WooAudio GES Electrostatic Stax Earspeaker Amplifier

GES works with all 5-pin Pro bias Stax Earspeakers.

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WA GES - electrostatic headphones amplifier, recommended driver for Stax Pro bias, HE90, and compatible headphones

Rear panel. From left to right: AC inlet, AC110/220 switch, input 2, source selector, and input 1

front row tubes are 12AX7 and back row tubes are 6S4

The first thing I noticed about these headphones is that they have A LOT of bass. Coming from a history of mostly generally considered bass light headphones, this is a whole different cup of tea.

The GES retains the detail - the distinct placement of instruments and voices within the mix but is not hard or harsh in its analysis - it's still warmly musical, seductively so. It's just a good, neutral and clear deliverer of what it's being fed.

* Power cord and interconnection cables are not included.

* Shopping cart applies to the U.S. buyers only. International buyers please contact us for shipping cost and payment instruction.

Technical Specifications:

Input impedance: 100 Kilo-Ohms
Frequency response: 10 Hz - 80 KHz, -3dB
Signal/Noise: 100 dB
Bias voltage: 580VDC
THD: <= 0.1%
Voltage: AC 110/220V, 50/60 Hz
External dimension: 6½(H), 13"(W), 10½"(D)
Weight: 22.5 lbs

Standard Featurs:

Point-to-Point Wiring
Four 12AX7 [PDF] drive tubes
Four 6S4 [PDF] power tubes
Two selectable RCA inputs
High-performance Solen and WIMA capacitors
Heavy-duty full aluminum die-cast chassis, anodized finished
Whole aluminum volume knob and power switch button
Two Filter chokes
140 watts power transforme
Gold-plate RCA
Alps potentiometer and power switch
Teflon wires

Schematic re-engineering is based on Dr. Gilmore's design.

Sennheiser HE-90 connector:
HE-90 is an add-on option, shown in this picture. $200

Sennheiser HE-90 output sold with GES purchase.

Parts upgrade:
Premium parts upgrade package. $680

We carefully selected the best possible audiophile graded parts that bring the ultimate performance from the amplifier. Parts upgrade are intended for amplifier purchase, not to be sold on a standalone basis.

Auricap interstage coupling caps, 0.22uf/400V
Auricap output coupling caps, 2uf/600V

Attenuator upgrade:
DACT CT2 stepped attenuator. $215

24-position, high accuracy and reliability

Teflon tube sockets upgrade:
$300 (9-pin x8)
Teflon is a superior material with great isolation and tempreture endurance. The unique design of multiple pin contact area greatly increase connectivity and gripping. Pins are gold-plated over oxygen free copper.

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Drive tube replacement:
1 matched quad Ratheon 12BZ7 $64 (4 pcs)
(ship in separate package)

NOS tubes. 12BZ7 is a direct replacement tube for a 12AX7.