Creating cheap linear transformers with customized linear transformers, 6P14 Vacuum Tube amplifier
Keywords: use custom-resistant linear transformers to make cheap 6P14 parallel power release
First, make up
Figure 1 shows two 6p14 parallel single-end power discharge circuit diagrams, only one channel is drawn, and the other is exactly the same, and the output power is 7W × 2. Figure 2 is an output transformer for the sputum-type linear transformer employed by this unit.
Second, the material
1. Early production of red light 71-2 type 6 lamp tube radio, using the chassis one pay, 2 power transformers, 470KΩ volume potentiometers with power switch, 4 high and low tone potentiometers, 17 The bit wiring bracket is over, two 6N2 tubes.
2. Output transformers use Tianjin Wenhua Electric Appliance Factory in the 1970s to produce a 15W defragment linear transformer 2. The primary is 0 to 250Ω, the secondary is 1,0 to 8Ω, the transformer core quality is excellent. The original transformer silicon steel sheet is changed to all pairs, and the two-layer thickness of the two-layer thickness of 0.1mm is an air gap.
Third, assembly points
1. Transformer mounting: The power transformer left on the left end of the original chassis is retained, and the transformer on the right end is installed in the same direction. According to the principle of circuit induction, the output transformer is also installed. In addition, the power transformer is isolated from the electric transformer and the tube or the like by a piece of original galvanized iron (about 100 mm × 80 mm.
2. The tube positioning: 6 tubes are mounted at 6A2, 6k4, 6 N2, 6P1 and two medium-sized positions of the original machine, and the dual triode 6n2 can be used to use 6N1 or 6 N11, the three pins. 6N2 is a low frequency voltage amplifier, amplification factor 97.5.6N1 is a low frequency voltage amplifier, amplification factor 35, and R3 is changed to 100 kΩ when using this tube. 6N11 is a low noise voltage amplification, amplification factor 27, and R3 is changed to 100kΩ, the screen pressure is 45V, R9 is changed to 65kΩ, and the screen is 65V. These three tubes have a thousand autumn.
3. Grounding method: A little grounding method is used, and the ground is selected at the respective main filter capacity and the common solder joint of the respective main filter capacity and transformer on the left and right ends, and then welded to the original lead pads on the chassis as the total location.
4. Component positioning: strict testing must be conducted before all components. The left and right channel components of the terminal are half. The positioning of the component relies on the wiring rack, the potentiometer, the solder piece of the electro-tube core column. Each electron holder core solder piece is the grounding point of the tube and the component, and then the coarse wire is connected to the coolder, the access point is accessed. Shield line selection single core line. The shield line of the volume potentiometer is grounded, and the remaining shield lines are grounded, and the grounding points are introduced into their respective electronic tubes. The outer casing of the entire potentiometer is connected to the bottom plate. Capacitor C1 is a small volume CZMX-2 type, grounding its iron outer ring. Capacitor C10 is an LTT type, and its appearance is grounded with a white-aluminum foil shielded in the market.
5. High pressure delay: The resistance of adjusting the R26 can change the time of switching high pressure, when 270K, delayed 36 seconds.
Fourth, small knot
After the machine is assembled according to the above measure, the internal components look neatly symmetrical. Put a pair of 8Ω 10-inch speaker speakers, plug in the DVD machine, put the disc, turn on the power, but do not press the play button, will boost the volume, the tone potentiometer is all in the maximum position, the ear is close to the speaker, you can't hear a little communication .
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