I'd look at the Etymotic ER2XR. They are more or less industrial earplugs.

Sounds like you've hit the limit of the Fulla. I bet it's going into protection mode. The Aeon is a power-hungry headphone and the Fulla isn't particularly powerful.

Yeah, kinda. I'm not a fan of the Zen series for a few reasons, but they aren't bad. Do you know the seller?

You could get an HD650/600 for 200 euros, and I don't think the Zen stuff is worth 350 unless you really want the fixed EQ presets. If you'll be listening from a PC then you can do the same adjustments for free.

It's the low efficiency of the K702 that makes them hard to drive.

I'd get a Fiio KA3. It's under budget new from a store. I think it comes with a lightning cable.

I'd ask Beyer if the drivers are the same or not. In any case, I'd expect a little bit of channel imbalance since the drivers aren't matched. Unit variation is very much a factor.

Focals have been known to have problems with driver excursion when bass is played at high volumes. The diaphragm basically hits its end-stop. Tell him to stop blowing out his ears with ridiculous volume and stop worrying. The headphones are most likely completely fine.

Unless you're running EQ then there shouldn't be a possibility of any clipping problems.

Anyway, you would lose a little bit of dynamic range. Probably not enough to make a practical difference.

In some ways, yes. The Edition XS might be better.

I would not bother with going balanced. Especially not when you're only going to use IEMs.

https://benchmarkmedia.com/blogs/application_notes/audio-myth-balanced-headphone-outputs-are-better

I'm sure there's a giant thread about this on head-fi.

Bass probably isn't its strong suit.

I certainly did. Especially with a set of ZMF suede upgrade pads.

You can't really get a significant upgrade from the 650 on that budget. The Focal Elex fits your requirement for punchy bass.

The Magni 3+ seems like a good choice as long as the warranty isn't any worse.

Take a look at the Final Audio E-series.

I'm not sure if I would buy a used earphone from a stranger. Ear gunk and stuff... If you're after wow-factor, then the 7Hz Timeless might be just as good.

After a bit of Googling, I'm pretty sure they are practically identical.

I assumed that wasn't a concern since you didn't specify a budget. In fact, you didn't specify a lot of things that could help me give you a better recommendation. There's a template linked in the OP.

I don't think the Zen DAC has this functionality. You'll just have to turn off the speakers and unplug the headphones as needed.

Most usually not from a power perspective, and there's a lot of misunderstandings going around. Watts are voltage × current, and some headphones need proportionally more of one or the other. That's one of the reasons why it is generally good to leave some headroom when specing a setup just based on wattage. Then some people take this argument way too far and draw the wrong conclusions.

Depending on who you ask, and there are credible people on both sides of the argument, some headphones may sound nicer on certain amps. But then we get into the weeds of equipment that don't claim full transparency to the source and do introduce colourations. Also, you might need to consider the question of whether or not it's good to listen to recordings using equipment more perfect than what it was originally made with. Yadda yadda... We can go on forever.

Fundamentally, if your idea of listening is to replicate the source file as accurately as possible (according to current standards of analysis), then a THX amp is all you'll need for everything apart from the most ridiculously demanding headphones.

Hifiman Susvara

If a device has both balanced and single-ended outputs, you should try to use the balanced one.

You need a cable that's wired for balanced use. Take a look at stores like Linsoul. You can specify most cables to have the appropriate connectors at both ends.

The K72 is hot garbage. I'd return it.

I don't think it's an in-line resistor. My bet is on a voltage divider. There is still resistance/impedance in series, but it should be less.

Oratory's setting is made by hand and validated. AutoEQ ones are just mathematically calculated. But honestly, just use the one you like to listen to more.