Some info
Might be good for warped LPs that never made it to CD, I suppose, but probably not much else.
While constructing turntables (the first one in 1980), I was learning all the time about
mechanical and acoustical properties of materials, how to use and combine these
and find solutions. This enabled me in the beginning of the nineteen nineties to
optimize several CD players, mechanically and acoustically.
The mechanical and acoustical aspects are far more important than exchanging
capacitors, resistors, opamps, wires and connectors. I also found out that the
physical properties of the cabinet, especially the way the metal from which the
cabinet has been extruded and the cover has been molded, do contribute to the
quality and similarity of the individual channels. Already taking out the plastic rod
which is attached to the power knob at the front of the cabinet, resulted in a more
precise, less make-believe high frequency reproduction.
Applying damping material in certain places in order to control vibrations that interfere
with the proper reading of the samples, helped me to acquire a lot of knowledge.
First the side panels, the metal top of the cabinet and the mechanics of the tray and
the clamp that holds the CD down were distinctively treated. The next step is to
determine the exact spots were vibrations occur.
While damping a Denon CD player with small pieces of bituminous sheet, I followed
a specific pattern when all of a sudden the stage opened up, was getting larger and
deeper, the harmonics were improved and transient reproduction (the weakest
feature of the CD format) sounded more exact and natural.
The CD player was cheap compared to the high end machines of Mark Levinson and
Krell for instance. But when my optimized player was compared to these expensive
giants in the auditorium of a high end shop, the simple player was in the same league
in every aspect, except for the ultra low frequencies. There the cheap player lacked
strength because of its small power supply. It goes without saying that the player was
a multi bit player with Burr Brown converters.