THE Zeus 833A Mk2 tube amplifier monoblock x 2 * 300B drive input 117V, 230V

This is upgrade version from The Zeus 833A that using 211 tube as drive
tube. Drive tube change to 300B, to make sound more musical and clear in
middle range.

The reason that I change drive tube to 300B is
using 211 drive 833A make sound full of power but lack the musical and a
little dry in middle range and high mid range. Changing drive tube to
300B make sound more clear in middle range and the most important thing
is make sound more musical, sweeter and detail.12Y7 is adopted as
prestage because it is best matching with 300B.



All 833A is very huge tube, originally it was used in transmission part
of Russia tank. It also was used in America radio broadcast. This
amplifier is working in class A2, positive volt bias in grid. Grid bias
is about approximated 0V, plate current is about 130mA.



The most diffucult thing in design this tube amp is the heat from 100W
filament of 833 tube is terrible, it effect to another tube and cause
the noise in high frequency.



Specification:

Response frequency: 10Hz ~ 100KHz -1db

Hum Level :0.7mV

THD: 1% 1W

Output transformer is special order made from ISO (TANGO), primary allow current 250mA.



Sound is very rich, open wide range and detail with high speed and very hot vocal.
Input volt can be chosen from 100,117,230V

Tubes not included. Contact if you need tubes