The amplifier offers the possibility of creating the sound individually 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-300B amplifier, all equivalents of ECC88 tubes can be successfully used as a driver tubes and 300B equivalents as a power / output stage tube.
Virtus-300B has a 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. 300B power triodes are making sound warm but not slowing it down and they do not lower the resolution. Virtus-300B has in each channel a tube voltage amplification stage and a current follower (the so-called buffer) realized on the 6922 EHG tube. 300B Tubes work in a repeater system where the signal from their cathodes after passing through the output capacitors is fed to the headphones.
All ECC88 tube equivalents can be used in the ECC tube section, eg 6922, 6N23P, 6N23P-EW, 6DJ8 etc. The lifetime of this type of tubes can reach up to 10,000 hours.
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 to specially high quality audio devices.
In the power section of the Virtus-300B amplifier, various types of 300B tubes can be used. It does not require any changes in the amplifier system, because Virtus has an auto-bias system that allows its electronics to be automatically adjusted to the type of tubes used. The maximum output power of the amplifier is up to 2 x 1W.
Virtus-300B 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, the tips of which 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 IEC connector is a network connector.