position of (treble) clef in musixtex when I use smallvalue or tinyvalue

The treble clef symbol moves to the right when I use smallvalue. When I use tinyvalue it moves to the right straight against the flat (or sharp) of the generalsignature. Where could I move the clef to the left, the very beginning of the line for all music? I tried things like deftreble{kern-2pttreble}, but it helps nothing.
The distance from the left side beginning of the line is totally independent from elemskip or noteskip, it is the same in now more than 1.000 scores so the "mistake" has to be found in the deeper TeX definitions, and I am not really familiar with changing them.

For aesthetic reasons I would be pleased if somebody could tell me where the position of the clef is defined.

I set this in plain:

input musixtex%1
input musixcpt%2
input musixlit% 3
input musixext%4
input musixlyr%5
input musixec%6
input pmx%7
fontA=phvb8t at 9pt%
hoffset=0mm% 
hsize=80mm% 
nopagenumbers% 
instrumentnumber{1}% 
setstaffs1{1}% 
nobarnumbers% 
generalsignature{-1}% 
generalmeter{allabreve}% 
enableauxlyrics% 
afterruleskip=0.4afterruleskip% 
setsize1tinyvalue% or smallvalue or no setsize1 
Asetlyrics{soprano}{Aan de oe-ver van het meerrlap{,} luist'-ren ve-len naar de Heerrlap{.}}% 
forcelyrhyphenstrue% 
parindent 0pt% 
nostartrule% 
startpiece% 
accshift=0.5pt% 
assignlyrics1{soprano}% 
notesqqskqu fqu gbskhskenbar% 
notesqu hql jql kql jhbskenbar% 
notesqqskhu hen% zalaligne% 
notesql jqu hhbskenbar% 
notesql jqu hqu gqu hhbskenbar% 
noteshu fcaesuraen% 
Endpiece% end{music}%