Suggestions for low/medium power audio amplifier ICS?

[David Hess]

If so, 50W RMS for a "desk" amplifier? That'd be crazy anyway. You certainly don't need that. 10W RMS or below would already be enough to make your ears bleed in loudspeakers 1m away or so.

Bookshelf and smaller speakers can be pretty inefficient in the quest to get a flat frequency response so 50 watts is not that outlandish.

[tooki]

Uhhhh… even with that, 50W is a ton of power. For context, for typical desktop PC speaker use, 3W is enough. 10W is usually enough to annoy the neighbors.

[SilverSolder]

Yeah, I doubt I get over 1W on the desk.   In the car, on the other hand... 

[Gyro]

LM3886 or LM4776 if you want a good quality class AB chip amp.

Yes, they're supposed to be pretty good quality. You don't have to use the full 50W capability, just use lower supply rails and reduce the heatsinking requirements.

[2N3055]

LM3886 amps sound really good and it is easy to make them. You can power them with just a toroid transformer, diode bridge with filter caps and two elco capacitors..
Only thing is that you will need to heatsink them properly.
Some of the new class D amps sound surprisingly good too (Ti for example)  and practically need no special thermal considerations...

[mawyatt]

Agree, the LM3866 is a really good option. Might make a good Hi Power AWG Amp

Best

[tooki]

Are you guys deliberately ignoring what the OP said? They said a low/medium power amp with either a 5V or 12V supply.

A 315W amp that requires 18-53V? Not even close. A 68W amp that requires bipolar ±28V? Not even close.

OP, again, take a look at the TPA311x series, which will work on 5V or 12V and still have ample power.

[2N3055]

Are you guys deliberately ignoring what the OP said? They said a low/medium power amp with either a 5V or 12V supply.

A 315W amp that requires 18-53V? Not even close. A 68W amp that requires bipolar ±28V? Not even close.

OP, again, take a look at the TPA311x series, which will work on 5V or 12V and still have ample power.

Well in our defense, discussion was kind of of hijacked along the way...
But you have the point.

I think a device of the likes of the Fosi Audio BL10C would be more than enough to fit the bill and more...

[mawyatt]

Guilty as charged

Best,

[SilverSolder]

The simplest solution is to use an amp that someone else has already made!  -  I own 3 of these ones, and they perform very well for computer monitors, bedroom music,  portable sound, that kind of thing.

They are based on the Tripath Class D chip.   I wouldn't trust them to give more than about 5W-10W per channel of clean output, but if they are kept under that level, they actually sound good.  (Look at the specs:  12V, 3A power supply, but 2x20W rms.   Hmmmm....       )   -  but if you ignore the silly spec and just treat it as a 5 - 10W amp, you will be happy.

[cdev]

This info looks like what I need. Actually my wife was kind enough to lend me her amp and speakers because she as I said never uses them because she uses headphones all the time and also is super busy. But I think Imay still get an amp or build one from some of the parts I have if that is sufficient for my needs, to make an unltrasonic cleaner. (a different thread)

Might as well get things that are as flexible as possible.

Try a module based on the TPA3126d2 (or its older version the TPA3116), the slightly less powerful TPA3128 (or older TP3118), and or another in the TPA31xx series (there are numerous models, with the ‘26, ‘28, and ‘56 being the most powerful IIRC).

The TPA3255 is currently the best. Considering a board with it is available for as little as $30, there's not too much reason to go for something lower.

The TPA3255 is far more powerful than the OP asked for, and requires a minimum supply voltage higher than what the OP said they have available. The TPA31xx series works within the OP’s requirements.

[tooki]

The simplest solution is to use an amp that someone else has already made!  -  I own 3 of these ones, and they perform very well for computer monitors, bedroom music,  portable sound, that kind of thing.

They are based on the Tripath Class D chip.   I wouldn't trust them to give more than about 5W-10W per channel of clean output, but if they are kept under that level, they actually sound good.  (Look at the specs:  12V, 3A power supply, but 2x20W rms.   Hmmmm....       )   -  but if you ignore the silly spec and just treat it as a 5 - 10W amp, you will be happy.

Nice! That’s based on a chip in the series I suggested, and should do a fine job.

[cdev]

This is a really decent amp for its price and most importantly, when there is no signal going into it, its very quiet!''

this is a pet peeve of mine. As Ive often described here, I live in a semi urban suburban area with lots of RF noise so its actually quite surprising to me that I lucked out and dont have lots of noise.

Usualy when some gain device is hooked up here its all over the place. For example mu UNi-TUT61 DMM when I just put it on its regular V volts and hold the two leads apart would lead one to believe I was surrounded by "free energy tothe point that I could power various misc devices off of it!

The reading never holds still and it goes quite high sometimes from one moment to the next!

If I was obsessive-compulsive about things, I could see myself "having a field day" with all that electricity.

This amp sounds tight and strong, like live performance, with the dayton audio b652s. Its makes a kick ass computer system.

