need help to build a preamplifier

[martinisonline]

Hi.

I built a 100 + 100 W power amplifier with the characteristics:

- sensivity: 600mV
- frequency response: 10 - 35000Hz
- Distortion HD: 0.01%
- Intermodulation dist.: 0.02%
- signal/Noise: 83 dB

and now, I have to build a preamplifier for it, and i need some ideas, circuits, etc
The circuit must have a volume, balance, bass and treble adjust.
If you have a circuit with digital control(SPI, I²C,etc) better. I'm thinking control the volume, balance, bass and treble with an infrared remote control.

The sensivity(600mV) is the biggest or the lowest value that i can put in the input?

thanks.

 

[IanP]

Try this circuit:
**broken link removed**
For infrared control you can replace standard potentiometers with digital potentiometers .. of X9C103/4 or DS1803/4 series ..
Regards,
IanP

 

[zhi_yi]

please tell me what is the different between pre amp and power amplifier?

thank you

 

[martinisonline]

please tell me what is the different between pre amp and power amplifier?

thank you Smile

It's a circuit that connects to a input of a audio power amplifier to amplify a little the audio signal.
It's necessary when the power amplifier has an input sensivity very hight and the audio signal is low.

Normally it's on this stage that we can adjust the volume, bass, balance,etc

 

[zhi_yi]

is it that pre-amp stage is the stage that receive input signal from any tranducers for example from a microphone, and then in the pre-amp stage we can set the treble, bass, midrange, etc, and then we connect the modified signal to the audio power amplifier to amplify the audio signal, is it?

thank you

 

[orbb]

yes it is. The preamp should primarily be able to amplify the very weak signal of the transducer without introducing too much noise. Some preamps also include frequency equalization as in audio preamps like you mentioned.