about making amplifier

[mehtadhaval]

Hello everyone!
I want to make a good but very easy and primary amplifier which can drive two 8 ohm speakers from condenser microphone.
Anyone please help.

[danielwritesbac]

One microphone, but two speakers. This makes a question.
Do you want stereo or mono?

How many watts would you like? and/or What is the efficiency rating (in db) on the speakers, and how loud do you want them?

An amplifier of your description can be made with a chipamp (amplifier for speakers) and a very sensitive preamp (amplifier for microphone). Its improbable to do that much gain with a solo power amp module, so there will be 2 pieces.

Do you want to purchase a kit with printed circuit boards or do you want to make your own with just a chip and bit of phenolic board (veroboard, or experimenter's board)?

[EWorkshop1708]

Condenser Microphone + LM386 set to gain of 200 should do for a quick mic amp. Just use 2 for 2 speakers.

Look of datasheet for LM386, to get gain of 200, put a 10uf cap between pins 1 and 8. Use a 10K ohm resistor from positive supply to mic, then a 1uf cap from there to amp chip.

[mehtadhaval]

Ok forget about two speakers!
I want to drive just one speaker and i want watts between 2 to 10 watts!
So please suggest me any link or any e book or something like that so that i can build it at my home.

[danielwritesbac]

Originally posted by mehtadhaval
Ok forget about two speakers!
I want to drive just one speaker and i want watts between 2 to 10 watts!
So please suggest me any link or any e book or something like that so that i can build it at my home.

Here is a link to LM386:
http://cache.national.com/ds/LM/LM386.pdf
See page 5.
The LM386N-4 (handles up to 18v) can produce about 1 watt all by itself.
So, you don't need an additional power amplifier if you just want an intercom.

If that's not enough power, here's a power amplifier to boost it.
This photo attached is lm1875.
http://www.national.com/ds/LM/LM1875.pdf
For that 10w power output, it can use a very cheap 24vct (12+12 center tap transformer).
To also run the LM386 microphone amplifier from the same supply, LM386N-4 will work perfectly well; however you could run the others safely from a 5v power regulator chip.
This combo can probably make a karaoke appliance.

EDIT: What is the application?