[SilverSolder]

This is a really decent amp for its price and most importantly, when there is no signal going into it, its very quiet!''

this is a pet peeve of mine. As Ive often described here, I live in a semi urban suburban area with lots of RF noise so its actually quite surprising to me that I lucked out and dont have lots of noise.

Usualy when some gain device is hooked up here its all over the place. For example mu UNi-TUT61 DMM when I just put it on its regular V volts and hold the two leads apart would lead one to believe I was surrounded by "free energy tothe point that I could power various misc devices off of it!

The reading never holds still and it goes quite high sometimes from one moment to the next!

If I was obsessive-compulsive about things, I could see myself "having a field day" with all that electricity.

If you connect an amp to a computer, it can sometimes be difficult to keep the background noise under control due to ground loops between different devices plugged into the PC.  In my case, I had issues with a printer plugged in via USB...   as soon as the printer was plugged in, there was a background whine!  I ended up using a small audio isolation transformer in the audio lead, which made it all nicely quiet again.

[MarkF]

The simplest solution is to use an amp that someone else has already made!  -  I own 3 of these ones, and they perform very well for computer monitors, bedroom music,  portable sound, that kind of thing.

They are based on the Tripath Class D chip.   I wouldn't trust them to give more than about 5W-10W per channel of clean output, but if they are kept under that level, they actually sound good.  (Look at the specs:  12V, 3A power supply, but 2x20W rms.   Hmmmm....       )   -  but if you ignore the silly spec and just treat it as a 5 - 10W amp, you will be happy.

Nice! That’s based on a chip in the series I suggested, and should do a fine job.

F.Y.I.
The Fosi BT20A is based on the TPA3116 chip.

[David Hess]

Uhhhh… even with that, 50W is a ton of power. For context, for typical desktop PC speaker use, 3W is enough. 10W is usually enough to annoy the neighbors.

I agree, but we are talking about bookshelf speakers and not typical PC speakers.  Bookshelf speakers will be 2-way or 3-way with a built in passive crossover, and are often ported like mine are.  In order to get flat and extended low frequency response in a small enclosure, they have to sacrifice efficiency, so higher power is required to get the same sound pressure level.  My previous "high end" powered PC speakers were toys in comparison; I only used them because they were free and I had no need for anything better.

The specifications of the mentioned BT20A (and BT30D that I have) say that they operate down to 12 volts, at reduced output power of course.  But I think FOSI is specifying peak power as twice RMS power so halve the power levels they advertise.  The TPA3116 datasheet from Texas Instruments gives a much better idea of available output power.

Taking into account the above, my BT30D is a more reasonable 15 watts into 8 ohms.

If you connect an amp to a computer, it can sometimes be difficult to keep the background noise under control due to ground loops between different devices plugged into the PC.  In my case, I had issues with a printer plugged in via USB...   as soon as the printer was plugged in, there was a background whine!  I ended up using a small audio isolation transformer in the audio lead, which made it all nicely quiet again.

Ground loops can be a major problem if you do not plan ahead.  It helps a lot to make sure that all of the components are plugged into the same outlet strip.

I could not hear any noise from my BT30D with a direct analog connection, so ended up not buying an optical DAC, but I was prepared to if there was an issue.

[tooki]

Uhhhh… even with that, 50W is a ton of power. For context, for typical desktop PC speaker use, 3W is enough. 10W is usually enough to annoy the neighbors.

I agree, but we are talking about bookshelf speakers and not typical PC speakers.  Bookshelf speakers will be 2-way or 3-way with a built in passive crossover, and are often ported like mine are.  In order to get flat and extended low frequency response in a small enclosure, they have to sacrifice efficiency, so higher power is required to get the same sound pressure level.  My previous "high end" powered PC speakers were toys in comparison; I only used them because they were free and I had no need for anything better.

My numbers are from actual measurements using 2-way and 3-way bookshelf speakers.

[SilverSolder]

Pretty much any speaker should hit 85dB at 1 meter, at 1W?  Many will do better than that.

I guess it all comes down to what we consider normal listening levels - and whether you want the neighbours to be listening as well!   

[2N3055]

Pretty much any speaker should hit 85dB at 1 meter, at 1W?  Many will do better than that.

I guess it all comes down to what we consider normal listening levels - and whether you want the neighbours to be listening as well!   

That is a single one. A pair will be 3dB louder...

[cdev]

Proper listening level is when it pumps your body in the solar plexus,,it gets you right there in trhe center of your chest.
moves your ass  Google translates that as eMueve tu culo

[SilverSolder]

Proper listening level is when it pumps your body in the solar plexus,,it gets you right there in trhe center of your chest.
moves your ass  Google translates that as eMueve tu culo

In my car, I have a system that meets that specification.   On the desk, though...   

[David Hess]

Proper listening level is when it pumps your body in the solar plexus,,it gets you right there in trhe center of your chest.
moves your ass  Google translates that as eMueve tu culo

With the properly tuned 6-1/2 inch subwoofer that I built and tuned, I can rattle the windows without being able to hear it.