From hero to zero! Sony did many things with the classic walkman, not all good.    This is the story of the wm-DD1.  It was an attempt by Sony to reinvent  the classic walkman 5!  Sony used cheap plastic parts on the inside, but kept the Full Metal Jacket on the outside! The result was a bulky, cheaper player that was nothing like the original. 

What a beautiful selection of Walkmans; it’s a shame the quality suffered on the later ones.

Sorry for any confusion. I do have the players mixed together for comparison.  The cheap version has all round buttons. It lacks the STEREO stamped in  by the headphone jacks. Plus the fact that only one headphone jack exists. These are the obvious cost cutting measures  Sony fans will notice.

I already felt that the DDI and other similars were lower in quality, but never heard one. Are any of yours in working condition? Is there a big difference in sound? Do they suffer from the same cracked center gear?

not only do they not function right, they rumble so bad that it can only be described as a tank rolling  by.  All of them!

Did Sony ever change the material used for the centre gear wheel to make it more robust?

To be fair to Sony these were two completely different produçt lines. In fact, the larger one was only availible in çertain parts of Europe.  The WM-2/DD line retained it's quality throughout it's 12 year legacy from the WM2 in 81 to the DD33 in 94. 

The larger and much inferior DD1 unit really was nasty by comparrisson but to be fair it was a £65 walkman compared to the £150 DD30 of the same period'

Agent Orange is right. The WM-DDI wasn't intended as a successor to the WM-DD and was really meant as a cheaper alternative to the excellent -DD player. It was perhaps Sony's intention to develop a cheaper line of disc-drive players that would replace the traditional belt-drive players. We will never know that for certain of course but if it really happened, we might have seen better players than WM-DC2. 

very good response! Thank you everyone!  My intent was no to copy walkman central, but to vent my frustration with some of these players of mine, and to have a chance to display my Sony DD line.  My favorite is the DD-30!    I am also not a spokes person for Sony. I do enjoy re examining the quality and design of the many units of the period.  It also takes me back to a different time with many fond memories.  I was just starting high school when many of these  Sony models were first introduced!