DNA Stratus Headphone Amplifier with Additional Tubes for sale. Over excellent condition, fingerprints easily in images. Truly a wonderful amp but I have too many nice amps at the moment. Pairs wonderful with ZMF Headphones and many others. Payment via PayPal invoice only.

I do not have the original box or instruction manual, but I will pack the bejeezus out of it for it to arrive to you safely. See my feedback on USAM for confidence. Shipping will be $220 for anywhere in CONUS, insured for full value. I will include a basic stock power cord as you will likely upgrade it anyway. Currently, these are on an 10/12-month backorder from Donald North Audio. Skip the wait and buy this one, then tube roll to your heart's content.

Comes the following tubes:

1. National Union 5U4G (x1)
2. RCA 5U4G (x1)
3. 2A3EH Electro Harmonix (x2)
4. 2A3B Electron Tube (x2)
5. PSVANE A2A3 black base (x2)
6. Brinmar 6158 (England) (x1)
7. Tubemonger tube vibration dampner (x2)


From the DNA Website:

The DNA Stratus vacuum tube headphone amplifier is specially created to drive all dynamic headphones with the life-like fidelity uniquely provided by the 2A3 directly heated triode. The 2A3 is my all-time favorite directly heated triode vacuum tube and is normally used for powering high efficiency loudspeakers. It has a pure, natural presentation with "you are there" tangible presence.

Many speciality audiophile headphones including the AKG K1000, Audeze LCD-2 & LCD-3, HiFiMAN HE-5LE, HE-500 & HE-6 are lower efficiency than conventional headphones and require higher gain and power to show their true beauty. The 2A3 is my first choice for powering these challenging headphones with stunning performances.

The Stratus works wonders with many audiophile headphones.

Design features include:

• Purist class A single ended triode design

• Output transformers custom made to DNA's specifications in the USA

• Flat and extended frequency response with very low distortion

• Zero feedback or other error correction trickery
Triodes are naturally low distortion when operated into a high impedance load such as a transformer with proper specifications. They do not require feedback to attain low distortion.

• Point-to-point hand wired audio circuitry using carefully selected audiophile components

• Quasi-dual mono power supply with separate filter chokes and capacitors for left and right channels

• Dual 3-pin & 4-pin XLR and 1/4" stereo TRS outputs

• All XLR and 1/4" TRS outputs provide the same power: 1.8W into 50 ohms, 900mW into 100 ohms

• 4-pin XLR output can be used with all headphones - not just the K1000 only. I labeled it "K1000" in honor of the legendary headphone which was the inspiration for developing the Stratus.

• XLR outputs are selectable between unbalanced (single ended) and balanced headphone drive

• XLR outputs have 8 ohm output impedance

• 1/4" stereo TRS output has selectable gain attenuation between 0dB and -6dB for greater volume control range on higher sensitivity headphones

• 1/4" stereo TRS output on full gain, 0dB attenuation setting has selectable output impedance between 8 ohm (Low setting) and 120 ohm (IEC setting)

• 1/4" stereo TRS outut on -6dB gain attenuation setting has selectable output impedance between 3 ohm (Low setting) and 115 ohm (IEC setting)

• Audio signal tubes are DC heated and 2A3 tubes include nulling pots for the quietest noise floor

• Balanced choke-filtered 2A3 filament supplies provide a deep black background and outstanding layering

• 2 sets of RCA unbalanced inputs with rear toggle switch

• TKD volume control potentiometer


Stock tube complement:
1- Winged "C" (SED) 5U4G rectifier
1- Sovtek 6N1P dual triode input/driver tube
2- Shuguang 2A3B directly heated triode power tubes

Input impedance: 50Kohms

Dimensions: 8.5 " H x 17" W x 14 " D (21.6cm H x 43.2cm W x 35.6cm D) including tubes and connectors & controls.