1/8" ministereo input has NO line level ability. Only the dual 1/4" input has the higher +3.2 dB line level acceptance without clipping.
Refer to chart of input characteristics at: www.sonicstudios.com/mt2496rv.htm#inputs
I am referring to the 1/4" inputs only. I and several other people have posted on TS about the 1/4" line inputs being unable to take a domestic line level signal (with v1.4.5 firmware, 27dB boost off, L/M/H set to 'L' and recording levels set to minimum).
Edit:just done some "tests".
i) cd player line-out directly into MT's 1/4" inputs - red clip lights constantly lit
ii) same cd but via hifi amp line-out into MT's 1/4" inputs - red clip lights constantly lit
iii) same cd via hifi amp line-outs>-18db passive attenuator box set to full attenuation - unclipped signal peaking at the "-12dB" mark on the MT as per
http://www.sonicstudios.com/mt2496rv.htm#vuAt all times with v1.4.5 firmware, 27dB boost off, L/M/H set to 'L' and recording levels set to minimum. As a comparison, my D8's line-in will take these signals happily but cannot take a +4dB without attenuation.