\usepackage[T1]{fontenc}
\usepackage{lmodern}
\DeclareFontFamily{T1}{lmr}{}
\DeclareFontShape{T1}{lmr}{m}{n}{<-> ec-lmr12}{}
\DeclareFontShape{T1}{lmr}{m}{it}{<-> ec-lmri12}{}
\DeclareFontShape{T1}{lmr}{m}{sl}{<-> ec-lmro12}{}
\DeclareFontShape{T1}{lmr}{bx}{n}{<-> ec-lmbx12}{}
別のファミリも同じようにできそうです。