audio amp question

[Dan Stephen]

I have a client who is looking for the following:

a 9 volt audio amplifier into which a microphone and headphones plug.

The purpose is for him to be able to speak to a man who is extremely hard of
hearing.

Any ideas for a cheap circuit?

Dan

 

[Graham Knott]

Dan Stephen wrote:

I have a client who is looking for the following:

a 9 volt audio amplifier into which a microphone and headphones plug.

The purpose is for him to be able to speak to a man who is extremely
hard of hearing.

Any ideas for a cheap circuit?

Dan

--
Have a look at
http://homepage.ntlworld.com/g.knott/elect24.htm

 

[Roman Arnet]

Dan Stephen schrieb:

I have a client who is looking for the following:

a 9 volt audio amplifier into which a microphone and headphones plug.

The purpose is for him to be able to speak to a man who is extremely hard of
hearing.

Any ideas for a cheap circuit?

Dan


I he going to blow up his ears?!

Roman

 

[Dan Whelan]

Ok, seriously, I suggest staying away from building a hearing aid.
It's not about one's skill level...it's more about who's going to be
the one blamed if something were to go wrong. It doesn't matter if
your circuit is the cause.

That being said.....

Williams Sound has made some products called "assistive listening
devices"
http://www.williamssound.com/

I'm not sure how willing they would be to part with their schematics,
but there you have it.

Other than that, if you're still interested in making the device...

You can combine a mic pre-amp with a generic op-amp amplifier circuit
for headphones to accomplish the same thing. A good source for
schematics is www.discovercircuits.com

Dan


"Dan Stephen" <danno@dodo.com.au> wrote in message news:<4156a887@news.comindico.com.au>...

I have a client who is looking for the following:

a 9 volt audio amplifier into which a microphone and headphones plug.

The purpose is for him to be able to speak to a man who is extremely hard of
hearing.

Any ideas for a cheap circuit?

Dan