Ok, just got the Solitaire T.
@angelom I'd say they sound pretty good to me out of the box. Not the same soundstage as the IO-12 at all, but they sound quite nice. Comfort wise, they seem to work for me, but I'll know more after I spend the day with them.
The soundstage is likely the only area where the Solitaire T concedes to the IO-12's, but in all other aspects, sonically the T are sublime for utterly natural sonics, passive wired and wireless.
@angelom has fantastic insight to sonic qualities, and the IO-12 do have their own addictive sonic signature according to his experience.
I have smaller ears so comfort and ergonomics of the Solitaire T are perfect for me. It helps that my experience with the Meze 99 Classics oval earpads helped me adjust to the (smaller) Solitaire T earpads too.
On the call side, the mic seems fine. The 2.5mm port works well for a boom mic when I want to be wired. The lack of sidetone is disappointing, and I don't think that conversation mode is a good substitute for it because it lowers the volume a decent amount.
I never needed an external mic for my Solitaire T when it comes to phone calls, but gaming is one area I wanted to explore.
Sadly, due to Sony's deliberate limitations for the PS5, it's a major hassle to get normal Bluetooth headphones to work with the console without using more accessories, so I just use official gaming headsets when I was game with friends.
Sidetone function has never been an interest of mine, and I never had a use case for it, which also explains how few wireless cans I've been interested have not featured them.
That said, I'd love if T+A could update both the Solitaire T and companion app to potentially add this feature, and allow users to change the Assistant button on the right earcup to a user choice, such as sidetone.
I don't think sidetone is a deal breaker feature for many, but of course if it is something required, their are cans that offer it.
Maybe in your case you could consider a cheap pair of wireless earbuds with sidetone just to have that feature for now, alongside your pair of Solitaire T?
I get a lot of static pops, not quite as bad as the Bose QC45/2023, but when stopping or skipping tracks, or switching modes, there are occasional pops that aren't pleasant.
Have you noticed any of the popping I was describing? It happens quite often.. I play a track for a while, then pause it and it'll crackle in the right ear. Play again, crackles again.
I have only ever heard pops if I overload my Solitaire T at high volume in passive balanced mode with my FiiO M17 (with this DAP set to DC input and Enhanced Over Ear Mode); that's when I know I'm listening far too loud. Blame the effortless scaling of the cans' addictive naturalness ha ha!
However, I have never had skipping or pops when using any audio apps, wireless or wired, to the Solitaire T.
Unless you can troubleshoot your source device (updates, delete cache, etc), perhaps consider contacting your dealer and request a swap to another pair.
Of course, please troubleshoot as much as you can first, maybe use another device to be on the safe side.
I'm still debating an amp for them. I'm leaning towards the Schiit Hel+, but the Moda 2 came across my radar too. I'd still prefer something w/ a mic input for my desk, and portable doesn't matter for me. I'd want something that'd make these sound good, but I don't want to drop a lot of $. Moda 2 is probably the most I'd spend. Compact is good too for my desk. Any suggestions?
This is a mindfield; we have an overflooded market of high quality amps and DAC's everywhere.
@WDitters is 100% correct, JDS Labs are king for sonic quality, objective measurements, and exceptional value. They are not the last word in sonic quality, but objectively, what any JDS Labs Atom amp version offers is astounding. It will be more than sufficient to power the Solitaire T.
Ditto your own consideration of Hel+ or Moda 2 (Verza Moda?).
Topping A50s is another powerful and affordable option too.
Or consider the recent Astell & Kern PA10, a portable amp (Class A) but no DAC.
Another recommendation is Chord Mojo 2 (single-ended, and wireless with Poly 2). This should also suffice.
If you want to use your phone as source, the FiiO BTR7 dongle is great too, with almost latest Bluetooth spec and SE + balanced outputs.
DAP's is crazy complicated to get into, but FiiO M15s is a great start imo.
There are a lot of options, so demo where you can, and consider features, benefits, lifestyle needs, and sonic quality to pair with your Solitaire T.
Hope this helps!