Amp education

[TexasFight]

Greetings forum. I landed here after watching many Dave vids.

I want to get more info on Amps. Are op Amps the main or only amp? Searching "amps" populates to many non electrical information. Are amps used for sound equipment an op amp? I want to by some amps and tinker but would like additional info. Op amp, inverted and non inverted are all I know of.

Thanks
   

[retrolefty]

Amplifier is a kind of generic name in electronics for any circuit that increases either voltage and/or current from it's signal input to it's output terminal. Also amplification can cover any frequency not just audio.
 
I would recommend you do more research so you can better target your goals and interests before buying too much stuff. Good luck.   

 

[TexasFight]

Yea. Good Point.

I guess an additional question would be - what amp(s) are good to begin tinker education. LM741? I have some LM386's on the way. Any that are most common?

[CD4007UB]

To introduce students to op amps, we use the TL081 - a general-purpose op amp with a JFET input (which produces very high input impedance and very low bias current). It's cheap and also still available (just about) in through-hole dual-in-line packages. (If you need to use multiple op amps, the TL082 and TL084 contain 2 and 4 op amps, respectively.)

Note that the TL081 (like the 741) uses a dual-rail power supply (usually +/- 15V). Some modern op amps (especially those for use with microcontrollers) use a single supply rail.

[TimNJ]

An amplifier is any device or circuit which (basically) applies a multiplication operation to an input signal. For instance, the signal produced from a microphone is weak and tiny. It alone cannot drive the massive loudspeakers you might see (and hear) at a concert. So an amplifier basically makes an exact copy of that signal but much larger in amplitude. This strong signal (with large amplitude and from a low impedance source) is able to drive the speakers.

An op-amp cannot power a large speaker, but it might be used to amplify the signal from the microphone. Op-amps are low-distortion, low-noise, and have high input impedance which are all things you'd want in a microphone pre-amp. An op-amp might be used to cleanly boost a signal so that a high power amplifier can deal with the signal effectively. The high power amplifier might be a transistor amplifier (see: common emitter or common source amplifier). Oh and by the way, vacuum tubes were used before all of this op-amp and transistor stuff.

The audio example is just one of many. Wireless transmission relies on amplifiers to create a high power radio frequency (RF) signals. You might use an op-amp (or more specifically, an 'instrumentation amp') to detect tiny electrical signals produced by the human body. (think: ECG/EEG)

Hope this helps.

[george.b]

There are many kinds of amplifiers. Operational amplifiers are but one of them.
You could probably benefit from reading a textbook on the matter. "The Art of Electronics" has chapters about amplifiers, operational and otherwise.

An op-amp cannot power a large speaker,

Most can't, but those like the OPA549 beg to differ

[TimNJ]

There are many kinds of amplifiers. Operational amplifiers are but one of them.
You could probably benefit from reading a textbook on the matter. "The Art of Electronics" has chapters about amplifiers, operational and otherwise.

An op-amp cannot power a large speaker,

Most can't, but those like the OPA549 beg to differ

Okay true but 99.999% of op-amps in use are NOT power op amps. Just to keep things simple here.

Not to self promote but here’s a video I did on op-amps. Beginning is a little repetitive and dry but people have said it was helpful.

https://youtu.be/gzb5Bw3Wusc

[Shock]

If you don't know what resistors capacitors and transistors are and how they can be combined in order to create a basic single transistor audio amplifier I suggest starting there.

[rstofer]

Not to self promote but here’s a video I did on op-amps. Beginning is a little repetitive and dry but people have said it was helpful.

The video is long but thorough and there is a full disclosure right up front that it isn't the usual 10 minute 'quickie'.  Now I imagine I will need to go back to the earlier videos.

My interest in op amps is pretty much focused on analog computing and the vehicle suspension model was great!  Now that I have an AWG, I suppose I'll have to convert my mass-spring-damper program to include x(t).

[b_force]

amp is short for amplifier (and sometimes people use it for current as well).
I guess you know the word 'to amplify"?
(to make larger, greater, or stronger; enlarge; extend. Or increase amplitude)

That's exactly what it does, and like people said before there are different ways to amplify.
You can amplify voltages and currents, hack you can even 'amplify' other things.
How it's being used depends on the specs of the amplifier. How much current and voltage it can deliver.

Words like 'power' amplifier or 'audio' amplifier are all relative.
It's focused on its main intention, but doesn't always mean it's limited to it.
When you use what all depends on the application and which compromises you have to make.