So it arrived early today, sonically it didn't make any difference or distortion thankfully, and construction-wise it's decent, nothing to write home about but is solid. There isn't anything problematic and the connections are solid and don't wobble as far as I can tell through normal use. Length-wise it's unfortunately bit longer than the Acoustune one I believe, and it does cause the ear hook parts to kind of overextend a bit, which through normal use should be no problem, but if you like sleeping with your IEM I can forsee this might cause some issue since it's an extra segment of connection...
I swapped between the cable my Diva came with (Effect Audio copper cable) and my sterling silver mmcx cable (Audiotrak RE:cable SR3)'s original connector length with the converter connected, and tried listening to a few songs on my DAP (Cowon Plenue 1), as well as some youtube videos of First Take songs, and noted that there is a very very minimal amount of positive difference between the two cables. (I only tested with the middle bass switch because that's the setting I use and am most used to.)
For bass response, original copper cable has a slightly better bass impact but cloudier rumble, while the silver cable tightened the bass rumble up a little bit, at the cost of losing a tiny bit of impact, but not enough where you'd miss it. Sometimes depending on the song the bass could be a little bit cloudy on the Diva so the silver cable can help with that to some degree, but again, it's a very subtle difference, so I wouldn't really recommend buying a silver cable just for that unless you already have one on hand just to try the difference. For example, when I was listening to the First Take song linked below, in the beginning when the bass started kicking in the rumble on the copper cable would be a tiny bit rumblier than the silver cable, and it could be a little distracting, though the vocal cuts through it pretty easily still with either cable.
Mids and vocals are about the same for both cables, I feel like in terms of sound details the silver cable has a bit tighter sound focus than the copper one which seems to be just a tiny bit blurrier, which I previously had a similar experience with my Campfire Andromeda. But honestly it's not that big of a difference overall, and in Diva's case I think I actually prefer the copper cable in terms of vocals for some reason... Spanish Harlem and Manha De Carnaval didn't sound all that different to me with either cables, and I don't really have a preference on which one I like better in terms of mids/vocals. I might even lean more towards the copper cable for some songs because it sounded less sterile than the silver cable.
Treble is probably where the two cables have the most difference at, where the treble is a bit more elevated on the silver cable vs then copper one, however in Diva's case this might actually be a detriment, because some songs that were at the edge of sounding too sibilant on the copper cable now sounds too damn sibilant on the silver cable. For example the song by Juju (I can't type Japanese but it's in the picture) on the copper cable you can tell the song has a bit of sibilance to it but it's not that bad yet, but on the silver cable it's obvious as day and the high notes or her voice all have that sizzling ssssss after it, which I don't really like. While this isn't an issue with songs that are well recorded and not sibilant, taking into account that not all songs are recorded equally and depending on the type of music people like there's a high chance they have a library full of songs with bit of sibilance to it, I feel like the copper cable would be a better fit for the Diva just for this reason alone.
So in conclusion converters work but are a bit long, I'd say just get the Acoustune one instead of the amazon one I found because the Acoustune one is shorter, and based on what
@-rowan- said the quality is really good so might as well get that one instead. It'll allow you to use any other cables you have on hand for the Diva which is nice.
In terms of difference of sound between silver and copper cable on the Diva, I'd say just stick with copper cable. The difference in the bass and mids aren't enough to offset the sibilance difference between then two, which would bother you more than just a tiny fraction bit of tightening on the bass/mids overall. Diva's sound is already pretty clean to begin with so there's really no point in tightening it even more. I'd probably even shy away from silver plated copper cables too for this matter, and just stick with nicely made copper cables that fits your needs, or just use the one it comes with which is actually a really nice cable lol.
Glad I bought this converter regardless though because now I don't need to shell out that $400 for that silver pentaconn cable XDDD...