AL, just to correct you regarding the 'ping' on Ayon spinners when you press play or change inputs, that 'ping' sound comes from the 6H30 tube filament and is very normal. Ayon do not use any negative feedback or compensators to erase tube noise or hum or something like as most other manufacturers are doing.
Ayon are taking a pure approach. To use negative feedback in the circuit – the sound decreases a lot.
Ayon are taking a pure approach. To use negative feedback in the circuit – the sound decreases a lot.