Sennheiser MD441 U3 and Electro-Voice 635a with Western Electric D163851 transformer

Signal path:


Male singing voice - mic - (Pleiades 130Ω,40mH LC gentle filter see text) - WE D163851 1:2 step up transformer - Sony TC-D5 Pro at XLR mic in - Sennheiser HD580


Inserting a good quality 1:2 transformer effectively doubles the turn ratio of the mic input transformer of a preamp. Not only this but removes heavy bass or treble.


It may make therefore the mic sound 2 to 4 times for example as big.


The MD441 U3 directly connected to Sony sounds almost unusable for close singing voice. Too bass heavy and low output. Inserting the WE transformer in the chain the signal increases. The mic can be used at 12in-24in with much less bass heaviness. More presence. There was some hiss.


The Pleides R,L filter was connected just after the mic. The MD441 U3 could be used at 1-3in with natural no bass heaviness sound. Hiss was much less as mic was very close.


Directly connecting the MD441 U3 to the Pleiades V6 2DV4 Nuvistor operating at 1.3V for heaters and plate (anode) should sound much better if acoustic memory is correct. There was some hiss too. See previous posts.


The Electro-Voice 635a sounded much better too. At times 4x as big. There was still some bass heaviness. But much less so. And less high frequency exaggeration.


So far the mic that benefits more is the Sennheser MD211 N, see previous post.