Nice explanations on why different implementations and approaches to record playing produce differing sounds. Example turntables are the venerable Thorens TD 124 (idler) and the equally venerable Technics SP 10 Mark II (direct drive with motor controller).
http://www.lencoheaven.net/forum/index.php?topic=5529.0
This post is enlightening, and the analogy beautiful:
Quote:
I have not set up the Lenco yet, but I have replinthed, rebuilt the motor and replaced the thrust plate, motor grommets and ball bearing on the td-124 and it has lovely sound. All that David says about lingering decay of instruments and musicality that is describable if not explicable is there. I will, however, take a stab at it. In looking at sites that have info on rebuilding the sp-10 power supply, they discuss the early current draw when the unit is switched on and spun up to speed. Once the unit is at speed the ps cuts down the current to a few milliamps, which is all that is necessary to keep the unit spinning at speed. When confronted with a complex passage of music, the microscopic slowing is detected and compensated for by the feedback circuit in the motor. When the demand is gone, the unit reduces its higher current draw. The idlers we love work more like a washing machine. They go on and spin off of wall current and are speed regulated by the frequency of our voltage and the friction in the unit. Rather than having adjustable power supplies, these units are wasteful and are adjusted in speed with the use of brakes which apply more friction against the motor to slow it down. With the added inertial of a heavy platter, I think the idler rolls like a freight train and things that get in the way are blown through as if they were not there because of their negligible impact against the force of the system. The SP-10 with its adjusting current load is like a truck that changes gear as it meets hills and sometimes slows on the bumps before picking up speed and eases off the gas on the flats. Although it is more efficient, it misses some of the attack and when it passes a complex passage it eases off causing a loss of decay.
Sorry for the long diatribe, but I think these decks can be improved by adding rather than reducing intertia and friction. The engineers from Technics used to demonstrate the power of these tables by inviting users to place a record brush on a moving record and press down with force. Rather than stopping, the deck would compensate for the added load and spin on at constant speed. These turntables are designed for a greater load than they usually carry and may be poorly used as currently implemented. Perhaps a more viscous lubricant in the bearing, a heavy copper platter instead of a mat, and record weight could be accommodated by this design. An overhanging record brush, or two, may give the table the need to put out a little more power on all passages and may bring forward the attack and decay that some users find lacking. I wonder...
Unquote:
Emphases mine.
http://www.lencoheaven.net/forum/index.php?topic=5529.0
This post is enlightening, and the analogy beautiful:
Quote:
I have not set up the Lenco yet, but I have replinthed, rebuilt the motor and replaced the thrust plate, motor grommets and ball bearing on the td-124 and it has lovely sound. All that David says about lingering decay of instruments and musicality that is describable if not explicable is there. I will, however, take a stab at it. In looking at sites that have info on rebuilding the sp-10 power supply, they discuss the early current draw when the unit is switched on and spun up to speed. Once the unit is at speed the ps cuts down the current to a few milliamps, which is all that is necessary to keep the unit spinning at speed. When confronted with a complex passage of music, the microscopic slowing is detected and compensated for by the feedback circuit in the motor. When the demand is gone, the unit reduces its higher current draw. The idlers we love work more like a washing machine. They go on and spin off of wall current and are speed regulated by the frequency of our voltage and the friction in the unit. Rather than having adjustable power supplies, these units are wasteful and are adjusted in speed with the use of brakes which apply more friction against the motor to slow it down. With the added inertial of a heavy platter, I think the idler rolls like a freight train and things that get in the way are blown through as if they were not there because of their negligible impact against the force of the system. The SP-10 with its adjusting current load is like a truck that changes gear as it meets hills and sometimes slows on the bumps before picking up speed and eases off the gas on the flats. Although it is more efficient, it misses some of the attack and when it passes a complex passage it eases off causing a loss of decay.
Sorry for the long diatribe, but I think these decks can be improved by adding rather than reducing intertia and friction. The engineers from Technics used to demonstrate the power of these tables by inviting users to place a record brush on a moving record and press down with force. Rather than stopping, the deck would compensate for the added load and spin on at constant speed. These turntables are designed for a greater load than they usually carry and may be poorly used as currently implemented. Perhaps a more viscous lubricant in the bearing, a heavy copper platter instead of a mat, and record weight could be accommodated by this design. An overhanging record brush, or two, may give the table the need to put out a little more power on all passages and may bring forward the attack and decay that some users find lacking. I wonder...
Unquote:
Emphases mine.
