HiFiBerry Amp 2
From Autopilot Wiki
HiFiBerry Amp 2 | |
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Modality | |
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Manufacturer | |
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The HiFiBerry Amp 2 is an integrated amplifier and sound card capable of playing audio at 24 bits/192kHz. The Amp 2 is a HAT peripheral that mounts on top of the Raspberry Pi, uses the I2C protocol, and powers the Pi through its 5V rail.
Configuration
Note that the following is encapsulated in the autopilot script 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]:
dtparam=audio=on
And add the line:
dtoverlay=hifiberry-dacplus
ALSA
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
}
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!) |
Specs
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 |