super basic ab amplifier?

[Sounduser]

Can some link me to a super basic ab amplifier circuit and parts list, that I can bread board to a speaker.

Nothing too complicated, just something I can play with.. maybe ten watts.

Thanks.

 

[franzm]

http://www.ti.com/lit/ds/symlink/lm1875.pdf

 

[Ian Finch]

If you like a bit more discrete circuitry, this one looks good and the specs are excellent for the simplicity. It should be easily do-able on matrix or strip board. BOM and construction notes included.

 

[manicjovica]

can not be more simple

google for tda7375 application

 

[JMFahey]

Oh, PLEASE!!!
Do NOT recommend anything from Red Circuits pages, the repository for the worst designs on the Net.

That amp, like most others there, is an unstable nightmare.

EDIT: LM1875 or TDA20xx is a great way to start.

Excellent sound, guaranteed to work, tons of designs using them all over the Net, what's not to like?

 

[Mooly]

Can some link me to a super basic ab amplifier circuit and parts list, that I can bread board to a speaker.

Nothing too complicated, just something I can play with.. maybe ten watts.

Thanks.

Can you tell us what voltage you have to work with and whether it needs to be a single rail (advised) or a dual rail design ?

 

[Ian Finch]

....Do NOT recommend anything from Red Circuits pages, the repository for the worst designs on the Net......

Really? A young friend built a pair of those with the bass boost feature disabled, some time back - still fine from the first power-up as far as I know.

However, as the OP is looking for something to play with, I get the sense that chipamp apps won't be what he wants.

 

[bimo]

I sim this schematic for my friend who want build this using SMD parts. I wait his implementation.

This is very simple amplifier, and I am sure it will work at first trying. You can change VAS transistor (Q4) to better one, example: 2SA1381.

The article is using Indonesia language here.

 

[franzm]

Two classical circuits:
Simple 60 Watt Power Amplifier
http://www.diyaudio.com/forums/solid-state/236256-retro-amp-50w-single-supply.html
Or http://sound.westhost.com/project12a.htm
Will need some downscaling for 10-15W.
If you want multiple feedback: http://elektrotanya.com/heathkit_ar-15_sch2.pdf/download.html

 

[Ranchu32]

Who wants to build a chipamp?!

Here is a simple design with a bare minimum parts that I have not yet tested but should work fine.

The 2SK3320 is a dual device surface mount package, available from a number of suppliers. But if you are bread boarding you will find it easier to work with TO92 packaged JFETs instead.

Add an input cap if your source has any DC.

 

[Bigun]

Nothing too complicated, just something I can play with.. maybe ten watts.

Something proven, something simple with all the information you need (hopefully) ...

DX amplifier (a generic topology that is very well established for a long time) Greg's Web Site

60-80W Power Amplifier

 

[Sounduser]

Wow, loads of replys.

I've using a pc power supply to play with at the moment.

So I was thing that was a good place to start? as they have -12 and + 12 volts.

 

[Mooly]

-/+ 12 volts is fine. Do you know the current capability of each of those rails ? (I was just wondering if the minus rail had much current delivery behind it)

 

[thimios]

Wow, loads of replys.

I've using a pc power supply to play with at the moment.

So I was thing that was a good place to start? as they have -12 and + 12 volts.

Unfortunately -12V is 0.5-1A only .

 

[Mooly]

Yes, I'm not so sure a PC supply is an ideal starting point either. Half an amp will actually get you quite a long way but how abuse proof is the supply. That would be my worry.

If its all you have then I would say OK, but make sure you fuse the outputs and accept its limitations.

 

[cbdb]

There's always D Selfs blameless. It's a typical 3 stage design thats relatively simple, reliable, good sounding, proven. It's scalable, it should still work at lower powers. And an entire book written about it. If your looking for an education, this would be the one to build.

 

[Elvee]

Here are a few more examples of very simple amps, based on Moto and Philips AN's.
The first one can operate from a single 12V supply.

 

[Bob Richards]

I wouldn't waste my time with a PC power supply. I built a poweramp with the TI 3886 IC, which gives 50watts rms into 8 ohms using a +/- 32 volt powersupply. The entire circuit probably has about 10 parts. Easy to build and great sound.

 

[Sounduser]

I really just want to play with the fundamental components inside an amplifier.

What kind of power supply has a good negative rail?

 

[wg_ski]

None of them, unless they were made to power an audio amplifier. A basic split rail power supply for a 10 watt amp can be made from a 25.2VCT 2 amp transformer, a bridge rectifier, and two 4700uf 25V caps. Buy all that surplus and you won't have $20 in it. And it will work to power either a small Blameless or an LM1875-based chip amp. Here's something I cooked up 20 years ago, for exaclty that power supply. Should be ok - it's been re-drawn from memory. Used it for years and years - it replaced one based on the old Philips design. Not the most basic thing you can build but it has everything you'd need and bulletproof... if the drivers and bias stack are thermally connected (epoxy all 3 TO-92's to a small piece of aluminum). That arrangement is easier to breadboard than the usual EF2 outputs where you need a common heatsink for the outputs, drivers, and bias stack.