Classical lamp power amplifier, with the inherent characteristic volume, low-soft, warm juicy middle and moderately soft but expressive highs.
Prefix GC - means that it is improved in sound and performance lamp 6L6 / 5881, with a little more body and thicker walls, extended-voltage potential applied to the grid (up to 600V). It is worth paying attention to it, as many amps to work with GC modifications and other modifications may sound light with overdrive and a reduction in service life. In contrast to the Russian analogues, it has a more expressive and musical sound, combining high reliability.
Like all power-lamp during the operation can reach high temperatures and will serve much longer and retain its characteristics, subject to the necessary warm-up, ventilation and absence of vibration amplifier housing.