S/N ratio Balanced input vs. Unbalanced input

@kijanki Thanks for pointing out. I hope so.

But, when i checked the previous model E270, the S/N ratio for balanced input is 91dB, unbalanced input (high level input) is 108dB.  

I am confused.

@kijanki I just check E270 vs E260 technical paper,

E270 noise voltage is 35microV at -30dB volume position

But in the above E280 technical paper, E270 noise voltage is 41 microV.

I am more confused now.

https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.accuphase.com/technical_information/e-270_technical_information.pdf&ved=2ahUKEwjtyazZz-j4AhV-wzgGHZfuC8QQFnoECA4QAQ&usg=AOvVaw1aVU67BSPqeah_5DXshwqG

@kijanki the reason I ask is I can hear noise (hiss) from tweeters when my balanced input (Denafrip Ares II) is connected while music is stopped playing. Volume changing not affected the hiss sound. 

Can you hear it from distance of 1m?

@kijanki Nope, only audible at near field,  close to tweeter.

If this is not abnormal, then I am relief.

Auronthas - can you compare the hiss, changing to single ended input?

@o_holter since my Ares II manual stated only XLR or RCA can be connected at one time, I have tried RCA before, and I can hear the same hiss.

@o_holter yes, the hiss is constant, with no variance on volume, the hiss is there with power standby on my DAC Ares II , only it’s gone when I unplug the power cord

No more hiss if DAC is disconnected

Are you sure other sources into the amp don’t give the hiss?

@o_holter Ya, I tried my old Sony CD player which connect to integrated amplifier via RCA, I did not notice any hiss near tweeter.  I will do fast "switching" from balanced input (Ares II DAC) and RCA input (Sony CD player) to test the hiss noise.

adding "Cable Clamp Clip RFI EMI EMC Noise Filters “ 

@westcoastaudiophile my audio equipment are connected to a good power conditioner of Novaris brand.  I would think EMI issue shall not be the case, wouldn't it ?

@atmasphere What you said make sense. I will leave it if this not a defect, just not perfect.  Thanks