If there is one major question that I get all the time is how to improve the Raspberry Pi streamer performance. The most obvious choice is to upgrade the power supply.

What the RaspberryPi.org suggests is to go with a 2.0 Ampere 5V switching mode power supply (SMPS from now on) for the Raspberry Pi 2 or a slightly stronger 2.5A for the Pi3 recently launched. Most users, including me, usually start with a cell phone USB power supply which is enough to power up a Raspberry based streamer. Goes without saying that there is a huge difference between powering up and making the most out of your streamer. That is because the vast majority of SMPS are full of noise and unfortunately that noise ends right into the delicate streamer’s circuits.

A solution would be to build your own linear power supply but not everybody is up to the task. A great alternative is the iPower, a sophisticated ultra low noise SMPS from British manufacturer iFi Audio.

There is more than one version of the iPower but we are interested in the 2.5A/5V one which fits perfectly the bill for our needs. iFi provides an adaptor for microUSB along with a series of extra tips for other uses and four interchangeable mains adaptors suitable for EU, UK, US and Australia. Had the chance of testing it both in Eu and the US without problems whatsoever.

What makes the iPower special is the Active noise canceling technology it packs.

iFi explains:

By generating a signal identical to the noise signal but in the exact opposite phase, it actively cancels all the incoming noise. With ANC+® the power line is filtered for audio band and RF noise. The measured noise floor of 1uV (0.000001V) is at the measurement limit of what even the most sophisticated Audio Precision equipment is capable of.

I kept the iPower in my system for three months and went back and forth several times between the iFi and my home-brewed 5A/50W linear power supply without noticing any major differences. Actually without noticing any minor differences either. To be honest I cannot be even sure if there are audible differences between the two and this is probably the biggest compliment one can do to a switching mode power supply. Back when I first tested the linear power supply against the run of the mill SMPS I was using in the first days the difference in sound was noticeable so iFi has obviously performed some magic with the iPower. Highly recommended!

Specifications

• Input: 100-240VAC
• Output: 5V/2.5A; (Other iPower options include: 9V/2.0A; 12V/1.8A; 15V/1.5A)
• Output plug: 5.5×2.1mm
• DC Adapters:
• 5.5×2.1mm input/5.5×2.5mm output (‘C’ black)
• 5.5×2.1mm input/4.8×1.7mm output (‘F’ black)
• 5.5×2.1mm input/4.0×1.7mm output (‘G’ black)
• 5.5×2.1mm input/3.5×1.35mm output (‘H’ black)
• 5.5×2.1mm right-angled extension cable.
• 5.5×2.1mm input/5.5×2.5mm output; Reverse Polarity Plug (‘C’ white)
• Noise*:   ~1uV
• Size: 82x43x40 mm
• Weight: 155g (with cable)
  * Average audio band noise floor

MSRP: 49€/ $49

Associated equipment

• ATC SCM 100SL speakers
• ASR Emitter I HD amplifier with external Akku
• DAC: Rockna Wavedream (MSB Platinum version)
• Headphones: Audeze LCD-X headphones, HiFiman HE-500, Sony MH1C In Ear Headphones
• Cables: Signal Projects Hydra speaker cables, Signal Projects Apollon interconnect, Black Cat Triode RCA interconnect, Stereolab Superleggera Blue interconnect, Belkin Gold USB cables
• Raspberry Pi 2 streamer (linear PSU, Moode OS, Archphile OS)
• Synology DS215j NAS