Mike Rivers wrote:

One spec that's rarely published is the total amount of current
available from the phantom supply. It doesn't seem like it should be
a big deal, and it isn't if there's a real power supply for the mics,
but often this is a place where manufacturers save money.

When the powering is inadequate, several different problems may
occur depending on the microphone's specific circuitry. Some of
these problems, such as lower maximum output voltage (which
corresponds to a lower maximum sound level), could ruin a live
recording without necessarily being obvious in a rehearsal or
a bench test.

That's why there are standards in audio. End users shouldn't have to
worry about details such as the exact resistance between the DC supply
and pins 2 and 3 of the XLR socket. But many manufacturers, especially
in the United States, seem neither to know nor care about standards.
This is a "chicken and egg" problem since the only way to hold them
to account would be if the customers were better informed--but again
the whole point of having the standards is so that customers can focus
on what sounds good instead of all these implementation details.

Some people feel that modern transformerless condenser microphones
don't sound as good to them as mikes made in the 1970s. But the
early 48 Volt phantom-powered FET microphones generally only drew
1/2 or 3/4 mA, while the ones made today draw 5 - 10 times as much
current or more, are often 5 - 10 dB more sensitive, and can handle
maybe 10 dB higher SPL. A mixer or preamp designed in the early
1970s may be compatible with a U 87 or a KM 84, but not with a
TLM 103 when someone is screaming into it, or when a percussionist
or pianist is playing a healthy, normal fortissimo.

The thing is, our ears can only tell us that something is wrong if we
know what it's supposed to sound like in the first place. When I see
people posting opinions of certain microphones, I sometimes wonder if
they've ever checked the phantom powering, the impedance and overload
point of the preamp or mixer input that they based their opinion on.
Those things are rarely specified in clear terms and they are never
mentioned in published equipment reviews--though that information is
absolutely essential for us to know what's compatible with what else.

--best regards