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Topic: Better options than LM386N-4? (Read 271 times) previous topic - next topic

dmillsap06

I'm needing some recommendations on a better audio amplifier.  I have two 3-watt 8-ohm speakers that I'm using.  I believe I'm getting the best possible sound I can with this little guy but I need it to be a tad bit louder so it's noticeable when people interact with this puzzle.  Any recommendations?  Appreciate the feedback :)

DVDdoug

#1
Oct 13, 2018, 03:56 am Last Edit: Oct 13, 2018, 07:02 am by DVDdoug Reason: Bad math
There are lots of amplifier chips.   But, what voltage are you supplying to the LM386?

Power is calculated as Voltage x Current, or it can be calculated as V2/R.   So for example, with a 5V supply you can get 5V peak-to-peak which is about 1.75V RMS.    That's the theoretical maximum and there will be some voltage loss through the amplifier.

So if my calculations are correct, that's about 1/4W 0.8W into 4 Ohms or 1/8W 0.4W into 8 Ohms.    (But since won't get the full voltage, you'll get less than that.)

A bridge amplifier will put-out double the voltage (10V peak-to-peak from a 5V supply) and that can give you 4 times the wattage.

dmillsap06

Currently supplying 5V from Arduino.  Do you have a particular chip you'd recommend?

DVDdoug

#3
Oct 13, 2018, 07:38 am Last Edit: Oct 13, 2018, 07:39 am by DVDdoug
I was trying to tell you, the voltage is the limiting factor.   The power increases with the square of the voltage.    If you power the LM386 with 12V you should get more than 4 times the power.

A different chip might help a little but you can only get so-much power out of 5V.

dmillsap06

Got it, got it sorry. Alright so lets say I throw in 12V, for the LM386, do I just feed that straight into Vin on Pin 3?  I currently have a 1k Resistor in place with the 5Vin.

MarkT

I'm needing some recommendations on a better audio amplifier.  I have two 3-watt 8-ohm speakers that I'm using.  I believe I'm getting the best possible sound I can with this little guy but I need it to be a tad bit louder so it's noticeable when people interact with this puzzle.  Any recommendations?  Appreciate the feedback :)
These days go for a class D amp, with bridge mode, and for 5V the PAM8403 springs to mind.
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