attitube

Virgil Tube Laboratories just finished the second version of their  all tube  fully balanced line amplifier last week. Compared to the previous one, named VLP62oB , the new V20 is not supporting a phono stage at all and makes use of  Russian made vacuum tubes 6N23P, long life versions. Considerable improvements were made at the power supply stages. VP20 is using a slow rise  B+ regulator in order to deliver the anode tension progressively from zero to full B+ potential in about 10 seconds, simulating the behavior of a EZ80 rectifier; the filament supply is working in the same manner, providing a 30 seconds slow rise from 2/3 of  filament nominal voltage (4 Volt) to full value (6,3 Volt). The filament and B+ power supplies  start-up, stand-by and delays are logically correlated this way: first, the filament is heated at 4 Volts, then the filament voltage rises slowly to full value, then the B+ is delivered progressively and after reaching full value, the mute relay is opened.  Practically, someone could left plugged the V20 into the mains socket forever in stand-by mode, thus increasing the vacuum tubes lifespan.

Here there are few pictures presenting the V20 vacuum beauty:

                       Well done, Virgil!

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