Combo DAC/AMP for Headphones

Audio-gd  makes some really nice AIO with R2R technology  . I had R-28. It was very nice sounding

    I've been very happy with multiple trade-ins from HiFiMan.  Traded up an EF400 to EF600...they have a special for this now.   The Serenade DAC/Amp has good reviews, and there is a "Junior Serenade" now also.

  The EF600 is mainly sounding great with Arya Unveiled HPs. I had some HE1000SEs that were amazing on it also.  It will power my Susvara too, but they sound better on a Pontus II/ Holo Bliss KTE stack.  The dual Hymalaya Pro DACs tame most of any hi frequency overreach on some HiFiMann HPs, but are still "revealing".  Big stack has more everything tho...detail, smooth, full 12w@32ohm power.  

    Many deals on the HiFiMan web site right now.  Gees, I sound like a HIFiMan shill...not true, there's a lot of great headphone equipment now days from many manufactures!  Golden Sound is my favorite reviewer.  Have fun, even my old Sundara on a Schitt Stax are still very enjoyable.

Have Cable Company send you a few to demo. Why take a chance when you can listen for yourself?

Have you considered a used T+A DAC 200?   It is a superb DAC and a very good headphone amp.   I have one.