question about +4/-10 connection from pre to soundcard

[Hep D MC]

my focusrite trakmaster has 2 outputs that can connect to my 1212m. i read in the manual the +4 is for balanced and -10 is for unbalanced. i got a balanced mogami cable so i stuck it in the +4 and everything was cool. then one day i was messin with my patchmix and noticed it has the option of setting it to +4 or -10 and mine was set at -10. so i changed it to +4. after i did this tho i started picking up a lot of static/hissing sounds and i'd have to turn my gain up all the way and it still wouldnt b that loud. y is it that while the output from my pre is +4, it works better with my soundcard set at -10 as opposed to +4?

 

[drstawl]

The -10/+4 selection selects the expected level of the input.

If your input is expecting -10 and gets +4 it will see an obnoxiously loud signal and if it is expecting +4 and gets -10 the signal seen will be really weak.

The balanced/unbalanced deal is a wiring issue- whether or not an extra conductor is used to send a signal used for noise cancelling.

 

[Hep D MC]

thanx for replying but that doesnt really answer my question. i know logically, if the soundcard is expecting a +4 or -10 input then the pre should b set at the same level. but my question is, why does my pre work better when the output is +4 and i have my soundcard input at -10. i originally just plugged it into the +4 on my pre and called it a day. everything worked fine. later i realized my soundcard was set at -10 so i switched it to +4 and thats when i started having hiss/static problem and volume issues.