HiFiBerry Amp2

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HiFiBerry Amp2
Modality Audio
Part Type Raspberry Pi HAT
Manufacturer HiFiBerry
Product ID/Part Number Amp2
Product Page https://www.hifiberry.com/shop/boards/hifiberry-amp2/
External Datasheet https://www.hifiberry.com/docs/data-sheets/datasheet-amp2/
Price (USD) 49.90
HiFiBerry Amp2
Uses Interface(s) I2C
HiFiBerry Amp2
Uses (Board-Numbered) GPIO Pin(s) 3, 5, 12, 35, 38, 40, 7
Provides Backpower Yes
Computer Card Type DAC

The HiFiBerry Amp 2 is an integrated Amplifier and Sound Card HAT for the Raspberry Pi capable of playing audio at 24 bits/192kHz.

The Amplifier chip used is TAS5756M

Output Filtering

WARNING: while the part is rated up to 192kHz, there seems to be a low-pass filter applied to the amplifier to filter above 20kHz, see here: https://support.hifiberry.com/hc/en-us/community/posts/360014295118-Ultrasonic-frequency-response?mobile_site=true

Efforts to bypass the filter are ongoing. It should be possible to reconfigure the filter if it is a DSP filter, or remove the components if it is a hardware filter. According to the datasheet ( Tas5756m.pdf , page 60) the amplifier is commonly used with a passive LC lowpass filter.

Looking at the board, it seems as if the large black components next to the speaker output are the inductors, and the capacitors on either side are the other components in the filter. The datasheet discusses a filterless mode, so it should be possible to bypass the filter by removing those components and shorting the pads on either side of the inductor.


Note that the following is encapsulated in the autopilot script Scripts:hifiberry, which can be executed with

python -m autopilot.setup.run_script hifiberry

Device Tree

In /boot/config.txt, remove or comment out the following to disable the built-in audio[1]:


And add the line:



Optionally, you can make the card the default sound-card for ALSA by creating a /etc/asound.conf file with the following

pcm.!default {
  type hw card 0
ctl.!default {
  type hw card 0


See Troubleshooting Sound

Most common:

  • Check you're not using any of the reserved pins
  • Make sure that pin 7 is in your PULLUPS pref
  • Check that your OUTCHANNELS pref is set to the correct channel that you are outputting to
  • Ensure that the AUDIOSERVER is set to true

GPIO Usage

The following pins are reserved and can't be used for other purposes[2]:

Board Pins BCM # Use
3, 5 2, 3 I2C Configuration
12, 35, 38, 40 18-21 Sound interface
7 4 Mute -- pulling low mutes (so pull it up!)


Recommend powering with an 18V power supply!

Recommended operating voltage 12-20V
Absolute maximum operating voltage 24V
Maximum output power 60W
THD+N <0.02% typical, output power 0.1-10W
SNR 104db typical
Frequency response 20-20000Hz output filter characteristics depending on specific speaker parameters
Typical output power per channel 14W Vsupply=12V, Rspk = 4Ohm, THD+N <0.1%
18W Vsupply=18V, Rspk = 4Ohm, THD+N <0.1%
20W Vsupply=24V, Rspk = 4Ohm, THD+N <0.1%
8W Vsupply=12V, Rspk = 8Ohm, THD+N <0.1%
17W Vsupply=18V, Rspk = 8Ohm, THD+N <0.1%
28W Vsupply=24V, Rspk = 8Ohm, THD+N <0.1%
Maximum output power per channel 15W Vsupply=12V, Rspk = 4Ohm, THD+N <10%
30W Vsupply=18V, Rspk = 4Ohm, THD+N <10%
44W Vsupply=24V, Rspk = 4Ohm, THD+N <10%
10W Vsupply=12V, Rspk = 8Ohm, THD+N <10%
20W Vsupply=18V, Rspk = 8Ohm, THD+N <10%
38W Vsupply=24V, Rspk = 8Ohm, THD+N <10%
Sample rates 44.1-192kHz

Special:Contributors/HiFiBerry Amp2