The FiiO E5 and E6 are twins but this does not mean they are identical. Although they share particular similarities, it would be a mistake to consider them interchangeable or to overlook the distinct characteristics of each. Each amp offers particular qualities that make them unique and better suited for different tastes and demands. In the following, the E5 and E6 will be compared and contrasted on various points including construction, user interface, and most importantly, sound.

Construction

FiiO E5

At first glance, the E6 shares one obvious quality with its younger predecessor: portability. Like the E5, the E6 is remarkably compact and easy to take anywhere. Both units are designed to seamlessly integrate with portable music devices for powerful headphone amplification in virtually any setting.

FiiO E6

Where the E6 begins to differ from the E5 is in its construction materials and design. Unlike the E5 which featured an aluminum housing with matte black finish and a fixed clip of the same material, the E6 is constructed entirely out of plastic and finished with a glossy black coat. While the plastic construction of the E6 is may initially taken to be a shortcoming of the E6, it is sturdy and can reliably withstand the regular jostling that portable devices must be able to endure. Unfortunately, the glossy finish of the E6 is prone to unsightly scratches and smudging in a way that is absent from the E5. Moreover, the fixed clip of the E5 has been replaced by a removable plastic clip on the E6. A removable clip offers users the advantage of opting out of using a clip, but has effectively sacrificed the structural integrity of the clip. The E6 plastic clip is not as sturdy as the E5’s fixed clip. Perhaps in an effort to address the strength of the clip, FiiO includes two clips with the E6.

Features and Interface

Beyond their appearance, the user interface of the E6 has been completely redesigned from that of the E5 and includes new features not found on the E5. A single sliding switch allows

FiiO E6, Sliding Switch

users to toggle between three EQ setting and holding the switch in position for 3 seconds turns the E6 off. EQ settings and charging status are indicated by a color changing LED that reflects through a plastic edge on the cut-away corner of the E6 for a sleek and attractive look. Unlike the E5 which featured a flat or  bass boost selection, the E6 features more options in the way of EQ settings. Users have the option to select from flat, EQ1, and EQ2 bass boost settings each applying a noticeable change in sound character. Unfortunately, more does not mean better.

In this case, the bass boost settings of the E6 are notably overwhelming. In particular, the EQ1 setting might be exactly what bass-heads are looking for but poses a noticeable problem for individuals seeking a complex and detailed bass response.  The EQ2 setting delivers a palatable alternative to the gushing bass, but does not offer the type of clear and balanced bass of the E5’s single bass boost setting.

FiiO E5 Controls

Nonetheless, one aspect in which the E6 does carry a clear advantage is in volume adjustment. While the volume adjustment button has remained the same, the E6 offers a 64 step volume gradient compared to the E5’s 32 step volume gradient. The expanded volume gradient allows users to personally define the volume level. On the other hand, the E6 and E5 are both silent in their adjustment, allowing users to change the volume levels without interfering with the quality of the reproduction–a reproduction which is impressively clean and neutral.

Sound Quality

Like any good amp, the signal should not be tainted by the amp’s circuitry. On this count, the E6 delivers surprisingly well. Unlike the E5 which is slightly colored by hiss, the E6 features reduced hiss and does not have perceptible coloration on its default flat setting. Even at high volume levels, the hiss remains low. Moreover, the E6 does not produce a loud pop when turned on and prevents damage to the drivers from the sudden spike in voltage. The absence of a loud pop is also a quality that the E5 proudly shares with many FiiO amps including the E6.

Conclusion

Both the E6 and E5 are excellent portable amps. Both headphone amps deliver a neutral response with low distortion levels across the frequency response. Each have the ability to drive high impedance headphones with reliably powerful output. Whether you choose to the E5 or E6, neither will be a sacrifice in quality. It is really a matter of what preference. I personally own the E5 and it suits my purposes especially well– nothing is quite as thrilling as listening to Richard Wagner’s “Der Fliegende Hollander” with a bass response that really makes the instruments breathe. Either way you go, FiiO E6 or E5 will both deliver high quality.