This is a review and detailed measurements of the HifiBerry AMP60 made for RPi form factor. It costs US $44.90 and was kindly dropped shipped to me by a member.
While the unit looks like a typical RPi "HAT," it is actually a stand-alone amplifier with no dependency on the RPi computer. It does however have headers for input which mate with company's own DAC (output). For testing, I just wired up a set of RCA cables to the header.
You are responsible for supplying a power supply with a voltage of up to 20 volts. No current specifications are provided. Strangely, the spec sheet goes up to 24 volts. I powered it using my Keysight lab power supply, set to 20 volts with maximum current of 3 amps.
The core of AMP60 is the TI class-D TPA3128D2. In use it barely got warm so perhaps it could run at higher voltage than 20 (rated to 26 volts).
HifiBerry AMP60 Measurements
As usual let's start with our 5 watt output into 4 ohm load using 1 kHz tone:
Distortion is quite high, limiting SINAD to "fair" category in our rankings of nearly 190 amplifiers tested to date:
Note that gain is rather low by typical amplifier specs but perfectly fine to mate to current set of DACs. Maximum output is achieved at around 1.25 volt with 4 ohm so you are good to go there.
The low gain helps it achieve excellent signal to noise ratio:
Crosstalk is very nice as well:
Frequency response though shows typical load dependency we see in this class of amplification:
So depending on the speaker impedance, your high frequency may be softened or exaggerated some.
Multitone shows sharp increase in distortion at both ends of the frequency spectrum:
Power is modest but considering how tiny this board is, shows how far we have come:
Transfer function/graph is quite odd looking and shows the high distortion we have seen. Same is true of 8 ohm response:
Clipping is so sharp that allowing for 1% THD doesn't get you any more power:
Finally, we see the not-so-nice distortion graphs for different frequencies:
And typical drop in power at 20 Hz which sadly is where you need most power.
Conclusions
The AMP60 is a delightful form factor and sports some good measurements such as noise. Alas, it generates good bit of distortion and of course power is modest. For secondary use in a workshop or bedroom, it might be fine if you are building a system around Raspberry Pi and company DAC. You would have to provide a power supply though so price goes up, getting closer to a typical desktop amp.
Despite my emotional bias to like the little amp, I can't recommend the Hifif Berry AMP60 based on its distortion. Wish they had tried harder to produce a more performant product.
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As always, questions, comments, recommendations, etc. are welcome.
Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
While the unit looks like a typical RPi "HAT," it is actually a stand-alone amplifier with no dependency on the RPi computer. It does however have headers for input which mate with company's own DAC (output). For testing, I just wired up a set of RCA cables to the header.
You are responsible for supplying a power supply with a voltage of up to 20 volts. No current specifications are provided. Strangely, the spec sheet goes up to 24 volts. I powered it using my Keysight lab power supply, set to 20 volts with maximum current of 3 amps.
The core of AMP60 is the TI class-D TPA3128D2. In use it barely got warm so perhaps it could run at higher voltage than 20 (rated to 26 volts).
HifiBerry AMP60 Measurements
As usual let's start with our 5 watt output into 4 ohm load using 1 kHz tone:
Distortion is quite high, limiting SINAD to "fair" category in our rankings of nearly 190 amplifiers tested to date:
Note that gain is rather low by typical amplifier specs but perfectly fine to mate to current set of DACs. Maximum output is achieved at around 1.25 volt with 4 ohm so you are good to go there.
The low gain helps it achieve excellent signal to noise ratio:
Crosstalk is very nice as well:
Frequency response though shows typical load dependency we see in this class of amplification:
So depending on the speaker impedance, your high frequency may be softened or exaggerated some.
Multitone shows sharp increase in distortion at both ends of the frequency spectrum:
Power is modest but considering how tiny this board is, shows how far we have come:
Transfer function/graph is quite odd looking and shows the high distortion we have seen. Same is true of 8 ohm response:
Clipping is so sharp that allowing for 1% THD doesn't get you any more power:
Finally, we see the not-so-nice distortion graphs for different frequencies:
And typical drop in power at 20 Hz which sadly is where you need most power.
Conclusions
The AMP60 is a delightful form factor and sports some good measurements such as noise. Alas, it generates good bit of distortion and of course power is modest. For secondary use in a workshop or bedroom, it might be fine if you are building a system around Raspberry Pi and company DAC. You would have to provide a power supply though so price goes up, getting closer to a typical desktop amp.
Despite my emotional bias to like the little amp, I can't recommend the Hifif Berry AMP60 based on its distortion. Wish they had tried harder to produce a more performant product.
----------
As always, questions, comments, recommendations, etc. are welcome.
Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/