10 watts of tube A single-ended amplifier

I used tube instead of the high-power guts to do single-ended Group A transistor amplifier, and achieved good results, circuit diagram below.

The circuit only two to enlarge. Before the class for a total of 6 N3 overcast to enlarge. 6N3 is the μ (35) to enlarge the gate smaller negative pressure, cathode bias to 300 Ω resistance, the appropriate point, the abolition of bypass electrolytic capacitors, forming the current level of negative feedback, feedback of medium. Final output of bile 6 N6 and high-power-of Transistor, 110 Ω resistance level feedback-based radio-resistance, so that the level of work, very stable, because the current negative feedback, driving ability, a constant current characteristics, non-line Distortion of the low. Gallstone compound in the maximum current output when the pressure drop of less than guts transistor, the transistor and Youdan flavor but also higher than the output efficiency of bile transistor.
The circuit is simple, dual-channel share the same power, the former class do not have to decoupling circuit, there is no stray coupling of concern. If the filter will be replaced by non-electrolytic capacitor quality electrolytic capacitor, the machine is a non-electrolytic capacitor amplifier. Also due to lower internal resistance of the output, greatly relax the demanding output transformers, the output transformer that is common to achieve outstanding results.

At the end of the collector-stone for the current 0.115 A, the power consumption of 25 watts, the output power of 10.3 watts. Reduce its cathode resistance resistance, the ER, output power can reach 15 to 20 watts, at this time to re-design output transformer. A amp heat sink must be large enough to facilitate cooling.

Stone High-Power Transistor reverse pressure is greater than 500 V, β value can not be too low. Tube 6 N3, 6N6 available big eight feet instead of 6 N8P. Power transformer T1 power of 160 watts; T2 power output transformer 10 watts, S = 9.6cm2, the initial diameter ∮ = 0.27 mm, turn around 2100, sub-diameter ∮ = 0.8 mm, around 140 turns. Than the initial resistance level for the 1.8 k Ω: 8Ω. The filter inductance L S = 8.2cm2, diameter ∮ = 0.35 mm, until around for. T2, inductance L core 0.22 mm gap to stay Magnetically-shielded saturation.