Advice needed for upgrade path

I'm a headphone junkie. 

I only use 3 amps, but have many HPs.

My favorite amp is a Woo WA22. You can go crazy (and broke) rolling tubes, but by doing so will give you many flavors of sound. It is an OTC amp and works well on all my phones. 

My Schiit Jotunheim is Solid State with a ton of power and is fully balanced as well as the Woo.

The biggest surprise is the Apos Gremlin. It is a tube hybrid running balanced only and costs a whopping $120. It looks like a starter DIY kit, but sounds awesome.

My mostly used headphones are Focal Utopia, ZMF Verite Open, Sennheiser HD800, Fostex TH900 v2, Abyss Diana Phi, Hifiman HEX, Audeze LCD2, Pioneer SE Master One, and the ones I would recommend for you, the JM Audio XTC Open headphones. You can choose from Biowool or Beryllium drivers, and they will tune them to your preference. If you don't like the initial tuning, they will re-tune them for the cost of shipping. John, the owner, is super to work with. I just ordered the new Megaverse model, and he called me to confirm all the tuning options before finalizing the order. Who else does that? On top of that they are cheaper than most TOTL headphones. Sorry if I sound like a fanboy, but no other company has impressed me as much. John is very knowledgeable about amps and willing to discuss those with you also.

Good luck on your journey!

Definitely check out Head-fi.org.

They are one of the most knowledgeable groups, and have a great classified section.

@treepmeyer Amp/dac is Peachtree Gan1 modded by Ric Schultz.

I also had the GAN1 modded by Ric and wrote about it on A’gon.  I was at one time using the GAN1 amp to drive one of the best replacements for a 2-channel music system, the RAAL SR1a or SR1b.

The reason I describe SR1a as a replacement is because it is an open baffle design with 2 flaps hanging over your ears, like mini speakers. The only issue with this phone is that it is bright, so you need some warm-ish gear in front of it. 

Raal SR1a ribbon headphones and Schiit Jotunheim R direct drive headphone amp For Sale - US Audio Mart

The GAN1 is not warm but it is not bright either and worked well with the SR1a. Now the best amp for the SR1a is my RAAL VM-1a. It is no longer available for sale, but I did recently see one on USAM. I also have a Schitt Yggi+ OG DAC | Schitt Kara F preamp | Schitt Aegir v1 amp to drive my SR1a, but it is not as good as the VM-1a.

Now if you got a bit of funds and want the very best, but it sounds more like headphones and not 2-channel, is the $10k RAAL Immanis. It competes with things like the $80k Sennheiser HE-1.

Look at all the WANTED ads on USAM for the Immanis. The Immanis is much easier to drive than the SR1a and the GAN1 WILL NOT work with the Immanis because it may damage it with all the power.

Send me a DM on A’gon if your want more info on the RAAL line. I must have spent about $30k over the past 5 years 2-channel amp ’rolling’ for the SR1a. Along with a multitude of DACs for the phone. I love the SR1a. Of course, I made some money back when I sold the gear.

@hillbilly559 Thanks for all the info, especially about JM Audio.  I was not familiar with them.  Reasonable prices for what looks like great products and service.

@yyzsantabarbara I bought the Gan1 and had it modded partly on the basis of what you posted on Agon.  I have not been disappointed.  Thanks for that.  The Raals look fantastic but are more than I want to spend, at least for now.  I am setting my headphone budget at $2k for now.  I think that will get me a significant upgrade from the HD650s.  I'm afraid if I spend more I simply won't appreciate it.  My ears need some training.

To support whatever new cans I get, I'm leaning toward a tube amp, say from Woo or Feliks.  Upscale has a couple of Feliks Echo MKII amps for under $1k.  I'd pair that with an appropriate streamer/dac.  Perhaps the Fiio S15. In any event I think of my goal now to assemble an entry-level high end headphone system costing maybe $4-5k and then see where that takes me.

You might also add the QuickSilver headphone amp to your list as it’s highly regarded and at $1200 is attractively priced, but one potential downside is it’s not balanced if that’s a requirement.  Just another option FWIW. 

https://quicksilveraudio.com/products/headphone-amplifier/