Hi - Talked to my friend last night who owns a DA5.
He will send instructions to adjust bias at a higher setting shortly, that by the way were provided by Jadis (so no vudu-like mods in this case).
He told me that it is auto-bias and not (????) and the trick resides in some passive controlers within the DA5 circuit (whatever that means...), anyway.. I will get the instructions from him later and will post it for your info.
Fernando