Rccc you can believe whatever you like but you should do so in the face of the available evidence:
1. Belt creep exists (see Mosin's post for one argument, there are several others)
2. I can measure it.
3. Doug Deacon can hear it.
Ketchup, if the lathe slowed down for a transient the recorded signal would rise in frequency. The playback would need to slow down by an equivalent amount to replicate the "original" signal.
The folks at Pristine Classical in the UK have extensive digital files of works which they have taken off disc and have performed analyses of the changes of frequency within sustained notes. They do this so they can find artefacts of the recording process and correct for them. From what I have seen there is no great effect attributable to the lathe slowing down under cutter drag.
I can think of two reasons why this might be: firstly, don't forget that the cutter head was heated and used on a relatively soft acetate formulation - very much like a hot knife through butter.
Secondly, modulation drag exists because the hysteresis of the cartridge suspension removes energy from the system, the larger the modulations the larger the energy lost. The only source of "make up" energy is the motor (everything else is passive).
The cutter on the other hand is actively driven so the larger the modulations the larger the amount of energy being put into the system. If the energy lost through frictional heating equals the energy inserted into the system we'd be in net balance.
1. Belt creep exists (see Mosin's post for one argument, there are several others)
2. I can measure it.
3. Doug Deacon can hear it.
Ketchup, if the lathe slowed down for a transient the recorded signal would rise in frequency. The playback would need to slow down by an equivalent amount to replicate the "original" signal.
The folks at Pristine Classical in the UK have extensive digital files of works which they have taken off disc and have performed analyses of the changes of frequency within sustained notes. They do this so they can find artefacts of the recording process and correct for them. From what I have seen there is no great effect attributable to the lathe slowing down under cutter drag.
I can think of two reasons why this might be: firstly, don't forget that the cutter head was heated and used on a relatively soft acetate formulation - very much like a hot knife through butter.
Secondly, modulation drag exists because the hysteresis of the cartridge suspension removes energy from the system, the larger the modulations the larger the energy lost. The only source of "make up" energy is the motor (everything else is passive).
The cutter on the other hand is actively driven so the larger the modulations the larger the amount of energy being put into the system. If the energy lost through frictional heating equals the energy inserted into the system we'd be in net balance.