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One price includes all related work, parts, and return shipping.  Just to be clear, this is an upgrade service where you send in your original Shure SM57 or SM58 (do not send other models, as I have not tested transformer compatibility yet, thanks).  


You will not believe the difference this makes, and we wanted to really get the process perfected before offering this service.  The classic SM57 has long been one of the most versatile and famous of 'desert island' microphones; known for doing many things acceptably, from snare drum to guitar amp cabinets.  The weakest link by far in the microphone is its output transformer; as the body and transducer are actually capable of delivery much more unrestricted, more dynamic, greater bandwidth, faster, richer, more open sound.  We carefully disassemble the microphone, setting aside the XLR connection, head, and thereby isolating the lower shell.  The generic output transformer is carefully 'boiled out' by softening the epoxy resin it is entombed within (the only viable non-destructive way of doing this, as we've learned), and the shell is sufficiently cleaned out using a drill press and various rotary cleaning tools.  We install AMI's amazing T58 transformer upgrade, designed by the late great Oliver Archut, and it is soldered in using silver solder and the best wiring.  We then fill the void back up to the same internal volume as before using parafin wax which is carefully heated up and cast into the shell to re-encase the transfomrer as before.  this method not only restore's the mic to its previous weight, mass, and internal volume; but is also reversible if ever required in the future, by using the same method I used to extract the previous transformer.  


This is a time consuming and costly process; but the modification is well worth it.  I can honestly say that the finished mic is almost sonically indistinguishable from my venerable original Sennheiser 421u4 dynamic microphones, which is one of my all time favorite mics.  What you'll notice more than anything is that the original transformer has sort of a plastic 'smearing' effect to the sound, and tends to roll off the upper top end and lower bottom end in addition to smearing transients and the somewhat nasally tonality.  All of that will be gone; and you'll be left with wide open dynamic rich sound.  It's been argued that the limiting factors of an SM57 are exactly what make it good at handling abusive SPL and capturing midrange instruments like snare and electric guitar so well, naturally rolling off some of the undesired bandwidth by virtue of their limitations.  It's a good argument; but I would also argue that this is incredible easy to do in the modern workstation, and of course we do band-limit those instruments most of the time.  Why do it twice, when this will only make issues of phase and fidelity worse?  I would argue that its very easy to scale these things back in the DAW, just as it is to add distortion and rob fidelity... but its damn near impossible to bring those things back if they were never captured well to begin with.  Try this approach, and I'm sure you'll agree.  And to boot, a modded SM57 not only costs less than a vintage 421; its infinitely more durable and easier to position into hard to reach spots like snare and toms.  


Don't forget to add a Gotham 3pin mic cable for the best possible sonic results.  

SM57/SM58 modification

6 Meter Gotham mic cable