not it amp-board of sony ecm 957 pro , in the sony ecm-ms 957 , but the capsules of the sony ecm 957 pro , in the sony ecm-ms 957 mic and you get this sound , listen here ,
https://www.youtube.com/watch?v=E1I4soP-48Monly he is rebuild , the capsules is on headband , further, there is nothing changes , and works on 1,5 volt it beste , I has use 9 volt , but was not better ,
here Chris Bergson Band live at the club the Q bus city Leiden holland 2014 06 10, with the same mic,
https://www.youtube.com/watch?v=qXPkffWAdQk , it works on 1,5 volts , but the sound of both is edit ,
is recorded on large distance ,I sits with back to rear wall of the concert room , why I sits there is for the camera , I sits there higher and look on this way over the people , but I get on this large distance good sound , only with this mic , the corpse or I for the podium stands , and that is not so , it is on large distance recorded .
I hope that it help you sir
Ane