Need help choosing an amp for 3.6

[Jubalrahl]

I want to use the DAC pin on the teensy 3.6 and could use advice on which amp to use and how to set it up. I can't find any examples that don't use the audio board, so I am a bit lost. Any info would be helpful and appreciated.

 

[KurtE]

It may depend on what all you need/want. The easiest is the propshield, although you have to take care of the DAC pin is in different location.

On some of my boards, which are only for my own usage, I use a: LM4862M chip.

Circuit looks like:


I use a small speaker on my boards, which don't give me a lot of sound, but enough for some feedback information:

 

[oddson]

I want to use the DAC pin on the teensy 3.6 and could use advice on which amp to use and how to set it up. I can't find any examples that don't use the audio board, so I am a bit lost. Any info would be helpful and appreciated.

What does it connect to?

 

[Jubalrahl]

The amp is supposed to connect to a small 8 ohm speaker. I want it to be loud enough for someone a few feet away to hear a letter clearly. Not meant for music. It is part of a senior project. We are upgrading from an arduino micro to a teensy 3.6 because of the bigger memory and speed, so we may as use the sd card reader and DAC instead of the separate sd card reader that doesn't have an amp.

 

[oddson]

LM386 is widely used for applications like that.

https://www.arduino.cc/en/Tutorial/SimpleAudioPlayer

Edit... I see the chip Kurt is suggesting is on the prop shield. You could just copy the bottom part of that schematic. Maybe with SD input to pulled to ground instead of to a uC pin.

 

[PaulStoffregen]

I can't find any examples that don't use the audio board, so I am a bit lost. Any info would be helpful and appreciated.

This project used the DAC pin and prop shield amp.

https://github.com/PaulStoffregen/TouchGuitar

 

[nemation]

LM386 seems to be a good choice. Though, if space is a critical factor, there could be the need for a smaller package. I made some tests recently and came up with a LM4875MM.
(using the DAC on a custom Teensy 3.2)

 

[Jubalrahl]

Thanks for the ideas guys. Looking at the schematics you've shown me and what I've read about making an amp circuit the passed few weeks I see how important capacitors are. I read how even using a full audio board from Adafruit with their amp could have noise issues if they are powered from the same source, but don't have capacitors to filter out the noise. I will be sure to include them in my design.