I only check this site a few times a year, but I'll weigh in. Not sticking around tho.
My vote is for Hugo2.
It's 2023, only FPGA DACs matter. OEM DACs don't. If you listen to K-Pop, sure go OEM DAC. If you want serious listening, FPGA only.
So that narrows it down to Chord and dCS. For Chord, anything above a Hugo2 is too much power for IEMs. The TT2 has a resistor on the 3.5mm, 6.3mm output but that could possibly funk around with the Frequency so that pretty much rules out anything > Hugo2. The TT2 RCA OUT would be too much for IEMs without a resistor present. Also on Chord Summit-Fi threads, Hugo2 is mentioned many times to sound more like the DAVE so that's all the reference standard one would need. dCS has the same issue, too much power. Their target market are headphones.
For I, the RCA Output of the Hugo2 is the only way to go so Mojo2 is not going to cut it. I use a split Custom L+R cable so there's zero possibility of Crosstalk and Imaging is off the hook since it's perfect L and R separation. Think speakers. Perfect L + R separation, you don't braid L+R together for speakers. That would be wrong on so many levels so why make your IEMs suffer when you don't need the convenience.
This allows me to use quality connectors such as WBT. Small connectors are usually junk quality and because the soldering is so close together, Crosstalk is plausible. WBT runs $100k speakers with ease and provide superb transient response. WBT clamps really well and one need to twist tight to clamp.
The issue with Hugo2 is portability. If, as I understand, you waived portable as a requirement.
I'll post a diagram of my chain, but I need to give a summary to get a better understanding of the chain.
There's no precedence for my chain as it's a variation of dCS and Chord philosophy chain. dCS combines precision clocks for accuracy to pair with their FPGA DAC. I do the same but use State Of The Art (SOTA) clocks for accuracy to pair with Chord FPGA DAC because I like to stay within the CIEM realm only. It's too easy to go crazy as those dCS users spend 6 digits on their chain. Speaker users are even worse. I'm fortunate to stay within a 'Goldilocks Zone' with performance on par with the best headphone and speaker chains but at a decent value due to experience in this hobby. I don't like the variance of headphones and speakers so those would never interest so I'm quite ecstatic with my chain.
^^ As you can see dCS FPGA DACs have master clocks already, but still can be improved upon with the source.
^^^ I easily get the lifelike and 3D sound, it's euphoric. External clocking.
Here's some recent post from dCS Bartok. I get the following qualities too as dCS clock + dac users. I never thought about my chain more electro-stat-like, but that describes it pretty well:
Listening through TOSLINK, and comparing it to my vanilla ethernet connection from my home router has been pretty fun, so far.
TOSLINK sounds cleaner, more "ordered", and has a dryer, "just the facts" kind of character. Background is blacker. Makes the Susvara sounds more electro-stat-like.
The quality of the treble and bass are perceptibly different. Treble is smoother, and bass sounds "truer" and runs deeper.
It also sounds leaner, without question (and which is most pronounced with my speaker setup).
https://www.head-fi.org/threads/dcs-bartok.901647/post-17593731
Clocks can get quite expensive. "External clocking makes a big difference in music presentation on dCS gear" or in my case Chord gear. No dCS DAC user can run a DAC alone, 95% buy a dCS clock along with their dCS DAC. I can't run a Hugo2 by itself, I need a State of the Art Clock source. Similar to 95% of dCS users whom would never dream of just using their dCS FPGA DAC alone.
So you used a 24.500€ Vivaldi clock with the non Apex Bartok?
Was the benefit worth it over the Lina or Rossini clocks?
It’s a less common configuration, but yes. With great results. I never auditioned Rossini, so I can not say whether Rossini and clock would have been much better. One dCS community member heard a comparison with Bartók + Vivaldi clock vs. Rossini and said the Rossini only pulled ahead with the Rossini clock, not alone.
I purchased both DAC and clock at the same time and have not tried Rossini or Lina clock (which didn’t exist at the time). I came from Naim ND555 and was looking for an upgrade somewhat above that price point. External clocking makes a big difference in music presentation on dCS gear. Hence the choice of Vivaldi clock. I wanted to enter at the lower end of the DACs, because I could not know how much I will like the experience over time. How different the clocks sound? Unfortunately no idea. I can only tell you that plugging in the Black Cat Trøn clock cables for Vivaldi dropped my jaw, the power cord makes a difference and resonance control. Another dCS owner subsequently bought the Mini Trøn for his Rossini and his jaw dropped as well. So I would assume, that clock precision and surrounding components inside the box are quite noticeable too.
https://www.head-fi.org/threads/dcs-bartok.901647/post-17593731
Just wanted to give some background on clock+dac before presenting my chain to give a better understanding of what is going on:
I'm running arguably the world's best Toslink chain independent of DAC / Transducers / Etc. I am running the World's Best Passive Power Supply for Audio. No Mains.
So it is as close to a dCS chain as possible in 2023 that you can get with CIEMs without spending six digits. It certainly sounds like six digits because I'm going crazy procuring the expensive CD media and moving on from fiddling with Audio gear. So since dCS doesn't cater to IEMs, I made my own variation of dCS Clock + FPGA DAC.
For my future Transportable project, I'm hoping to combine a Steam Deck OLED with a Hugo2. Since I only run Audiophile OS and solid core USB cable, it's a possible project. Without those two requirements, it's a deal breaker.
There's too much Warm on Warm crime going on in the IEM world. My chain is perfectly Flat Neutral as my GOAT CIEM cable with WBT that's perfect Flat neutral as well. So many Chains these days are just Warm Source, Warm cable and Warm IEMs. Disgusting. But they are for K-Pop use so does it really matter.
So my vote is for Hugo2. With Hugo3 a few years away, it will be an easy upgrade to plug into the chain.