Stereo preamplifier with bass boost

This preamp circuit was designed around from CD player, tuner, Tape Recorder, etc., offers 4 AC voltage gain at least sensitive power amplifiers to cope. Fi House modern devices often with small loudspeaker cabinets installed, the low frequency range rather sacrificed. This circuit includes a low amp to overcome this problem. You can use a variable resistance, Bass Boost 0 maximum value + 16 dB @ 30 Hz. If a fixed maximum necessary boost value variable resistance can be omitted and replaced by a switch.

The parts list:

Notes:

• Diagram shows left channel only, but R1, R2, R3 and C1, C2, C3, which are common to both channels.
• For stereo operation P1, P2 (SW1), R4, R5, R6, R7, R8, and C4, C5, C6, C7 should be doubled.
• Figures in parentheses indicate PIN for the right IC1 channel connections.
• A protocol for P2 type ensures a more linear regulators of bass boost.
• Need for a simple boost with launch of thumb out - process P2 shall be omitted and SW1 added, as shown in the diagram.
• Bipolar stereo operation must be an SW1 type.
• Please note that the SW1, increasing use is if the switch is open and turning off closing switch.

Source: stereo with bass boost preamplifier