The rascals..
Actually I noticed it when I borrowed two mics that have diods on them that light up when they are powered (forgot their names now), second mic plugged in and diods went off..
Those are called LEDs (light emitting diodes)
Another question: budget two channel microphone preamplifier (or two one-channel ones)?
I've owned a focusrite green 1, which was lovely, and which is 'budget' as second hand nowadays.
Unfortunately, here we have not too many choices. Most of the budget ones to me sound all the same--dull and grainy.
IMO, there are only two noticable exceptions. First, funny, but actually aforementioned AudioBuddy is one of the cheapest and in fact, is very usable one

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This is true its phantom power sucks big time, but the trick is to use it with outboard one. There are plenty of those for cheap (around $25-40 new on evil bay).
Then there is ART Digital MPA Gold which at about $275 new from ebay might seem not that budget, but this guy has a digital/analog converter, so by itself it is already a major step up, compare to feeding your analog audio into computer. Compare to a stereo pair of Studio Projects VTB1 this one seems to be a better option and better bang for your $$$.
And then there is Mini Me, which I'd consider the entry level to more serious recording, but it is already out of reach of most of folks here.
And of course, we have Great River (one channel), John Hardy, etc.. Not cheap, but you know what you pay for.
And I don't even get into tube stuff

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Best, M
P.S. Oh yeah, if you are on a real budget and not looking for some fancy-shmancy stuff and highest quality, then aformentioned Zoom H4 would be also a good choice.
Use it as it is or with external microphones if you can afford them.