In trying to get better portable sound quality than our smartphone we’re more often than not required to play cash and carry with a second device: Astell&Kern, Sony and Pono are three of this most popular brands in this field. For many listeners, especially mainstreamers, carrying two devices is one too many. Whilst the odd ‘audiophile’-centric smartphone has made it to market, they’re no match for a separate DAP, especially if your aim is to drive power-hungry headphones.
I’ve tried to lift the iPod Touch and the Samsung Galaxy S5’s headphone game by externalising D/A conversion and amplification with various dongle USB DACs. Results were mixed.
At this year’s RMAF/CanJam Michael Goodman showed a prototype of his i5 iPhone 5-only exoskeleton DAC/amp that promises similar performance to the CEntrance MiniM8. US$299 via the Indiegogo campaign gets you one of the first 100 units.
Californian newcomers SoundFocus are now offering a proposition similar to the CEntrance i5 but for considerably less cash – obviously, how they compare at this stage is a big unknown.
The SoundFocus Amp iPhone case will sell for US$129 when it hits stores in early 2015 but the current pre-sale price is US$79, presumably discounted in order to gauge demand and generate funds for an initial production run.
SoundFocus’ press release puts heavy emphasis on the Amp built-in loudspeaker from which you’ll get 7 hours constant playback.
“Amp’s sophisticated audio engine and high quality speakers create an unparalleled experience for phone calls, music, games, and movies. The Amp case includes powerful 14×20 mm drivers and a 6 cubic centimeter acoustic backflow volume to deliver warm, rich bass notes and crisp highs. Amp’s audio architecture is complete with ARM M4 processor, 24-bit digital-to-analogue converter and a headphone amplifier.” runs the blurb.
Experienced audio folk will likely cast a jaundiced eye over its ‘room-filling’ promotional promise but the headphone output’s 20 hour run time and externalised D/A conversion made me look twice.

I pushed co-founder Alex Selig for more information on the Amp’s DAC chip and headphone output stage.
“We’re currently using a Maxim MAX98090 but are considering changing to another DAC before we ship. As such, we don’t have the final power ratings numbers. Amp will ship with low distortion, 24-bit/48kHz sound that works well with the full range of high impedance headphones from standard 16 Ohm earbuds to high impedance 250 and 600 Ohm over the ear headphones.”, says Selig
Whilst this highlights one of the problems of quasi-crowdfunded production pre-sales – the specifications can change after you’ve dropped your dollars – the Amp sure looks promising. It’s price low enough for some to take a punt.
If the Amp fulfills its promise of improved iPhone sound whilst lifting the phone’s battery life by 25% then I’d say that’s a win for anyone who anyone who snags one.
The Amp will be available in black or white versions to fit the iPhone 5/5s, iPhone 6 and iPhone 6 Plus.
Further information: SoundFocus Amp