LME49710 based audio amplifier

[Anirvan]

HI everyone!

I came across an audio amplifier based on LME49710 Opamp. It's nice but I want to increase it's power to 10 watts to use it on any party in my home. Can anyone here help me how to increase it's power to 10 watts or so. I love making audio systems as I Love music just too much 🙂


I'm attaching the circuit I got from a magazine
Thanks in advance

 

[DPH]

Depending on your load impedance but 10 watts into 8 ohms is +/- 12.65V (at the speaker, so account for your losses). You could use a LME49860, which is a LME49720 qualified for 44V between its rails (rather than 36V). A small EF2 should get you there. Otherwise and less recommended, consider a higher output rail and use a small bit of gain in a CFP arrangement to increase your voltage swing.

 

[tomchr]

The LME49710 will swing to nearly rail-to-rail while providing a clean output. Allowing for the drop across the output stage, you might want to run the amp on 30-36 V. I'd use a regulated supply (there are some 36 V SMPS options available) to prevent over-voltage of the LME49710. I haven't analyzed the schematic in detail, but you should be able to just bump up the supply voltage without making changes to the design.

Tom

 

[DPH]

Nothing too fancy with relatively simple compensation on gain of ~5. The only thing I could see needing to be changed as you bump up to 30-36V is R2 and R3, which set the bias current.

I think everything else might stay put.

 

[rayma]

I came across an audio amplifier based on LME49710 Opamp.

This op amp is out of production and not available, do you have some?

 

[DPH]

^The 49710 is EOL, but the 49720 is not, so you ground out the second channel or figure out if you can stably parallel it for a bit of performance (albeit noise current doubles, so it'd better be a low source).

Or make sure you lay out a second channel on the same board. 🙂