\documentclass{scrbook}
\usepackage{scrlfile}
\PreventPackageFromLoading{mathpazo}
\usepackage[pdfspacing,eulerchapternumbers]{classicthesis}
% Latin Modern with oldstyle digits
\usepackage[%
rm={oldstyle,proportional},%
sf={oldstyle,proportional},%
tt={oldstyle=false,proportional=false,monowidth}%
]{cfr-lm}
% \mathbb
\usepackage{amssymb}
\begin{document}
\frontmatter
\tableofcontents
\mainmatter
\def\myaddress{http://it.wikipedia.org/wiki/Pagina_principale}
%\chapter[test]{\href{\noexpand\myaddress}{\spacedallcaps{test}}}
\chapter[test]{\href{\noexpand\myaddress}{test}}
This is a test for the font used. Here is $\mathbb{Z}$ and here
are the digits 1234567890 in text mode and in math mode $1234567890$.
\sffamily
Here are the digits 1234567890 in text mode (sans serif)
\ttfamily
Here are the digits 1234567890 in text mode (typewriter)
\end{document}

Here's the list of used fonts from the log file
</usr/local/texlive/2012/texmf-dist/fonts/type1/public/amsfonts/euler/eurb10.pfb>
</usr/local/texlive/2012/texmf-dist/fonts/type1/public/lm/lmcsc10.pfb>
</usr/local/texlive/2012/texmf-dist/fonts/type1/public/lm/lmr10.pfb>
</usr/local/texlive/2012/texmf-dist/fonts/type1/public/lm/lmss10.pfb>
</usr/local/texlive/2012/texmf-dist/fonts/type1/public/lm/lmtt10.pfb>
</usr/local/texlive/2012/texmf-dist/fonts/type1/public/amsfonts/symbols/msbm10.pfb>
and from pdffonts
name type emb sub uni object ID
------------------------------------ ----------------- --- --- --- ---------
KNQMFR+LMRoman10-Regular Type 1 yes yes no 14 0
GNBFRC+LMRomanCaps10-Regular Type 1 yes yes no 15 0
GNBFRC+LMRomanCaps10-Regular Type 1 yes yes no 16 0
KNQMFR+LMRoman10-Regular Type 1 yes yes no 17 0
PWNBSJ+EURB10 Type 1 yes yes no 28 0
AICAWW+MSBM10 Type 1 yes yes no 29 0
KNQMFR+LMRoman10-Regular Type 1 yes yes no 30 0
CTWEBZ+LMSans10-Regular Type 1 yes yes no 31 0
CTWEBZ+LMSans10-Regular Type 1 yes yes no 32 0
AUGYQG+LMMono10-Regular Type 1 yes yes no 33 0
If you don't want chapter numbers in the Euler font, remove the eulerchapternumbers option and issue
\renewcommand{\chapterNumber}{\normalfont\fontsize{70}{70}\selectfont}
after loading classicthesis; this will use Latin Modern also for the chapter numbers (modify to suit).
classicthesis, and maybe before loading your document class)\RequirePackage{scrlfile}\PreventPackageFromLoading{mathpazo}. See tex.stackexchange.com/questions/76297/… – lockstep Oct 13 '12 at 11:21classicthesisis quite rigid: take or leave. Trying to customize it is a lost battle. – egreg Oct 13 '12 at 12:35hfoldstyandlmodernare contradictory to each other. – egreg Oct 13 '12 at 14:17