Audio preamplifier with tone controls

The margin of sensitivity and an overload of audio preamplifier circuits are designed to cope with more modern music program sources such as CD players, tape recorders, iPod, computer output audio, tuner etc... Source select switch and input connectors do not appear, and their number and their arrangement are left to the manufacturer.

A margin overload audio preamplifier for pre amplifier volume control extremely high input was provided input.After a gain level converter impedance (T1) negative feedback type low Baxandall and treble EQ step was ajoutée.Comme some very low noise (5.6 times) win this phase must provide, phase characteristics implementiert.Diese two transistors with FET input circuits was also excellent THD numbers "their" 4V RMS output and an exit low impedance, needed to drive right Mini MosFet power amplifier, but can be used for other purposes.

Audio preamplifier The parts list:

R1 = 220 K 1/4W resistance
R2 = 100 K 1/4W resistance
R3 = 2 K 7 1/4W resistance
R4, R5 = 8 K 2 resistors 1/4W
R6 4 K = 7 1/4W resistance
R7, R8, R13 = 2 K 2 resistors 1/4W
R9 = 2 M 2 1/4W resistance
R10, R11 = 47 K 1/4W resistance
R12 33 K = 1/4W resistance
R14 = 470R 1/4W resistance
R15 10 K = 1/4W resistance
R16 3 K = 3 1/4W resistance (see notes)

= C1, C2, C9 470nF lo polyester capacitors
C3, C4 = 47nF lo polyester capacitors
C5, C6 = 6n8 lo polyester capacitors
C7 = 10µF lo electrolytic capacitors
C8, C10 = 22µF 25V electrolytic capacitors
C11 = 470µF 25V electrolytic capacitors (see notes)

Q1, Q3 BC550C input voltages 100mA low noise = gain high NPN transistor
Q2 = multifunctional N-channel FET 2N3819