Thank you for answer ramses and mc.
I'm sorry I do not know well about the audio processor and english.
I was bothered with bass boosting(+20db).
The bass trap failed.
The only remaining method was eq.
But I heard many negative opinions about eq from hifi.
Then I found this.
http://www.audioforum.co.kr/bbs/board.p … mp;page=29
It was written if Linear Phase eq works before the dac, there is no problem.
So I found adi-2 pro and bought it.
But manual was not translated.
So I tried to translate the manual into Google Translator.
But it failed.
And Of course I saw the dsp/dac in the picture.
But I could not be sure of this picture.
So I needed an expert answer.
And I am using this now.
shieldtv -usb-b- adi-2 -spdif(optical)- 8300cd(preamp) -xlr- 8300mb(poweramp)
There is a small problem.
A window about the connection was posted every 3 to 5 minutes.
So I set it manually and decided to remove 8300cd(preamp).
(Of course I saw the picture of the manual(preamp: analog-analog).)
And I asked a question in my country.
q. 'If the input is usb, does adi-2 work preamp?'
So I remove 8300cd(preamp).
But adi-2 does not work in preamp mode.
It only works with usb mode or dac mode.
So I was confused and asked a question here.