Recommendations for getting great headphone sound with Classical Music - amp/dac, players, collection format, etc

I listen to a lot of music, but the most is Classical. I love high quality sound when I can, but the audiophile world is definitely very complex. Here's what I have now, and I'd like recommendations on what other things I can do to improve it. Not looking for headphone advice in the scope of this question, but For headphones I use, I have the HD650, AKG K7XX, Beyerdynamics DT770 that I use. (In the future, was considering the HD660s or even stepping up to the 800 series, but for now I want to focus on the sources) For powering them, I have Schitt stack that I use at my computer, Modi/Magni, as well as a Soundblaster Ae5 sound card with 600 ohm amp. For portable, I have a Soundblaster E5 that I use with my ipad/iphone to power them. At my computer, I listen to FLAC files. (Got some from HD tracks) I also listen to CDs I have ripped, and I stream the Master quality Tidal. I also stream Idagio, a Classical Service that has hi res flac files too. I listen to a lot on my ipad or iphone too, with the E5 sound blaster unit. I stream Idagio or Tidal there, highest quality possible. Here are my questions:
  1. Are my amp/dacs sufficient to give me high level sound on the above headphones? especially portable?
  2. Should I look into a high res portable player like the Astell and Kern for my music listening instead of the iphone/ipad streaming? I want the best sound possible on mobile.
  3. For my computer listening, what's the best I can get? FLAC? Or something else?
In the future when I am comfortable with my collection format and sources, I will look into the headphone side too. No point getting better cans now if I don't know how to best take advantage of them.

Dec 6, 2018
I've had a great experience with classical music on my 6XX paired with my Schiit Valhalla 2 (though I like my DT880 just a bit more for classical). Soundstage is important for classical music and the amp delivers without much in the way of coloration from the tubes. On the format front, and especially with classical, mastering matters far more than digital format. A well conducted, well mastered piece in 192 vbr mp3 will be more enjoyable than a mediocre piece in the highest resolution. My advice would be to focus on identifying and collecting the best recordings of a given piece and don't get too caught up in the encoding format. The Kleiber box set below is a great example, if you don't already have it. Several contenders for best recording of X piece, and in the case of his recording of Beethoven's 5th, a contender for greatest recording ever. If you have the equipment, the included Blu-ray audio version is amazing, but a 320 mp3 rip is well worth the price alone.

Dec 6, 2018
Claiming to drive 600 ohms is a selling point that any amp maker is going to feed you to try to get you to buy their amps. Don't buy it. Learn how to do the calculations or visit an online drive calculator - see @jaydunndiddit's comment below. I do not know of a portable amp that can fully drive HD650 (ifi has an offering that is the closest I know of, but still has a 2V gap to fill on its rails). The sound blaster mentioned falls far short. Don't forget that they were designed long before listening to music was a mobile experience. They are meant to be driven by a desktop amp and most of those can't even do them justice these days. Which magni are you using? If it's not Magni3 it is not capable of fully driving them either. Magni3 just gets you there. Now that that's out of the way: How do you listen? Are you concerned with instrument placement and being able to picture the symphony in front of you or do you just want a rough estimate and great tonal balance to realistically represent the piece you're hearing? This is, of course, the never ending Tube vs SS amp argument. Tubes provide a much more expansive sound stage, but skew the tonal balance of your music. SS provides the most neutral reproduction but with smaller sound stage and less intimacy with your music. It really is a hard choice for some of us. Personally I must have at least one of each type of amp on-hand so I can switch depending on my mood. If you want to be really drawn into your music, I would point you in the direction of getting a decent tube amp (I hear good things about Darkvoice and Bottlehead but I've built all of my tube amps so I'm not overly familiar with which consumer models to point you to). Pair that with a stellar DSD DAC (Topping D50 is a great place to start) and library of DSD files and you're going to feel like you're the conductor. Don't get tricked by folks who tell you that you should be scaling your amps with how much you spend on headphones. I've heard HD650 paired with many a $100 amp and also with a couple of $5k+ amps and must say that they are equally at home on either as long as they are capable of fully driving them. That is a stellar set of cans. That being said, when you get around to upgrading to the HD800 range, make sure you're making an informed decision. Go find a store somewhere and listen to the models you're considering for a good long while. At that price range you've earned a good 30-45 minutes of listening to them in someone's store. I had to learn recently that 10-15 minutes isn't long enough, and was pleasantly surprised by what I ended up with. It would be terrible to have the opposite happen at that price range.
Hopefully, this helps some folks but these are my two biggest resources for calculations and other information. I have others but these two cover 90% of any conversion I may need to do. &
Dec 6, 2018
Thanks. Keep in mind that these show bare minimums needed to get to a certain dB SPL and you need some overhead beyond that to keep from clipping. Anecdotal on that: with HD 650 I hear a substantial difference between 10V rails (can just cover your 120dB peaks) and 12V (can get you to 122dB) rails and built my amp for them to have 18V (can explode my HD 650s) rails due to discernible improvements there.
Honestly, for classical listening, your stack is limiting. You should aim for a completely neutral, clean amp that will give you the blackest background possible (e.g. THX AAA 789). Pair that with a DAC that measures just as well and ideally be used in a balanced configuration to further mitigate any potential noise in your chain. I have this setup paired with an SMSL SU-8 and I can hear the noise floor of the recording before I will hear any distortion from anywhere else in my chain. Throw in the heaps of power AND control that a good amp can bring and you will have a huge upgrade to your music listening with your current headphones. Also, FLAC are fine. But, since you listen to classical, a lot of DSD/Binaural music is classical or orchestral so you could really do well by digging a bit deeper here. The DAC I mentioned also renders DSD files and their various hi-res formats but it does not support MQA (I use an iFi nano BL for my MQA delivery). Personally, I am not a huge fan of DAPs as I honestly don't see the point (but, to each their own). I would look at a used/refurb LG V20/30/40 as you can use the phone and have access to the play store nor does it require service or a sim card to function. All you need is WiFi. It also comes with a very nice Quad DAC and can output 2 Vrms so it will power anything sufficiently except for current hungry planars or and high impedance Senn's (they'll get loud but not sound the best).
Dec 6, 2018
I 2nd this, get a THX AAA amp, your modi will be good enough for now, I recommend a Schiit Eitr to get the max performance out of your dac.
Dec 6, 2018
  1. The amp/DAC is sufficient (and a heck of a bang for your buck). If you want an upgrade in fidelity without spending a lot more, I'd recommend adding a USB decrapifier (like a Schiit Wyrd). If you want a slightly different sound, you can try a tube amp. Output transformer-less (OTL) tube amps and tube hybrids pair well with the Beyer and Sennheiser you have, and will also scale into the HD 800 nicely. Side note; the sound card is redundant with the Schiit stack (although I'm assuming that the soundcard is for games?).
  2. A hi-res portable player can improve sound quality potentially, but I've personally never found them to be a huge improvement (and really cost-inefficient). Portable options just don't have the fidelity that desktop solutions have.
  3. FLAC is a lossless format, so it's technically the best. However, what matters more is mastering. It's very difficult to tell the difference between 320 kBs MP3 vs FLAC on a well-mastered song (unless you know EXACTLY what to listen for, and honestly I don't hear a difference. Maybe time for me to buy new ears.).