i feel like iām beating a dead horse, but you should look into a cheap ddc like the u2 pro since you have an i2s input. the clarity jump is pretty huge. i tried it on a d90 akm variant and it was a pretty big jump in quality especially in the super low sub bass around 20hz. before it sounded ok but afterwards you can distinctly make out the ups and downs of the sine wave frequencies at that super low bass level and the blackness of the background got even quieter and it made for a more realistic and pinpoint accurate soundstage. even the cheap douk u2 pro is a pretty damn big upgrade with headphones that are resolving enough to make use of it. i even have a spare one sitting around if you want to try it before you buy. iām sure it wouldnāt cost hardly anything to ship.
Yea I may pick one up to test whether or not I perceive a difference in sound. What I2s cable would you recommend to connect the D90se to the Douk 2 pro?
I use https://www.amazon.com/dp/B0016CHWC0. I havenāt tried anything other than that one because Iāve heard the shorter the better so I just got a heavy gauge 1 foot cable.
Beat away, my friend! Itās true. I wasnāt going to pay the tag for the Singxer unit but this little Douk U2 Pro has made a huge difference for me. I canāt explain it any better than you just did, so I will use the tried and true āYeah, what he saidā line here!
I tried the su-2 and I actually preferred the U2 to it and I wound up getting the upgraded version and itās ever so slightly better but not really worth the extra $100 but itās there. It doesnāt work with Atmos, though, which I occasionally use for gaming so I just leave both plugged in lol.
Alright I picked one up and the cable. Should be here next Monday due to the holidays. I will report back my findings here.
another ddc option that is an alternative to Singxer a bit more premium to U2. Canāt speak to performance level but itās reviewed favorably in most places and Mon preferred it so that speaks for itself.
For those interested in rolling some Sparkos op-ampsā¦
Use code for 30% off: BlackCyber30
pretty sure this is the model I have of them:
Dual Discrete Op Amp SS3602 - Sparkos Labs, Inc.
Just go to make sure you get the ādualsā and you can buy a pair or 4 at a time to roll in.
Yes this one looks pretty good. A good option for down the road. The tag is a little high, though. I still struggle with that. Itās one of those foundational things that seems to be worth the investment, however.
How would these compare to the current Vivid op amps that comes with the Soloist? What are the expected sonic differences that might occur with this change?
i havenāt done a ton of a/b testing with them but the sparkos have a touch more detail and dynamics and are a bit too peaky in the treble for me on most of my headphones but i could see them pairing really well with a warmer headphone and the v6 vivids have super hard attack speed and makes for some really nice slam. i do really really like the sparkos but i have a lot of bass light headphones or headphones that are just epic with more bass attack so i keep them in but every once in a while i put the sparkos in. i much prefer the sparkos while gaming but iām not swapping opamps just for the slight bit of detail for gaming, though it is nice. i would bet that depending on your headphones it could go either way with preference but i think i have too many that border on sibilance as is and that tiny bit of extra treble pushes them over the top from time to time but a global EQ solves it easy.
For me the vivids are a bit of a U shaped curve with more bass elevation and slam along with treble sparkle and extension. The sparkos are much flatter in presentation.
I bought the 3XP to primarily pair with my 1266 Phi TC so it needs all the help in the mids it can get an 0 emphasis on bass and treble peaks. I find I lose a tough of bass slam and some sizzle up top in exchange for more better technical performance and resolution through the mids. For many of my other headphones I think the Vivids were slightly better (LCDX, LCD3F, OG Clears). But I have other amps for them so I havenāt swapped the vivids in for months.
I also do not have the supercharger (en route) so cannot comment on pairings of op amps with the SC.
Thanks for the feedback @rmsanger and @Pokrog.
It sounds like maybe I would not care for swapping the op amps at this time. Currently my two go to headphones are the V3 Arya and the new Meze Liric. Both sound great as they are right now, and since both headphones lean more towards a neutral bright signature itās probably best to leave well enough alone.
I have ordered the little bear mc2 so i can use the Soloist on power amp mode, i like the results of that mode so much i am actually using it right now using the windows volume control since i have nothing else. I know i am losing bitrate but the bass slam is just more enjoyable on the HE6se.
Looking forward to experiencing the power amp mode with a proper hardware volume control 
Next is probably a Douk U2 Pro for me!
Btw @Pokrog, is this the one?
Also, a cheap coaxial cable such as this one is the way to go to connect it to my DAC which is a Schiit Modius?
I am wondering if coaxial will make a good difference as well, i think i2s is the best but i donāt have that option
I think Iāve seen the U2 pro for as low as $45 but yeah thatās it. That coax should work just fine.
I am having trouble understanding if a regular RCA cable can be used as coaxial. I have good RCA cables here but i have no idea about their impedanceā¦ Any thoughts?
i think coax is supposed to be 75 ohm. i think there are 50 ohm coax as well but i think 75 is more common. not sure what difference it makes though.
Regular RCA cable can be used in a pinch, is not ideal though since the lack of impedance causes signal reflections.
If memory serves:
SPDIF is 75Ī©
AES/EBU is 110Ī©
I should find a 75ohms then, no luck so farā¦