A large number of capacitors use German Red Weimar, audio frequency tubes 2240 and 970 for signal amplification; imported original MJE15033 15032 for the drive stage; imported ON Semiconductor MJ15024 MJ15025 gold-sealed tubes for the power amplifier stage, 2 pairs of parallel output per channel
The working voltage range of this line is DC+/-30~60V, but the use of high voltage in the production of a class A machine means that the heat will be greater, so the recommended voltage is DC+/-40-50V, and it is recommended to separate the left and right channels. Power supply, the power of each channel of cattle is above 300W, left and right independent, of course, the transformer can be bigger and better)
Regarding the quiescent current, the quiescent current is directly related to the temperature. The larger the current, the higher the temperature. The quiescent current has been adjusted to about 200mA per piece before shipment, but because of the different heat sinks used, the temperature rise is also different. Therefore, the quiescent current may also be different from the value I adjusted. The quiescent current can be adjusted appropriately according to the actual situation, and it is better if the surface temperature of the tube does not exceed 60 degrees.
It is recommended to use an AC dual 30-40V ring-null transformer (above 300W) to supply power independently, and then use the rectifier power board.
Note: The power amplifier board is shipped with only the thermal bridge
A large enough heat sink must be added before power on
When shipped, the quiescent current is adjusted to about 200MA for each piece.
Product name: AM81 gold seal power amplifier board
Output power: 200W
Impedance: input 100K output: 4-8 ohms
Input voltage: DC +45V -0- -45V (positive and negative voltage can be selected in the range of 30-60V)
It is recommended to use more than 300W, dual 30-40V AC transformers
Accessories: Insulation sheet, installation rose, and input patch cord
Price: Finished board with two channels (2 pieces have been tested, with thermal bridge)
Class AB status has been adjusted at the time of delivery. To adjust Class A, please refer to the following picture for adjustment, but the heat sink must be large enough (one side needs to weigh more than 2KG, and the temperature of the heat sink should not exceed 60 after the adjustment is completed. Degree, the heat sink will be damaged if it is not big enough, it cannot be adjusted

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