When trying to use /setblock to set comparators or repeaters it says that there is no such block with that name. This can be replicated by either typing in the command to set the comparator or repeater into the chat bar or by typing it into a command block. I'm not sure if this also happens when in multiplayer.
It's unpowered_comparator / unpowered_repeater for the block.
comparator / repeater is the item.