class A amplifier

Say... what *is* your ultimate objective, by the way? If you want a good (reasonably efficient, relatively cheap, good sound quality, medium power) solution quickly, you may be happy with the LM3886.

Best wishes,

Michael

wholesale

to

gher

wholesale

e.

...

Just as long as they're large enough, and don't suffer from Capacitor Plague...

Thanks for the link to the LM3886.

What is my ultimate objective ? Mmmm, ... difficult question ! ;-)

For now, it is having fun. And for me (and for now) having fun is:

- to be able to build something real that I can touch and listen (I am building software all day long);

- to experiment with my children;

- to learn something;

- to mix theory and practice;

- to exchange ideas with people;

- listening music on something I have build and designed;

- writing some code to generate different audio waveforms at different frequencies. I will put them on cd for testing (I have a scope but no function generator);

- to sniff solder smoke;

- to burn my fingers with hot components (practice the Joule effect);

- ...

I am not interested in buying a new amplifier (I have already a Cyrus) Or perhaps a Nad C325BEE ...

Olivier

Ok, I will buy "normal" capacitors.

Olivier

A beautiful description. It's what drives me as well. If something is not enjoyable, then through choice it should not be pursued. I sometimes get the feeling that many professionals (of all callings!) are born with their boots on, (a local expression) hence never need to pass through a learning phase :).

I'd do it different, but basically it's right out of the book. Unless you have to adjust the bias periodically, I'd pick an operating point and use a fixed resistor for R3, then put the left side of C2 to the wiper of the volume control pot (in ampli1).

The preamp is pretty much standard; there's no problem with the volume control, depending on the signal level you're dealing with.

As I suggested above, move the volume control to the input side of the power amp, and run the preamp full-bore all the time - just design the circuit so that you get "line out" (about 1VRMS) for your maximum expected input.

And as far as C4 & R8 (preamp1), you're already ahead of me on that one. ;-)

Cheers! Rich

This is probably foolish; you'd be paying extra for the marketing bype.

In that application, just get the cheapest electrolytics they have.

Cheers! Rich

Graham, don't be a dork. The guy wants to _BUILD_ stuff! He needs to be encouraged - the "let's build it and see how it works" mentality is all too rare these days.

Thanks, Rich

I agree with it totally. To ecourage you to build s***ty circuits would be grossly negligent.

If you want to learn about audio amplifiers, some excellent resources can be found here ....

Graham

I have given him a link to a far far better site.

Graham

I agree with the principle but it seems he hasn't done his homework first. His present course of action is more likely to involve learning how to let the magic smoke out. So I have directed him here ....

Where he will find a wealth of first class info.

Graham

Well that's good but dare I say you missed out on the practical lab work ?

Take a look at this will you. He's another good amp designer too.

I hate to see people waste their time walking down blind alleys.

Graham

Graham,

What's your take on this low-TIM amplifier?

Michael

What about point 7 ?

primitive.

junk.

wholesale

I am not being aggresive. I'm teaching you some valuable facts.

That's called marketing. Nor is the Farnell catalgue a textbook, despite its other excellent uses. Do you think the CDs or whatever you listen to were produced on equipment using these stupid caps ? I can tell you for a fact because I design such equipment that there's not a hope in hell real designers take these audiophool pieces of junk seriously.

Graham

primitive.

junk.

No, I'll bet he's referring I expect to audiophool parts, and you of ALL people should berate him for that.

OTOH if the guy can't distinguish *capacitance value* from *quality* he shouldn't even have started.

You see, you don't understand this field. The audiophools promote crap circuits built with absurdly expensive components because they think the cost of the parts is what determines the result.

This is the kind of thinking that drives the pro-audio guys mad !

Graham

Apology please ?

I could smell it 100 miles off.

Graham

That's why I mentioned the 'crap' Asian caps.

Plain ordinary Panasonic electrolytics are just fine. Indeed they're one of my faves since they're moderately priced and have good general specs.

Graham