Topping A90 supposedly lacks ESD protection?

[redstang]

Balanced is more immune to unwanted signals (external) induced in cables and for ground loops. That is the main reason for using balanced cables.

And that's for interconnects, not headphone cables. A true balanced interconnect has 3 wires and sends + on one, - (inverse) on the second, plus the ground. "Balanced" headphone cables just give each speaker their own negative wire. This is an interesting write up on the topic:

Audio Myth - Balanced Headphone Amplifiers are Better

This Myth Goes Something Like This: "Balanced headphone amplifiers are better." "If balanced line-level connections work well, balanced headphone outputs should also work well." We disagree! Benchmark does not offer voltage-balanced headphone outputs on any of its products. The reason for this...

benchmarkmedia.com

 

[danity_project]

I just had my Topping A90 blow the right channel due to static electricity. I pulled a blanket over my legs and it sounded like my right headphone exploded. Now that channel doesn't work, and has weird fuzzy noises when I turn the volume knob towards the bottom.

(note - this was with a balanced headphone connection)

 

[restorer-john]

I just had my Topping A90 blow the right channel due to static electricity. I pulled a blanket over my legs and it sounded like my right headphone exploded. Now that channel doesn't work, and has weird fuzzy noises when I turn the volume knob towards the bottom.

(note - this was with a balanced headphone connection)

That's ridiculous. That said, it should be repairable. I'd contact Topping directly and see what service/repair options they have in place. Perhaps they may be open to replacing the unit or at least the main board.