Originally Posted by monkeyxx
so where's the difference, the windscreen as hypothesized?
I second that question. It's clear that the windscreen is not acoustically transparent on the R144 as evidenced by the fact the sound is noticeably brighter on the rear than the front. That, along with the fact the R40 sounds the same on both sides (or extremely close) makes me believe that the windscreen was DEFINITELY changed in the R40. There isn't much else in the mic - ribbon motor, transformer, windscreen. If the ribbon and transformer are the same that leaves...
Maybe I'll get up the guts to completely expose the ribbons and retest. That might shed some light on the matter.
May I ask how you can be certain that the transformers are exactly the same? I find that stuff from China changes all the time, and there are no markings that I can find on the transformer (I opened the case to look at the transformers but not the ribbons). It seems possible that the transformer could have been improved without "prior notice". I will admit the specs are quoted as being the same for both mics and I'm at a loss to explain the increased hiss in the R144. But unless there is information from the manufacturer to the contrary, I don't think a design modification of the transformer can be absolutely ruled out. They look the same, but the same case mold for the mic was used so they had to be shaped the same to fit and I'm sure they used the same case for the xfmr. But it's relatively easy to change the number and ratio of the windings, core material, etc. and have the transformer look exactly the same. Even if the DC resistance is the same, unless you perform AC tests on the transformer, or MXL says they didn't change the design, you just can't be certain it's the same. It's not nearly as easy to make minor modifications to a ribbon. Retooling isn't required to change the design and construction of a transformer, just readjustment of the winding machines. I would imagine that making a change to the ribbon motor would involve a lot more investment, which is probably why there are only a handful of cheap Chinese ribbon motors on the market. The differences between mics using the same ribbon motor are in the way the ribbons are protected and the transformer designs, at least to the best of my knowledge.
I vote it's the windscreen. I also base that on the posts concerning removing it to improve the mic.
But I still don't get the hiss. I'm running my tests again right now to be absolutely certain.