I own both Serene and Serenata. Serenata is 'backwards' compatible with Serene as far as EarSet1 Mobile and EarSet2 goes. That's it. EarSet3 Serenata model is very specific to itself. In any case, that particular variant of EarSet3 is now obsolete anyhow. EarSet3i has taken its place now, which is far better in design and I'd say sound as well (the bass response seems to be ritcher than A8's). As fas as adaptor is concerned, you're out of luck my friend.... No such thing exists.
When it comes to sound, there IS not other device on this planet that would come as close to the sound quality output as Serenata has. It sucks for texting, but it was not ment for that and if you can accept that fact, it's the greatest mobile telephone/music player ever made on Earth. I'm tempted to call this device a portable set of BeoLab 5's. But that's just me...
Oakley out.