Johnson ET5 tube preamp - $4,850. Retail
price is $10,000. This reference level preamp is in mint condition. Giving it a 9/10 as it is over 1 year old. I am selling as I am downsizing my system. The preamp currently
has a Telefunken E88CC/6922 cryogenically treated tube, which provided across
the board improvement. Well worth its
$200.00 cost. The original tube will be
included. Also included is the original shipping box, packing, remote, power
chord and owners manual.
Buyer pays shipping and Paypal fees
output: 20 vrms
impedance: 100 ohms
less than .15% THD at 1.0 Vrms output
response: 2 Hz to more than 100Khz
and noise: 100 db below 2.5 v
15.375D x 19W x 4.94H inches
weight: 28 lbs.
Dimensions: 25 x 22 x 12. Weight 34 lbs.
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 our 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.
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.