mic-pre + power amp (NOT audiophile)

[neededandwanted]

If not the impossible, I am likely asking for the implausible, or at least the uncommon.

I need an amplifier that will take a microphone input and drive a modest loudspeaker.

Preferred microphone is the Panasonic WM-61A:
http://parts.digikey.com/1/parts/853...ni-wm-61a.html

I would like about 5W into an 8 Ohm load for the output, but will consider anything with at least 100mW.

A separate preamp and power amp stage is a possibility. A single chip amp would be perfect (if I could get that much gain in one stage). Even a driver chip with external MOSFETs may be OK.

It needs to be SUPER low cost, because I will need to build a ton of them (on NO budget).

Shared parts, especially shared power supply may simplify and reduce cost. (for example a chip amp with 4 channels of amplification on a single chip)

Mic level IN, speaker level OUT. 24-48 channels of this. (the signals all need to be discreet/isolated though)

What would one even call an amplifier that went from Mic level to speaker level? (other than "two amplifiers")

30-something years ago, I built these from a single transistor (called a GE-3 back then) and maybe only 3 other non-semiconductor components (for each channel) and ran them off of a car battery.

Really looking for cheap and simple. Limited bandwidth is OK. Inefficient is OK. 2% THD is OK (but seriously against my religion - ouch!).

Any ideas on where I can start looking?

[star882]

MAX4364. Only $0.45 per channel for the chips and only requires 3 capacitors and two resistors to operate.

[neededandwanted]

Originally posted by star882
MAX4364. Only $0.45 per channel for the chips and only requires 3 capacitors and two resistors to operate.

Thanks! That looks good - and cheap - and simple (low component count) solution.

Is there something special about this amp that makes it particularly suited to using and very low level input (microphone level, as opposed to line level) ?

Do you happen to know if there is anything similar that would have a bit more output power?

(by cheap, I certainly don't mean that we have to stay under $1 per channel necessarily...)