High power tube power amplifier 02

Now we recommend two high-power tube power amplifiers with superior performance and easy production. (
    1) Voltage amplifier stage
    The circuit principle of this machine is shown in Figure 1-39. Its voltage amplifier tube Vl can be 6N9P. 6N 8P 6N1 , 6N2 and other double
transistors, the input impedance is above 200kn, and the dynamic range is large. The input signal is first amplified by capacitive coupling, and then
inverted by the Tl inter-stage transformer. The transformer turns ratio is 1:1, and Ffi parallel feed is used. Electrically, the two
470k0 resistors connected to the secondary side of the inter-stage transformer serve as grid bias resistors for the push tubes V2 and V3. It also plays a role in stabilizing the work of the amplifier. Review
    (2) Push amplification stage
    The push amplification stage of this machine adopts push-pull mode to ensure excellent amplification characteristics. The push tube VE2.VE3 can be
changed to 2A3, 6C4. 6N7P or 6P1, 6P6P. The transistor connection mother T2 is the input transformer. In order to suppress the amplification and reduce
the distortion, the ratio of the number of transformer coils is still 1; ld
    (3) The power amplifier
    stage uses a Class A and B amplifier to obtain higher fidelity. , the power amplifier tube can use 845. 211. 811, 812
, etc. T3 is the output transformer, the optimal load impedance from the primary to the screen is 69000, and the screen pole voltage is iooov.
The secondary low-impedance output of the output transformer is 8fl and 16fl, which can be directly connected to high-fidelity speakers; the high-impedance 250fl output block is equipped with Wiring room transformers are designed
for long distance transmission. If the
    power amplifier tube
is switched to 805 (FU-5), the screen electrode voltage increases by 1200V to 1500V, and an output power of more than 200W can be obtained.