The iPhone will drive the headphone fine and make a very nice sound, but the amp will make a big improvement in harmonic extension and soundstage. Use the amp whenever possible. Both Headfonia and I concur that the E07k is a great amp, and probably the best thing you can get for up to twice the price. I’m familiar only with the E07k, the E17, and the E12. I think the E07k beats the E17 (and both are also USB DACs), while the E12 is just an amp, and has a darker sound but with more power for inefficient headphones. The Philips is not inefficient.

The SoundSport Wireless are wireless sport earbuds that are very similar to the SoundSport Free. Instead of being true wireless earbuds, however, the two SoundSport Wireless earbuds are tethered together by cable. Aside from that, the two wireless earbuds have similar audio performance and use the same Bose Connect app. The SoundSport Wireless will last longer on a single charge (as opposed to the SoundSport Free which recharge every time they go back in their case).
Their combination of dual balanced-armature drivers matched with a dynamic driver to pump up the lower end are kind of engineering normally found on products that cost more than double the price of the 1Mores. Even the smaller details are very well ironed out, such as Kevlar-wrapped cables that increase resistance to wear while simultaneously reducing tangles.

The FiiO E17 “Alpin” + AIAIAI TMA-1 or Pro700 Mk2 seem like a mix you’d recommend, but I’m concerned those cans will be uncomfortable for day-long use.  Also I don’t know if that DAC/amp is the best for my style of music/headphones.  Third, some of my techno tracks have stunning vocals, and I don’t want to miss out on those high notes while enjoying the bass.
The design is not mechanically stable; a slight imbalance makes the armature stick to one pole of the magnet. A fairly stiff restoring force is required to hold the armature in the 'balance' position. Although this reduces its efficiency, this design can still produce more sound from less power than any other[clarification needed]. Popularized in the 1920s as Baldwin Mica Diaphragm radio headphones, balanced armature transducers were refined during World War II for use in military sound powered telephones. Some of these achieved astonishing electro-acoustic conversion efficiencies, in the range of 20% to 40%, for narrow bandwidth voice signals.
Preferences for the length of headphone cables vary for portable users, especially depending on where you prefer to wear your device: a backpack or a pants pocket necessitates a longer cable, while you'll opt for a short one when wearing a player on a neck lavalier or an armband. But a cable length at either extreme need not be a fatal flaw: extension cables can lengthen those that are too short, and cable wraps can tighten up ones that are too long.
In the professional audio sector, headphones are used in live situations by disc jockeys with a DJ mixer, and sound engineers for monitoring signal sources. In radio studios, DJs use a pair of headphones when talking to the microphone while the speakers are turned off to eliminate acoustic feedback while monitoring their own voice. In studio recordings, musicians and singers use headphones to play or sing along to a backing track or band. In military applications, audio signals of many varieties are monitored using headphones.
The outer shells of in-ear headphones are made up of a variety of materials, such as plastic, aluminum, ceramic and other metal alloys. Because in-ear headphones engage the ear canal, they can be prone to sliding out, and they block out much environmental noise. Lack of sound from the environment can be a problem when sound is a necessary cue for safety or other reasons, as when walking, driving, or riding near or in vehicular traffic.[19]
hum..I see your point…The big concern to me is that, since I don´t live in USA, everytime I order a pair of cans if I don´t like it I sell it….That´s the reason I will order starting with the most popular brands… it will be easier for me to pass a senn than a superlux, for instance. You know what I mean? Since you have mentioned 598 and HP100, can you please tell me who wins in terms of soundstage, spaciousness, and good separation?
While Apple’s AirPods get a lot of attention for how well they work with other Apple products, there’s actually a more affordable option that’s just as tightly integrated: the Beats BeatsX Earphones. Apple owns the Beats brand, and it’s built the BeatsX earphones with the same W1 chip that’s in the AirPods. That means that the user experience is virtually identical – iOS makes it super easy to pair them with any iPhone or iPad. Our favorite part is they have a Fast Fuel feature, so when your battery is low, plugging them in for five minutes provides two hours of talk time. We’re also big fans of the COWIN E7 Headphones. They’re wireless, they’ve got on-board noise cancellation, and they can last up to 30 hours on a single charge. The E7’s have an impressive spec sheet for any price point, but the fact that they’re so affordable makes them an even better value. If you’re looking for affordable over-the-ear headphones that don’t make any compromises, this is the pair to get.
The moving coil driver, more commonly referred to as a "dynamic" driver is the most common type used in headphones. It consists of a stationary magnet element affixed to the frame of the headphone, which sets up a static magnetic field. The magnet in headphones is typically composed of ferrite or neodymium. A voice coil, a light coil of wire, is suspended in the magnetic field of the magnet, attached to a diaphragm, typically fabricated from lightweight, high-stiffness-to-mass-ratio cellulose, polymer, carbon material, paper or the like. When the varying current of an audio signal is passed through the coil, it creates a varying magnetic field that reacts against the static magnetic field, exerting a varying force on the coil causing it and the attached diaphragm to vibrate. The vibrating diaphragm pushes on the air to produce sound waves.
The Elite Active 65t come with three sets of silicone tips and feature an ergonomic design that guarantees a good seal, which is a big reason we prefer them to other true wireless models. With outstanding comfort and excellent passive noise isolation, you get the most out of every note, and you can also lower the volume for less ear strain. Overall sound quality is solid, and sound comes through clear and balanced, with a punchy bass response and a surprisingly dynamic treble range.
The FiiO E17 “Alpin” + AIAIAI TMA-1 or Pro700 Mk2 seem like a mix you’d recommend, but I’m concerned those cans will be uncomfortable for day-long use.  Also I don’t know if that DAC/amp is the best for my style of music/headphones.  Third, some of my techno tracks have stunning vocals, and I don’t want to miss out on those high notes while enjoying the bass.

Inexpensive: Most casual users can find a good pair of headphones for between $20 and $50. Headphones in this price range sound great, include key features like an in-line microphone, and often support wireless Bluetooth connections. If you’re looking for a reliable set of headphones and you don’t need much more than audio, you don’t need to spend more than $50.

Smaller earbud type earpieces, which plugged into the user's ear canal, were first developed for hearing aids. They became widely used with transistor radios, which commercially appeared in 1954 with the introduction of the Regency TR-1. The most popular audio device in history, the transistor radio changed listening habits, allowing people to listen to radio anywhere. The earbud uses either a moving iron driver or a piezoelectric crystal to produce sound. The 3.5 mm radio and phone connector, which is the most commonly used in portable application today, has been used at least since the Sony EFM-117J transistor radio, which was released in 1964.[9][10] Its popularity was reinforced with its use on the Walkman portable tape player in 1979.