What are your thoughts on the 887? I was thinking about going that exact same way as well but I liked the small real estate requirement of the SP200 and the possible future match with the M200. And, I didn't really want the mix/match look hoping to not have to sacrifice audio quality for look. I can blame my OCD on that. I am running a Aune X1S/X7S stack currently hoping to replace both with the SMSL products and have a healthy step up in sound quality.
Have had the 887 and SU-8 long enough now to give you my own impression. I have the interconnects and headphones all on XLR cables, with a USB inputting to the SU-8. I am absolutely loving the results. Mind you, I am coming from an Essence STX sound card - a very competent card as internal cards go, but the difference is apparent, as well it should be considering the time and money spent upgrading.
This forum was key in helping me make wise decisions - both in reading many reviews and comments, and in folk responding to a thread I started while in the process:
https://www.audiosciencereview.com/...hx-aaa-887-smsl-su-8-v2-topping-dx7-pro.9724/
The 887 is such a solid foundation, with enough power and flexibility that no headphones I can imagine purchasing would pose a challenge - high impedance, low impedance, IEMs, ha, bring them on. I had been a bit worried before actually listening due to some reviews I had read / watched. Opinions that the 887/789 is dry, clinical, flat, sterile, etc. and is best suited for reference analysis rather than listening for enjoyment.
Hogwash. It is exactly what the testing revealed, so I'll just quote Amir's conclusions:
"There is not one subjective flaw I can identify with this amplifier... I did not think it would be possible to build a mid-priced headphone amplifier and beat the Massdrop THX AAA 789. It is clear that the Monolith team managed to go against the tide and produce even a better headphone amplifier. Both subjectively and objectively, the "Monolith by Monoprice THX AAA Balanced Headphone Amplifier featuring THX AAA 887 Technology" (yes that is the official name) beats the Massdrop offering. Mind you, there is not much room left to squeeze one up there but they did. It is like beating the world record holder in Olympics.
Needless to say, it is my absolute pleasure to recommend the Monolith THX AAA Balanced headphone amplifier. It delighted me to see a company dedicated to absolute excellence and full transparency to our sources and content. This is a type of product you buy once and you are done. It made me happy just testing it!"
What more could be said
Edit: As to the new DAC from SMSL that will be an upgrade to the SU-8, I'll just have to wait for reviews and feature comparisons to know if I'd consider a replacement. The SU-8 is a darn good product.