DAC Upgrade from Jolida JD100?


My budget Aune T1 DAC/amp seems to have lost its bottom end. I still have to swap out the cable but it's the same cable I had been using. Assuming the amp is boogered, I'm wondering about upping my headphone amp game. The bass is horrible. Tried two sets of headphones.
I hadn't been using the T1 tube DAC, so it prob wasn't the wisest purchase in the first place.
In any case, I'm wondering if getting a more recent DAC/amp and using the digital out of the JD100 will offer any improvement in the resolution? I'm not unhappy with the JD100 in general. Just considering all aspects of a new headphone amp.
I'm using Senn HD600 cans. The bass is OK with the JD100 headphone jack.
I believe I would need a newer DAC to handle hi res streaming. Heretofore I have not streamed hi res but it's something to consider. Would using a newer DAC offer any improvement to the sound of CDs? I realize the digital out of the Jolida bypasses the tubes
Budget around $300. That may suggest getting an amp only and sticking with the JD100's analogue output.
Thanks for any ideas and what might pair well with the HD600's.
cincyjack

Try the Jolida FX Tube DAC III. It will not break the bank. Another affordable alternative, the Schiit Bifrost.

Just a revision to previous post.

Jolida FX Tube DAC III w/ headphone outs. Schiit Bifrost and a Vali

Thanks for the reply.
The no bass issue has gotten a bit weird.
The outputs in question are playing back in mono and seemingly out of phase. 
I popped off the output jacks molex connector and see no obvious wiring issues but perhaps something is going on inside the connector? All wiring appears nominal.
Jiggled all other molex connectors and they are quite snug.
Emailed Jolida. May be headed for the shop.