[dvipdfmx] [tex-k] dvipdfm[x] problem with dashed horizontal lines

[Bob Tennent]

I'm trying to force dvipdfmx to use bitmapped musixtex fonts
(to avoid "Intolerable difference in glyph width" issues).
I've disabled musix.map and the musixtex fonts do not appear
in pdftex.map. Then dvipdfmx -v output includes

  <musixspx at 19.93pt(TFM:musixspx)
  pdf_font>> Simple font "musixspx" enc_id=<builtin,-1> font_id=<musixspx,1>.

yet the type1 versions are still appearing in the pdf.
How do I force dvipdfmx to ignore the type1 fonts and use
glyph widths from the tfm files (and presumably embed type3
bitmapped fonts)?

Bob T.