Hello there! I have been going deep into the rabbit hole of trying to find something new to upgrade to. I mostly listen to j-pop, pop, hip hop, DnB, and a ton of metal. So I’m looking for something that is able to excel in those categories. I have the Valhalla 2 for an amplifier and a Topping D30 DAC so I already have equipment. I don’t mind buying another amp if the headphone is like that good but something to pair well with that. I know I think I need something with a bit more bass. I have been looking at around 1100 for my limit and this includes used stuff as well. Thank you in advance!
I’d look into the Focal Elex or a Sundara. I’d also caution you against selling your 6XX and current setup. The 6XX should pair great with your current amp.
The Elex is a great upgrade from the 6XX (better bass & treble) but the 6XX already has some of the best mid-range out there. I will caution you that my Elex is current awaiting replacement from Drop due to a defective driver (left side lost bass response and would buzz instead… took a week to arrange an RMA, going to take another week before they ship a replacement).
The Sundara is a great planar headphone. However, the bass is different than a dynamic driver (I could go on, but I think it’s something that needs to be experienced to understand). But while the bass isn’t (at least for me) as satisfying as a good dynamic, the treble and detail retrieval is amazing. You can listen to the craziest shit and the driver is fast and light enough to contain it. I’ve heard stories of some folks having issues with Hifiman headphones, but mine are fine. YMMV.
With either the Sundara or the Elex you’ll probably want a more neutral amp. I currently have an A90 for reference sound, 353X for eStats, Liquid Platinum for warmer sound, and Valhalla (1 not 2) for that tubey sound. All fed from a D90 DAC (RCA to Valhalla, everything else fed through an XLR switch).
If you decide to get a balanced amp, I’d recommend picking up a decent balanced DAC. Not because I think balanced is better, but the balanced amps I’ve tried don’t sound right when fed through RCA. I haven’t noticed any issues from cross talk or distracting distortion from single ended sound, so I don’t think that balanced headphones make a lot of sense unless your signal chain was designed with it in mind.