Since we have a few discussion on the modding in the last page or so, let me chime in with my experience. I have the AK240SS for almost one and a half year, and I also own the AK380CU for about four months. So I have the opportunity to compare very closely side by side and AB the two Daps and in some instances track for track and notes for notes. First of all they are very different daps with different sound signature. Before I own the 380 I told myself I don't need the 380 because it is a sidegrade and not an upgrade and I was very very happy with my SS. I really enjoy the SS's crisp, clean, fast, neutral signature. So much so that after I bought the 380CU I still don't want to let go of the SS. After I own the 380CU for awhile, I became familiar with the CU, and yes the CU's signature is more spacious, warmer, a little rounder, better bass and I enjoyed these features a lot.
Then in my search to always find a way to improve things better, I sent my SS in for the RW mod and I received the RWAK 240SS back for couple of weeks now. I burn in the caps for about 50 hours or so. Guess what, upon listening to the modded SS, I felt like I have lost my 240SS. The sparkle is gone. Yes, everything they said on the website is true., there is more bass, tighter bass, seem like the mid and the high is smoother also, but what makes me like about the240SS is gone. The sparkle, the slightly bright but extremely clean signature is changed to a warmer, smoother, with snappier bass signature. You can say it is an up grade but I find myself missing the old signature also. It is like everything in audio, if you like the Stax 009 you have to accept the thin bass also because once you add the bass to it, you may loose that fine quality. Or the difference between JH13 and JH16. It is still a very very good dap but I wasn't sure if I want to loose that signature. Now I felt like I have a great dap (RWAK240SS) and I have an upgraded dap (380cu) of the same signature. Originally I was going to send in my CU after my RW SS is done. Now I am not sure at all. I enjoy my CU now, I of course want to improve it further but I worry it may change the signature that I like. With the added bass on my 240, I also felt like the airiness is reduced. At least that is my impression now, I will updated if there is any revision in the future.
By the way, I did some hard comparison between the RWAK240ss and my 380CU in the bass department using the same song and only switching my balance Therium/U12 between the two players back and forth a few times. Yes, the RW240 did have a significant improvement in the bass department but it is still ever so slightly not quite at the level of the cu. The fact that it is approaching the level of the CU is a strong statement of what the mod can do,and for those people that think the 240 is a little dry and bass thin and do not care about changing the unique signature of the 240, the RW mod is a great way to go. I would like to have someone that did the RW mod on their CU share their impression. Did they feel like it was an Improvement without altering the original signature? If so what was improved?