plugging a Cdplayer to Vintage sx-880 Pioneer

i tried both Aux and monitor tape 1 or 2 i dont understand why the monitor tapes inputs sounds better to me and the aux sounds louder but too much mids a highs a little bit exagerated i read many people prefer the monitor over the aux .

Make sure the "Loudness Switch" is in the off position.

People said output of cdp are 2V and input line are 150mv and so .

I believe the "tape in" inputs and "AUX" inputs are 2v

I could not find an owners manual for the SX-880.
Here is the service manual for the SX-880.
Note the #3 Block Diagram.
http://akdatabase.org/AKview/albums/userpics/10004/Pioneer%20SX880%20Service.pdf

Loudness is off
i  ve already had the same services file  from that data base well what i m trying to do now is adjust dc power offset to hjave the same level in each channel because now right channel is louder but the diagram is uncomplete picture and instructios refering some pointed numbers not showed at photo ????? Thanks

• according service manual 

  
  

• input/sensitivity

• phono 2.5mV/50kohms

• AUX  150mV/50kohms
  

• tape play  1 an 2 the same  150mV/50kohms
  

Thanks

• 
  

Let’s work through a real example to make things easier to follow (using data for my Pioneer SX-1250 receiver and Marantz CD-65SE CD player - typical of many vintage amp / modern CD player combinations) :

Input sensitivity of SX-1250 "Aux" (and "Tape") inputs : 150mV
Output voltage from CD-65SE at maximum signal level : 2000mV (2V)
So the CD player output signal is 20 * log(2000 / 150) = +22dB higher than that required for full output power from the SX-1250.

What this means is that the receiver’s full power of 160 watts will be produced with the volume control set to -22dB (referenced to maximum = 0dB). Fortunately, in common with much high-end equipment, the SX-1250 has a volume control marked in -dB, making it easy to see where this occurs.

Perhaps the most "surprising" thing to come out of this calculation is just how little the volume needs to be turned up to get full output : -22dB on the SX-1250 corresponds to somewhere between the 11 and 12 o’clock positions.

http://audiokarma.org/forums/index.php?threads/amplifier-sensitivity-decibels-and-you.58829/

More:
http://www.hi-fiworld.co.uk/amplifiers/75-amp-tests/150-sensitivity.html

http://www.decware.com/paper55.htm

https://www.vintage-radio.net/forum/showthread.php?t=101306

http://forums.stevehoffman.tv/threads/is-your-cd-player-changer-too-hot.350381/page-4