how can i make a amplifer

This project is a bit challenging, I suggest using a disposable beverage cup with the bottom cut out.

why cardboard only even a thick sheet of paper is enough.

i want make an amplifier please teach me ================================= You want to know how they work? Or you want to build one from parts? Why not buy a kit? Lots of amplifier schematics... just find a simple one and hook up the parts like on the schematic.

Here is some advise to get you started:

Begin again in the discussion group for beginners, sci.electronics.basics (This one is for discussions between designers, and you aren't one yet, I suspect.)

Think about what you want to end up with (e.g. headphone amplifier, guitar amplifier, stereo speaker amplifier, microphone preamp, etc.) and tell us about that.

Are you more interested in learning about how amplifiers work, or in having a piece of equipment?

Try to give us some idea what you know and don't know, now, on the subject, so we know where to start.

On 02/12/2005 the venerable snipped-for-privacy@yahoo.com etched in runes:

Take a sheet of cardboard (a cereal box is good) and roll it into a cone shape. Cut off the small end and talk into it. Lots of noise will come out of the big end.

Hope this helps.

On 02/12/2005 the venerable snipped-for-privacy@gmail.com etched in runes:

Or even two such and a length of string. Hey we have a telephone!

On 02/12/2005 the venerable Fred Bartoli etched in runes:

I stand corrected. Would 'Audio Collimator' be closer to the mark?

=========================================

Your best course of action is to obtain a 1st-class engineering degree in electronics, within 14 days, from a reputable American college. All you have to do is supply details of your bank account so that the fee can be extracted. It's quite legal.

You will then be qualified to teach the subject and answer the many questions which appear on this hi-tech newsgroup.

For a small extra charge you can have a picture frame in which to hang an artistic, gold lettered certificate to proudly hang on the wall of your toilet.

Are you unable to detect an obvious leg pull?

"John B" a écrit dans le message de news:43906b81$0$5853$ snipped-for-privacy@master.news.zetnet.net...

This is not an amplifier but an impedance matching transformer :-)

(snip)

How obvious must I be before you figure out the answer?

Okay, you've had a lot of joke answers, but here's the real deal; how to make an amplifier in one simple sentence:

Get a bipolar transistor and apply dc voltages to it such that the emitter is grounded, the base is +0.6v and the collector is at half the stated voltage of your battery; inject your input via a capacitor to the base of the transistor and take your (amplified) output from the collector via another capacitor.

That's pretty much all you need to begin. You can then build on this simple one-stage amp and add extra components to improve its stability, distortion, efficiency and what-have-you. Then you can add more stages for more gain and finish up with a follower stage that will deliver useful power to a loudspeaker. Have fun.

If you tie the ends of the string together you'll have positive feedback which will dramatically increase the gain.

That doesn't amplify.

Indeed. But I suppose it has directional gain, like a beam antenna.

On 02/12/2005 the venerable John Popelish etched in runes:

. .

. .

The Unknown As we know, There are known knowns. There are things we know we know. We also know There are known unknowns. That is to say We know there are some things We do not know. But there are also unknown unknowns, The ones we don't know We don't know.

?D H Rumsfeld (poet), Feb. 12, 2002, Department of Defense news briefing