Warmth, clarity, openess

[mikehalloran]

Although the links to the article and instructions are gone, someone decided to build and sell an inexpensive Impedance converter for the SM57/58 as suggested. Requires a 1–3 dB preamp boost to match level for a 57/58; 25 dB or so with an SM7.
https://reverb.com/item/1402020

Still easy to make by buying a barrel connector and wiring an 850 Ohm resister in parallel.

These work by lowering the impedance that the microphone sees. Loading it properly lessens overring distortion and proximity effect while smoothing out the top end and increasing transient response.

Hi-hats and cymbals sound natural and a 57 becomes a useful studio mic for some voices. If looking for the crunch these exhibit on toms and amplifiers, best to leave these converters out of the signal chain.