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Tension Labs EAP03 Earphone Audio Processor
I'm not usually one to ignore the chance to ridicule grandiose nomenclature, so when I was first introduced to the Tension Labs EAP03 by our resident newshound, Mr Kelly, my first temptation was to mock the name. After all, it's really just another portable headphone amp, isn't it? For once, no. The EAP03 is both much more and just a little less than that.
Released some time ago in the US, but now being introduced to the UK by the guys at Advanced Communications Solutions, the EAP03 is designed to accompany your MP3 player and earphones - more specifically in ear monitors - both on and off the road. The point about IEMs is important. While other portable headphone amps, like the iBasso Boa D2, are aimed more at larger, over the ear headphones - though they also work wonders with demanding IEMs like the Klipsch Image X10s or Shure SE530s (aka the E500PTH) - the EAP03 is focused squarely on the type of thing you wedge into your ear canals. You can use it with full-sized headphones, but that's not really where its strength lies. You see, on top of basic amplification, the EAP03 also provides a range of features aimed at optimising and enhancing the output from IEMs, and making using them a little more practical while on the move.
Measuring 82mm x 53mm x 13mm, the EAP03 has a similar profile to an old iPod mini, and at 55g it's both smaller and lighter than competitor products like the aforementioned D2 or the Graham Slee Voyager Amp (though of course not the miniature E5 and E3). The design is fairly simple, with a 3.5mm input, a 3.5mm output and a mini USB connector, a jog dial on the side and two buttons, a two-line monochrome LCD screen and a microphone on the front. Despite the plastic construction build quality is generally sturdy, and a number of stick-on Velcro patches are provided so you can affix your player to the EAP03 for easy transport. The only other accessories provided are the USB cable (for charging) and a short but chunky 3.5mm to 3.5mm interconnect, for hooking up the input on the unit to the output from your player of choice.
For power, the EAP03 uses a built-in lithium polymer battery, which takes two to three hours to charge and lasts for seven to eight hours at a time. That doesn't compare brilliantly with the iBasso D2, but it's enough for everyday use, if not a weekend trip or long-haul flight.
The EAP03 takes a little more setting up than your regular headphone amp. First of all, you need to know the sensitivity rating of your IEMs in dB/V at 1KHz. Some common Shure, Ultimate Ears and Etymotic models are listed in the manual and you can find more detailed on the Tension Labs website (http://www.tensionlabs.com/support.htm), but you can easily find the information yourself if you need to with a visit to Google.
Once you have this info, you can set up the EAP03 by using the jog dial to flick through the settings and the Audio and Mic buttons to make adjustments. First you set the Earphone Sensitivity, then you set the Amp Gain accordingly - without these two steps, you won't get a great result from the unit. In fact, you'll probably make the sound worse than it is through your player's regular headphone output.