I got information from Suyama San , that The Upgrade fir My MH 335 DW is not available yet , he has not confirm when .
If the upgrade available , he want anouce through his website
I hope can upgrade very soon , because the SQ different quiet significant
Below is copy from Suyama San :
I’m sorry but the upgrade service isn’t even available yet. It’s not that we’re not releasing it yet, it’s that it isn’t even available to anyone. For that reason we cannot upgrade your custom earphone now.
When it does become available we will announce it on our site. You will have to sit tight. When it is available it will be available through application process from the distributor through which you purchased your earphones.