Final answer:
The failed piece of studio gear that Magic Alex built for the new Apple studio was the mixing console.
Step-by-step explanation:
The failed piece of studio gear that Magic Alex built for the new Apple studio was the Mixing console. The mixing console is a device used to combine and control audio signals in a recording studio. Magic Alex, also known as Alexis Mardas, claimed to have built a revolutionary mixing console for Apple, but it turned out to be a non-functional and poorly constructed piece of equipment.