I know this is an old post and I'm not an expert in this hobby I can only share what I experienced. I owned a Stax SRM-006t and a pair of 507's. I purchased the H-03 and the M-10 and sold my Stax setup. First I didn't like them but after they broke in the KingSound floored me and sound better...

IMO the H3's are not harsh like some Stax phones and do not require a Tube amp.   Next for me is to purchase a SRM-323 or 727 and see if it is an improvement from the KingSound SS amp.

I wonder if the Stax SRM-323 would sound better? Has anyone tried this combo?

I 100% agree with you.  I picked up a KS KS-H3 with the solid state amp and to me it sounds better than my 507's with SRM-006T Stax setup.    I am sure the 07 and 09 and Stax are a different world.  Now I would like to try a top of the line solid state am with the H3'S.  I also find the KS more...

Just received my SR 507 and SRM 323 set up from Price Japan. Great deal, along with my 120-100 volt transformer from Amazon I saved $800. Initial impressions are super comfortable and first class all around. Thanks to this forum or I never would have known about these gems.

I just ordered the SR-507's with a 323 from Price Japan. I am not an expert and this is a new hobby for me, what I decided is why not go for one of the best and most unique setups from the start? I hope to enjoy this hobby for years to come and enjoy owning Stax 507's. The best I have enjoyed so...