New user here, thought I'd jump in and share my experience of the SU-9! After prevaricating for some time, having seen glowing reviews and reports I went ahead and finally ordered my SU-9 around the middle of May - as I'm sure many other people will have done since it hit the market. Although I'm in UK, I ordered mine from Audiophonics in France; I've used them before several times and their overall service and support is excellent. But although it was cheaper buying from Audiophonics I forgot about recent 'Brexit' changes around customs, duties and so forth and ended up having to pay £70-odd VAT & expenses to get it released! Doh!
Whilst eagerly awaiting delivery, I stumbled across this thread regards this (relatively) newly identified problem - bummer! Should I have gone for a different DAC I wondered?!
Anyway, received the SU-9 around a week or so ago and I must say it sounds much 'fuller' than my previous DAC (Khadas Tone Board), especially the bass (more pronounced but not 'boomy' at all) and overall a very expansive sound; all in all I'm suitably impressed. I don't notice any obvious deterioration in sound quality - but as has been previously mentioned on this thread the 'problem' may or may not be audible to the average user, and without a 'good' unit to compare with or expensive test equipment I probably wouldn't be able to tell anyway. I must stress I don't profess to be any sort of out-and-out 'audiophile'; I simply like listening to good sounding music! My version is the same as identified earlier in this thread by the way.
So, following on from the more recent posts here I contacted Audiophonics to make them aware of the 'issue'; needless to say they were not aware of any reported problem with the SU-9. In less than one day (did I mention their support is excellent?!) they have confirmed they've been in touch with the manufacturer (Shenzhenaudio?) and their last response to me is (quote): "I have contacted manufacturer and i wait to know how to process for updating unit of our customers. I inform you when they give me the solution."
So with a bit of luck it looks like I may be able to get mine sorted out (maybe!); how or when still not sure just yet. I share this experience to offer some hope to all you fellow SU-9 users out there that you might manage to get a result as well sooner rather than later, especially if distributers/agents are going to be able to assist and step up to the plate as well.
As has been mentioned several times throughout this thread; we all accept that sometimes these sort of 'problems' happen, that's just life; it's how the situation is dealt with and resolved is what really matters.
All else aside, to my aging ears the SU-9 on my set-up sounds simply wonderful - at the end of the day that's all that really matters I guess!
Sorry about the long post - happy listening to all!