Osie today mounted each of the two transformers into a small Bud Box, with XLR panel mount jacks on either end for I/O.
My plan had been for the end of a 57/58/what-have-you to just plug straight into the box itself, but I forgot that the microphone body was too big in diameter for that to happen. So we just got the very shortest mic cable we could find, barely longer than the two connectors themselves.
I haven't yet had time to do a proper test with instruments and voices, but I couldn't stand waiting to hear this, so I just perfrormed a very simple, non-scientific, uncontrolled "Voice In The Control Room" test.
I took two SM-57's, versions purchased at the same exact time (about 1984). One of these was totally stock. The other one is the one from which I had previously removed the Shure transformer. So ideally, as many variables as possible for such a quick test were eliminated.
I spoke a simple "test" phrase into each microphone, run through the same cable into the same API 512c, direct into Protools through Apogee AD-16x. I recorded the phrase twice, once with each microphone, with my lips just almost touching the capsule end. This of course put me into proximity effect, but if one were speaking or singing through such a microphone, that's what one usually would do.
Here are the results:
The new AMI seemed to have a slight bit more volume overall, but of course, that could possibly be attributed to my speaking voice variance between the two recordings. But I did make every effort to minimise this.
The stock Shure transformer version was more strident in the upper midrange and "sibilance" areas, and not in a pleasant way. This is one of the things that I often dislike in a 57, that almost artificial "twang" that often seems to happen.
The AMI transformer did not exhibit this effect nearly so much. The AMI in fact had a noticeably smoother, rounder quality. The lows were also more pronounced, so that may have actually been covering up any upper mid stridency a bit as well. But the "extra lows" were not too much so, just fuller and more pleasing to the ear.
The AMI had a much more pleasing sound on "s's" and uncomfortable sibilance was reduced from what the stock trans exhibited.
Overall I would give the new trans a quick thumbs up.
But there is obviously a lot more testing to do, and I intend to get to that in the next few days.
For now, that's the quick and dirty 25