The fact that this item doesn't state whether or not Magical Locks are unaffected makes for a convenient loophole in its abilities, I think. 

Quote from NPC_Mimic >>

The fact that this item doesn't state whether or not Magical Locks are unaffected makes for a convenient loophole in its abilities, I think. 

If you are referring to the arcane lock spell, yeah it would be up to DM ruling, but I think I would rule that the chime of opening is similar to the knock spell, except it emits a chiming sound instead of a loud knock. So it doesn't bring down the arcane lock permanently, but it suppresses it for 10 minutes.

Personally, I would give the restriction, that the lock has to be material. Arcane Lock goes under the category effect for me, personally. There's not an actual lock there, the door is simply "locked"/unopenable. However, a magical lock with a physical appearance would open just as easily as any other.

I want to collect like a hundred of these and through them off of a tall building in a city just to see if everything in the local area would suddenly unlock.

New item idea: Chime of Nopening. Works exactly like a Chime of Opening but when the door opens, a swarm of creepy crawlies scurries out and scatters. Roll 1d6:

1. Spiders
2. Snakes
3. Centipedes
4. Earwigs
5. Cockroaches
6. All of the above

All creatures witnessing this must make a DC12 wisdom save or be frightened until the end of their next turn.

People often complain that this item can be over powering for story. So what, it can actually help them feel like progressing in an area, rather than them missing out due to bad rolls which can happen. If you want to use it but think it still it’s too much, you can adjust the charges so they use it rarely. How often do you think people leave fully charged chimes of openings around? Also if a NPC is toting this around they have most likely used it.

I'm gonna make an adventure where the players get one of these and have to open a door with 11 locks! I'll have to make rogues illegal.

I got killed by a rabid Jabberwock and tried to escape with this through 11 locked doors so I died rip me

Basically an item that has a Cantrip Thaumaturgy - Spells - D&D Beyond (dndbeyond.com), but slightly better if the DM allows it. Needs to be a un/common item pending RAW.