A Meltrope question

[Hogan]

I'm wondering if there is something I can do with this Meltrope III soundbox. It doesn't really sound much better than the exhibition on an open horn HMV machine I use. To me it looks like everything is in order, no damage to the diaphragm, the ball bearings are in place and the rubber is supple enough. Am I missing something? I expected a notable difference to a 1913 exhibition...

Greatful for thoughts!

H

Edited August 31 by Hogan
One picture too many

[Viva-Toenail]

Which rubber is "supple enough," around the diaphragm or the isolator?  Ideally both should be, but the latter is critical for Meltropes (see below momentarily...).  The rubber should compress and spring back to form (i.e., you want "bounce" not "squish").

 

Are you playing electric process recordings when comparing?  Try 1930s recordings (or later) if you haven't already.

 

Have you "tuned" the isolator while fitted to the tonearm?  This can be done by adjusting the compression (via the knurled nut) and adjusting the position on the arm. 

 

From the installation instructions: 

 

Quote

The tone of the soundbox can be varied by adjusting the tightness of the knurled nut, thus controlling the flexibility of soundbox on tone arm; also by sliding soundbox on tone arm in a longitudinal direction in different positions.