One of my favourite spots for music gear. For one, being just a quick walk north of College Station, it's easily accessible coming from any direction of town.
The owner Jasbir has always been accommodating, including in the past ordering in things he didn't have in stock. More impressively, even if it isn't listed on the website, he might just have the what you're looking for. I needed a new turntable stylus and was impressed to find he had older models in stock that otherwise are pretty damn hard to find without special ordering.
Prices are competitive if not better than most of the other main players in the Toronto musical instrument scene. Some stores seem more specialized, but as a one stop shop Metro Sound has served me well, so I'm a fan and recommend checking this place out for your assorted musical gear needs too.