• Virtus-01v2-front-top
  • Virtus-01 – Headphones OTL Tube Amplifier-tubes-bright
  • Virtus-01 – Headphones-OTL-Tube Amplifier-side-top
  • Virtus-01 – Headphones-OTL-Tube-Amplifier-tubes
  • Virtus-01-interior-1
  • Virtus-01-interior-2
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Virtus-01 – Headphones OTL Tube Amplifier

Virtus-01- OTL Single Ended headphone amplifier (without output transformer, class A) in the Dual Mono architecture. The use of the KT88 / KT120 / KT150 tetrode power tubes allows this device to work with many dynamic headphone models as well as some planar headset models. As standard, 6922 EHG or equivalent of the popular ECC88 are used as driver tubes. The sound of the model is a warm, spatial and offers dynamic sound characteristic from electron tubes with a lot of details, which can be modified if necessary by using different models of tubes. The midrange and treble are fed in a natural, non-irritating way so that even prolonged listening to music does not cause fatigue.

  • Type: tube, class A, triode, tetrode, OTL
  • Power output at 85Ω load:
    • 2 x 1W (KT88); 2 x 1.2W (KT120); 2 x 1.5W (KT150)
  • Input impedance: 50kΩ
  • Amplitude of input voltage: 2 V – 12 V (max)
  • Anode power supply: 250 VDC
  • Heater: 6.3 VAC, 6.3 VDC
  • Load impedance range: 24Ω – 600Ω
  • Inputs: 1 x RCA Stereo
  • Outputs: 1 x TRS Stereo
  • Power consumption: 200W
  • Fuse: 3.15A
  • Weight: 13 kg
  • Dimensions: 305mm (W), 400mm (deep), 80mm (H)



The amplifier offers control of the sound by changing the tubes. The most important influence on changes in the character of the sound has a single driver tube, followed by a pair of power tubes. In the Virtus-01 amplifier, all equivalents of ECC88 tubes can be successfully used as a control lamp and KT88 / KT120 / KT150 equivalents as a power / output stage lamp. Tubes can be replaced without interfering with the interior of the amplifier.

Virtus-01 has Dual Mono construction — each channel, apart from being a completely separate amplifier, has four independent power supplies supplying power to selected sections of the system. To ensure the best operating conditions, the power supply of the driver tubes provide their heaters direct current. The filtration completely eliminates the disturbances of the power network and ensures precise working voltage. Two toroidal power transformers are made in technology used in audio equipment (elimination of transformer hums). Complete separation of the amplifier channels through eight independent power supplies and two power transformers offer space and stage at the highest level. KT lamps are known for their dynamic and precise sound. They are very versatile and work well in any musical style. The sound is warm, detailed and massive.

Virtus-01 has in each channel a tube voltage amplification stage and buffer amplifier realized on the 6922 EHG lamp. KT tubes work in a duplicate system where the signal from their cathodes after passing through the output capacitors is fed to the headphones.

All ECC88 tube counterparts can be used in the ECC lamp section, eg 6922, 6N23P, 6N23P-EW, 6DJ8 etc. The tube lifetime of this type can reach up to 10,000h.

Virtus-01 works with headphones with an impedance range from 24Ω to 600Ω. Its optimum match in terms of load is obtained with headphones with an impedance of around 100Ω, but thanks to the large reserve of output power it can also work with headphones with a higher impedance than rated.

The operation mode without the use of output transformers ensures the highest precision of sound and least distortion. The output of both channels is made of power tube cathodes after passing through Nichicon KZ Muse signal capacitors dedicated specially for high quality audio devices. Three types of tubes can be used in the power section of the Virtus-01 amplifier: KT88, KT120 and KT150. It does not require any changes in the amplifier system, because Virtus has an auto-bias system that allows its electronics to be adjusted to the type of lamps used. The maximum output power of the amplifier closes from 2 x 1W for KT88 through 2 x 1,2W for KT120 to 2 x 1,5W for KT150. This makes it possible to use Virtus also as an amplifier for planar headphones, whose impedance is similar to its output impedance, that is around 80Ω – 120Ω. For planar headphones that require more power output from the amplifier, we recommend our AB class models that offer a power of over 10W per channel.

Virtus-01 is made in a solid metal casing standing on aluminum legs with a rubber stabilizing the amplifier on the base on the bottom. On the front panel there are illuminated analogue VU meters, of which tips swing dynamically to the rhythm of the music. The amplifier can be optionally equipped with an additional pair of XLR connectors (stereo input), as well as an attenuator (48-step resistor ladder from the Polish manufacturer Khozmo Acoustic). The network connector is an IEC type socket.

Additional information

Weight13 kg
Dimensions40 × 30.5 × 8 cm