Respectfully, I'd consider another approach. I've had a different experience with the 90D, and honestly, the preamps are fine if you dont push them. Instead of just any mic, you basically need something with an internal preamp to keep the camera noise floor low.

• Deity V-Mic D3 Pro: This is the safest pick under $150. It has a dedicated analog gain knob. You can set your 90D manual audio level very low and use the mic to boost the signal. It sounds way cleaner and handles wind decently with the foam, tho you might want a furry windjammer for vlogs.
• Rode VideoMic GO II: A solid, lighter alternative. It is basically plug-and-play, but you lose that fine-tuned manual gain control. Id go with the Deity cuz it gives you more technical control. Just be careful with those battery levels before a shoot!!

Just sharing my experience: I went through this exact same struggle last year with my 90D!! I lowkey thought something was wrong with my camera until I realized how the internal preamps actually work. Basically, you want the camera to do as little work as possible to avoid that nasty floor noise. I learned that if I turned the camera gain down to almost zero and used a mic with a higher output, the audio became AMAZINGly clear! I started with a super cheap mic but the wind noise was literally unbearable. I eventually picked up the Rode VideoMic GO II and it totally changed my vlogging setup. It fits the hot shoe perfectly and it's so lightweight you barely notice it's there. The coolest part is that it doesn't even need a battery, yet it's way louder than those tiny button-mics. I also realized that if you're filming outdoors, the standard foam covers basically do nothing. I had to invest in a Rode WS12 Deluxe Windshield which is like a fuzzy deadcat - it made such a huge difference for my windy beach vlogs!! Seriously, dont skip the wind protection if you're outside. It's a bit of a learning curve to get the levels right—I actually clipped my audio a bunch of times at first—so definitely do a quick test every time you swap locations. It's a fantastic setup for under $150 if you're careful with it. Hope that helps! peace

yo, i feel u. honestly, i've been using the 90D for about a year and the audio is the one thing that highkey keeps disappointing me. i mean, the camera is great but the internal preamps are just not as good as i expected. i started out with this cheap little plastic mic because it was light and fit the hot shoe perfectly, but man, it was a disaster. the signal-to-noise ratio was terrible and i had to crank the camera gain so high that the background hiss was basically louder than my voice!! so yeah, i eventually switched to a more expensive setup that uses an internal battery. comparing the two was like night and day. the first one i tried relied on plug-in power from the camera, which just didnt work well for the 90D. the second one—the one i have now—has a dedicated +20dB boost switch. that let me turn the camera's internal gain almost all the way down to like one or two clicks above zero, which literally saved my audio quality. but even then, i've had issues. the wind protection on the one i got is pretty weak... i had to buy a separate deadcat furry cover because the foam one it came with did nothing in a light breeze. also, i found that if you dont have a good shock mount, youre gonna hear every single click when the lens tries to autofocus. it's kinda annoying tbh. id say definitely look for something with its own power source and a really soft mount, otherwise you might end up disappointed like i was. gl!