FET 12W Audio Power Amplifier

Power amplifier 12W/8Ù FET

   ���� ������ ��������� �� ����, ���� �� ���� ���� �������� ����. ��������� ��� ������������ ���� ����� ��������� (��5534), ��� ���� ��� ���������� �������� ������� �������, ������ ���������, ������� ������������ ��� ��� ���������� ����������� V-MOSFET ���� �����. ������ �� �������������� �� IC1, �� ������ ���� ���������� ��� �� ��������� ��� ���� ����������� ��� ������ ������, ����������� ����� �� ���������� � ���� ����������� ��� IC1 ��� ������� ��� ������������ ���, ������������� ������ ��� ������ ������. ��� stereo ���������� �� ������ �� ��������� ���

   A small power amplifier, but with very good quality of sound. It combines a completed very good quality (NE5534), that has the possibility of control of low loads, high speed, low distortion and two transistors of technology v-mosfet in the exit. It can be replaced IC1, with some other equivalent and we increase the supply in the stage of expense, always being careful is maintained the supply voltage of IC1, in the levels of his specifications, achieving increase of output power. For stereo operation will be supposed are made two units.

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Specifications
Output Power 12W in 8� (max)
Input sensivity 3.2V rms (max)
T.H.D 0.002% (1KHZ)
Frequency Response DC - 100 KHZ (-3dB)
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Part List
R1= 33Kohm R8-11= 10Kohm C7-8= 100uF 40V
R2= 6.8Kohm R9-10= 0.47ohm  2W D1-2= 18V 0.5W zener
R3= 22Kohm C1= 1nF 63V D3-4= 1N4148
R4= 100Kohm C2-5= 47uF 40V IC1= NE5534
R5-7= 1Kohm C3-4= 100nF 63V Q1= 2SK135
R6= 330ohm C6= 4.7pF ceramic Q2= 2SJ50

    ��� ���������� ��� ���� �� ����, ��� ������ ��� ����� ���� ��������� ��� ��������� ��� ������������� �� POWER VMOS FET ��� ������ [2SK134 or 2SK135] [2SJ49 or 2SJ50], ����� ��� , �� ��� ����� ���������� ��� ���������� ����� ��� ��� Toshiba ��� ����� ������ ������� �� ������� �����. ������� �� ��������������� �� �� [2SK1530 N-FET ���� ���� ��� 2SK135] ��� [2SJ201 P-FET ���� ���� ��� 2SJ50]. �� ��� ���������� ����� �� �������� ���� ��-3� ��� ��� TO-3 ,�������� �� ����������� ������ ����������� ��� ����� ������ ���������� ������������ . ���� �������� ��� �� ��� ������ ��� ������������, ��������� ��� �� ����� ��� ��������� ��� ���� ��� �� ����������. �� ��� ���������� ��� �� ��� ��������� ����� ��� �� �� ��������� �� ���� ��� ������� �� ������������� ��� �� �� ������������.

   A branding that I want to make, that is in effect for all the amplifiers that I publish and use the POWER VMOS FET of series [ 2SK134 or 2SK135 ] [ 2SJ49 or 2SJ50 ], they are that, more above transistor they are not produced more by the Toshiba and are enough difficult they are found henceforth. They can be replaced with [ 2SK1530 in the place of 2SK135 ] and [ 2SJ201 in the place of 2SJ50 ]. The new transistors are in plastic case ��-3� and no TO-3, bear in bigger supply of operation and have positive factor of temperature. This mean that with the increase of temperature, is increased and the current that is gone through from through the transistor. The new transistors him I have still not tryed and me it would interest to learn if somebody him used also with which results.

Sam Electronic Circuits 11/01