It's now been almost 6 months since FiiO launched their top-of-the-line X7 DAP and impressed the hifi community with it's sound quality to price ratio. Whilst many reviews mentioned the ease of use and powerful DAC chip, the majority reserve the most praise for it's modular amplifier system; allowing you to physically alter the unit depending on your listening habits. These modules have also been confirmed to have compatibility with the upcoming FiiO Q5 DAC. Now, with the recent announcement that FiiO will be producing the X7 body separately (as the standard edition), we thought it a good a time as any to explain the ins and outs of using these amplifiers so you can construct the perfect X7 for your tastes. Here is AVShops' guide to the FiiO modular system.
The New Standard
FiiO have been very candid in explaining the slightly bendy way in which the X7 was released, notably accepting that the AM1 IEM module was included to make it as accessible as possible whilst lowering it's overall sound quality. This was quickly remedied with the release of the AM2 Medium-power and AM5 High-power modules which both opened the X7 to previously unattainable heights of sound reproduction. However, the fact remained that you still have an AM1 module lying about, even if you only listened through high impedance headphones. FiiO now hope to remedy this by only selling the X7 in it's new Standard configuration; removing the AM1 and selling it separately. This allows you to decide which amplifier suits you best when initially buying an X7 and drastically reducing the price in the process. However, it is worth noting that you will need at least one module for the X7 to successfully work as the Standard Edition lacks any USB functionality and therefore any means to charge it. Luckily FiiO are releasing a new module to account for this; the AM0.
Simplicity itself; the AM0
This brand new module is different from the others in that it specifically lacks any amplifier chip, thereby turning your X7 into a pure audio source. You are then free to use any FiiO or third party amplifier to boost the sound out of the X7's line out, extending the battery of your X7 in the process. The AM0 also retains the microUSB connector found on FiiO's other modules, meaning it can dock happily with the FiiO K5 and upcoming DK1. You can even access the brilliant Sabre ES9018S DAC chip from your computer, providing a massive boost to your desktop audio! A simple module for the simplest of uses.
IEM Original; the AM1
The AM1 got a little bit of flak when it first appeared, bundled to the X7 on it's first release. A few loyal listeners were upset that FiiO had decided to include a fairly modest in-ear monitor amplifier instead of something crackling with power. Personally I can see FiiO's logic as the majority of portable listeners do so with IEMs and earbuds, saving over-ear headphones for critical listening at home and this is a market FiiO wanted to tap. The amp itself is a fine thing which trades thumping power to extend the X7's battery life up to 9 hours. Though even then the AM1 uses a similar chip arrangement to the brilliantly tuned A3 which can drive precise IEMs cleanly with a wide sound reproduction. A solid starter unit and more than able to hold its own individually.
Over-ear Surprise; the AM2
What nobody quite expected after the mixed reactions to the AM1 was quite how much the AM2 would boost the capabilities of the X7; fast becoming the go-to module for intermediate and advanced listeners alike! Something clearly helped by it's equally assured use with low impedance on-ear monitors as with IEMs. That's right, the AM2 can also get wonderful audio out of IEMs in part due to sharing the same MUSES02 opamp as the E12a IEM amplifier. The caveat is that battery life is reduced in comparison to the AM1 but luckily not by deal breaking amounts (c.8 hours with AM2 compared with c.9 hours with AM1). This is a great choice for those who want solid performance across a variety of headphone types.
Balancing act; the AM3
This mysterious module features both a regular 3.5mm output and a secondary balanced output for (unsurprisingly) balanced headphones. In simple terms for those out of the know, a balanced output gives you a purer signal. In slightly more complicated terms; a balanced output sends two identical source audio signals down one cable; the signal structure of one of these is inverted so that they cancel each other out; when they reach the destination (a speaker or headphones) this inverted signal is inverted again which in turn inverts any noise the cable would have picked up; this then cancels out the noise present in the other signal, giving you clear audio. Balanced audio takes away any interference picked up between your source and your ears and is a must-try for any intermediate audiophile.
Ultimate Power; the AM5
Of course, sometimes subtle nuances are not enough and what you really, really want is all of the power. If so, then the AM5 is the module for you! By using a Texas Instruments TPA6120A2 headphone amplifier chip more commonly found in desktop amplifiers, FiiO have managed to up the output power to a whopping 800mW (with 16 ohm impedance headphones). This gives you ample maneuverability and enough drive to run even the trickiest over-ear headphones in a portable set-up. Much like the AM2, the only drawback is a reduced battery life (c.6 hours) but considering the audio heft this gives you, it's a fair compromise!
Of course, this is just the beginning. As mentioned before, FiiO has opened up these modules to 3rd party designers and there are a great many ideas floating around the boards over at Head-Fi so the future is looking bright. Add to the fact that the upcoming Q5 DAC has been confirmed to use the modules and with next generation X1s, X3s and X5s on the horizon, who knows where this brilliant adventure will take us next!