3 provides highly flexible I/O facilities with six separate line-level inputs (including one “tape” loop), plus a theater loop that facilitates use in a home theater system. In addition, the ET3 offers the convenience of infrared remote control of all functions.
For vinyl enthusiasts, the ET3 is optionally available with a vacuum-tube phono stage that borrows its zero-feedback audio circuit from our reference quality TEA1 phono stage. Customers can choose between high gain (recommended for cartridges with a rated output of 1.0 mV or less) and low gain (recommended for cartridges with rated output greater than 1.0 mV) versions of the phono stage. Input resistive loading is switch selectable over a range from 47 kOhms down to 200 Ohms. The ET3 phono stage is built to the same high quality standard found in the ET3 line-stage.
Premium quality component parts are specified to optimize performance and to sustain that performance for years to come. Precision, metal-film resistors yield low noise performance for greatest clarity. Polypropylene capacitors, used exclusively in the audio circuits and the regulated plate voltage supplies, offer extraordinary temporal accuracy. In fact, the ET3 is built to standards that meet or exceed those of many companies’ “flagship” offerings. Those who wish to take the performance to yet a higher level will be thrilled by the availability of an upgraded “SE” version. The ET3SE boasts CJD Teflon capacitors in critical circuit applications, dozens of upgraded metal foil resistors (including ALL resistors in the stepped attenuator level control), upgraded machined input/output connectors, and even an upgrade AC mains line-cord.
It would be fair to say that the only thing “entry-level” about the ET3 is its price. Arrange to audition one at a conrad-johnson dealer to find out for yourself – you’ll be surprised at just how affordable true high-end performance can be.
ET3 line stage
Gain: 25 dB
Maximum Output: 20 Vrms
Distortion: less than .15% THD
Impedance: 100 Ohms
Freq. Response: 2 Hz to more than 100 KHz
Hum and Noise: 98 dB below 2.5 V
Phase: phase inverting
Tube Compliment: 1x 6922
ET3 Optional Phono Stage
Gain: High Gain Version 54dB
Low Gain Version 40dB
RIAA Equalization: +/- .25 db 20Hz to 20kHz
Hum and Noise: -80dB relative to 10mV input
Phase: phase correct
Tube Compliment: High Gain Version 3x 12AX7
Low Gain Version 2x 12AX7, 1x 12AU7
Dimensions: 13.125D x 19W x 3.315H inches
Weight: 13 lbs.