HiFiBerry AMP 2

An amplified HiFi sound board for Raspberry-Pi

The HiFiBerry Amp2 is a high-quality and highly efficient Class-D power amplifier for the Raspberry Pi. The board is plugged directly on the 40 pin GPIO connector of the Raspberry-Pi. Mounted onto the Raspberry Pi, the HiFiBerry Amp 2 creates a powerful stereo audio system.

The speakers are connected directly on the Amp board. Amp 2 is an ideal module for:

• multi-room audio installations
• small and elegant music playback devices
• home automation audio systems
• solutions that require high-quality sound but unobtrusive appearance

Features

• Up to 60W output power
• Capable of driving a pair of 4-8 Ohm speakers
• Fully controllable from the Raspberry Pi
• sample rates up to 192kHz
• Digital-analog conversion included, no need for external DACs or sound cards
• Digital sound transmission for optimal audio performance
• Connects directly to the Raspberry Pi A+/B+/2B/3B/Zero, no additional cables needed
• Only one 12-24V external power supply needed for both AMP2 and the Raspberry Pi, no need for USB power supply anymore
• No soldering required, the AMP2 is directly mounted on the Raspberry Pi A+/B+/2B/3B in less than a minute.

Ouput Power

The output power that you can expect from the AMP 2 depends on various criteria and also from your audio quality expectation.

• Higher is the input voltage and higher is the output power per channel.
• For a same input voltage: a 4 Ohms speaker will develop more power than a 8 Ohms speaker.

As former conclusion: using a 24V power supply with 4 Ohms speaker will develop the highests output power par channel. You can also use a 19V PSU for laptop.

The expected audio quality is also very important! For a same speaker (say 4 Ohms) and same input voltage (say 18V) you can expect 2 distincts output power. Either 18W or either 30W par channel. The difference between them is the audio quality (sound distortion). At 18W you will have a THD+N < 0.1%, so a very high quality sound. When pushing the volume, you can reach the max. output power (30w per channel). However, at such a power, audiophile will notice a sound quality decrease (the will increase to THD+N < 10%)  

Output Power per channel

• Vsupply=12V, Rspk = 4Ohm, THD+N < 0.1% -> 14W
• Vsupply=18V, Rspk = 4Ohm, THD+N < 0.1% -> 18W
• Vsupply=24V, Rspk = 4Ohm, THD+N < 0.1% -> 20W
• Vsupply=12V, Rspk = 8Ohm, THD+N < 0.1% -> 8W
• Vsupply=18V, Rspk = 8Ohm, THD+N < 0.1% -> 17W
• Vsupply=24V, Rspk = 8Ohm, THD+N < 0.1% -> 28W

Maximum Output Power per channel

• Vsupply=12V, Rspk = 4Ohm, THD+N < 10% -> 15W
• Vsupply=18V, Rspk = 4Ohm, THD+N < 10% -> 30W
• Vsupply=24V, Rspk = 4Ohm, THD+N < 10% -> 44W
• Vsupply=12V, Rspk = 8Ohm, THD+N < 10% -> 10W
• Vsupply=18V, Rspk = 8Ohm, THD+N < 10% -> 20W
• Vsupply=24V, Rspk = 8Ohm, THD+N < 10% -> 38W