Topping A90 Headphone Amplifier Review

[Snoopy]

I just got a topping a90 and it works perfectly swell. my only issue is i hear a slight high pitched whine on the unit (without headphones just listening to it with my ear near the front panel). Should i be worried? Funnily enough my d10balanced also has a whine which i hope i can fix with a usb power isolator.

probably the power supply or some capacitor that you hear . I also hear that type of noise from laptops, routers , phone chargers etc when I get close to them.

 

[SmokedBurger]

probably the power supply or some capacitor that you hear . I also hear that type of noise from laptops, routers , phone chargers etc when I get close to them.

normal for these types of electronics right? though this is the first time ive ever heard it in an amp hahaha