Woo Audio 3 High End Headphone / Pre Amplifier

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Out of the box this is a rewarding and enjoyable auditory experience. The price belies the value you are receiving. This amp is dimensional, tonally very musical, i.e.: as in real music.

Probably one of the best audio buys I've ever made and I've always been a solid state guy. This amp just makes magic with HD-650's.

The image is fairly dimensional, with a wide, deep and high soundstage, which allows you to sense the relative positions of the instruments and performers. The amp positions the listener fairly close to the performance with a more intimate sound – closer to the front row, or stage, than to the back rows.

The most notable difference seemed to be the soundstage, it is HUGE. I can easily tell from what direction all the voices and instruments are coming from now. The vocals (and entire midrange) have superb seperation, and seem to carry more weight or "authority".

* 1 pair of drive tubes, and 1 power tubeare included.

* AC Power cord and RCA interconnect cables are not included.

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

Headphones impedance : 30-600 Ohms
Input impedance: 100 Kilo-Ohms
Frequency response: 8 Hz - 100 KHz -3dB
Signal/Noise: 95 dB
THD: <= 0.08%
Pre-amp Gain: 10 dB
Voltage: AC 110/220V, 50/60 Hz
External dimension: 6"(H), 5½"(W), 13"(D)
Weight: 10 lbs

Point-to-Point wiring
One 6AS7 / 6080 [PDF] power tube
Two 6922 / 6DJ8 [PDF] drive tubes
One RCA input
One pre-amplifier output
¼" stereo headphone jack
Full aluminum die-cast chassis, anodized finished
Whole aluminum volume knob and power switch button
80 watts specially made toroidal transformer
Gold-pin tube sockets
Gold-plate RCA
Alps potentiometer and power switch
Rubycon and WIMA capacitors
Dale and Vishay high precision resistors
Teflon wires

Teflon tube sockets upgrade:
$75 (9-pin x2, 8-pin x1)
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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Power tubes upgrade:
Tungsol 7236 NOS $55 each

One of the best power tubes available for this amp. The 7236 vastly improves dynamic and soundstage. It has a very good speed, warm mid range, tight and deep bass. Buy and ship separately.

Driver tubes backup:
Hand-pick matched pair
Philips 6922 JAN $40 (2 pcs)

Low noise, smooth. Military grade, Joint Army Navy (JAN) tube. Buy and ship separately.

An excellent value and performance for high impedance or high sensitive headphones