NE5532: Output wave distort when carrie the Load

1. schematic

2. No load, test between C6 pin1,2.

3. Carrie the load.

Hello,

The NE5532 is a audio signal amplifier capable of 600 ohm load. It does not perform well with 8 ohms or 33 + 8 ohms. NE5532 has a current limited output. 

Other note, 33+8 ohms and 10uF only goes down to 400Hz. 

Would you like a speaker driver IC recommendation?

Hello,

Is there any solution to solve the application with  33+8 ohms loads? could you help to explain the distort wave in the C6?

thank you!

HI Ron

Based on the current design, what can be adjusted to make the speaker volume higher

Hello Guo,

You can double the output current capability by using both channels. Minimum output "short" current is 10mA (that is 25C, hotter will lower this current).  Assuming a 4V loss on NE5532 output leaves 8V or +/-4V. 4V/20mA = 200 ohms. 

Therefore, add a impedance matching transformer (high impedance) to 8 ohms. Or pick a higher impedance speaker. 

https://www.digikey.com/en/products/detail/pui-audio-inc/AS015100MR-R/11618406

Add the two outputs like this. The speaker above (still an op amp overload at high output) will work much better than an 8 ohms speaker (major overload). Lastly don't put this into production, but OK for personal use. 

If you have to use 8 ohm speakers, How many can you put in series?

Hello Ron

only one 8 ohm speaker, the sound is very small，so, do  you have any other suggsetion

With just one 8 ohm speaker, use both amplifiers and combine them per the previous picture. Then see how loud it can go before distortion (clipping) becomes an issue.

hello ron 

Thanks for your help, we find the root cause. Customer's 5532 is the fist PA. They don't give us  secondary PA .