3 4 W power amplifier schematic

The schematic above is amplifier based on ic TA7211P or TA7212P , circuit above using OT transformer as a booster amplifier again. The amplifier suitable used on outside / field, because by using a transformer OT is identical to the PA amplifier.

Part List :

R  = 1K , 10R , 3K3

C  = 1uF , 10uF , 1n , 68u, 3u3, 2n2 x 2, 100u 

IC = TA 7211P / TA7212P

Technical information :

Max Vcc = 15 VDC

Min Vcc  = 4 VDC

Po            = 3,4 W

Rl            = 8 Ohm

Icco         = 16 mA

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3 Band Graphic Equalizer schematic diagram

This schematic schema diagram is very simple. Just need a single op amp IC LF351 (IC1) and few passive components.

The component values of this schema are not very critical and can be replaced with nearest values with a little loss on the performance. This feature make it easy to be assembled from your junk box.

The op-amp LF351 is wired to operate in three frequency ranges- high,medium and low. The schema is designed such that the schema produces +/-20 dB boost or attenuation for 50Hz,1KHz and 10Khz by varying POT’s R3, R6 and R9. The maximum amplification for any of these bands at maximum supply voltage is 20dB. The op-amp LF 351 is wired as an inverting amplifier whose response to frequencies 50Hz,1Khz and 10KHz can be varied by adjusting POT’s R3,R6 and R9.

Notes:

• The schema can be operated from 6 to 24 V DC .What I recommend is 12V .
• Use a 12V battery or 12 V DC power supply for the schema.
• All capacitors must be rated 15V.
• A 10uF/15V capacitor must be connected between +ve and -ve pins of LF351 if the power supply is far from the schema. Not shown in schema.

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