This time, our patient is a cheapo Chinese Ribbon Mic.
Model is t-Bone RB500.
Sold (I believe) exclusively by Thomann. Basically, same as APEX 210, NADY RSM-2... etc. Same Chinese factory, same small fellas at the assembly line, just different branding. Or at least that is what Google says.....
Тhe RB500 is not a bad mic at all. It has a deep though rather boomy and boxy sound. What were the suspected production faults: el cheapo trannie and thick ribbon. I ordered a new Lundahl LL2912 transformer and a piece of 2,5 microns Alu foil. After the goods arrived, the patient was deployed on the "disassembly line", so to say :)
Naked patient:
First pleasant surprise. The old trannie is protected in a well made steel "capsule". Goodie-goodie. Well done, PRC!
Old and new trannie and "capsule":
New transformer in place. Check which wire goes where. In best case of a mistake, the mic will be out of phase, which is not such a big issue. In the worst case, you will get no sound. That means you have reversed the transformer coils and you decrease the sound level instead of amplifying it.
Now comes the tricky part. Disassemble the mesh on one side of the ribbon. Be gentle and careful. Do not cough or sneeze. That would be enough. Forget about wearing masks or other such b**shit. Just be careful, slow and precise in your movements. Here is how the old ribbon looks like. Actually, pretty good job. Nice corrugation, no sag!
Measure the width of the ribbon. Cut a piece with same width, but longer (remember the corrugations will shorten its final length). Cut on a massive and solid pad, with a BRAND NEW blade. I repeat: brand new. Cut applying pressure, in one stable run:
There is more than one way to corrugate the ribbon. This is a toothpaste crimper, sold in the net (Ali express) for 2-3 EUR, delivered. Worked fine for me...
Finally, install the new ribbon. Basically, fix one end (gently) then pull the other until ribbon is horizontal. That will do. Then fix lightly the second end:
At the end, grab your multimeter. Check that ribbon does not touch magnets. Then measure resistance between ends. Should be from 0,7 to 1,5 Ohms. Any figure in between is acceptable. If all is OK, plug mic in the preamp and presto.... start playing your guitar :)
Check for yourself a before-and-after sound sample :)