8W+8W tube power amplifier

The preamplifier VE1 of this unit uses a low-muscle, low-R dual triode 6N6 (
half of which is used for the left and right channels). The working status is designed in Category A. The push stage VE2 uses the high-end, low-R domestically produced electronic tube EN11J.
The circuit form is the consensus low-distortion, wide-range SRPP (Shunt Regulated Push) circuit. 6 The final power amplifier VE3 uses the anode power supply of
    the tube directly taken from AC 220V. Municipal power grid. After the mains power is bridge rectified by VD3 ~ VD6 and filtered by C 6 C7, the +270v voltage t is obtained to supply power
to the screen electrode and curtain grid of the power tube 6P3P ; the +270V cross passes through VT VD11. VDZ adjusts and stabilizes the voltage to generate +250V power supply to feed the anode of the front stage VE1; +2sov is then filtered twice by R 7 and c 5 to form a +200v voltage to power the SRPP circuit. This direct power supply method can simplify the power transformer TP and is very beneficial to reducing the size, weight and production cost of the TP     . Since single-ended amplifiers have no CMRR (common mode rejection) effect, they have strict requirements on the power supply. therefore. The anode power supply adopts double capacitor filtering; in addition, all filaments are powered by current. Among them, the front and pusher are regulated by IC (VA78H06) and fed back to filament A; the other set of AC 12V, 2A winding is rectified by bridge VD¨~VD14 , C14 ~ C16 filter, generate about 1 2.4V voltage at the X, Y terminals for the dual-channel power amplifier tube filament power supply port power transformer TP, select "Sounda" finished product (5; OVA ~ 12VX 21220V)