Why According to some Turntable extremists Pitch Control and Direct Drive is Sacrilege?

Look who let the cat out of the bag mr wonderful @rauliruegas 

@stringbeam just wait and see.

@lewm ive spoken to many in real life who view pitch control and DD as not audiophile. Those would be Linn owners and those who own multi thousand dollar turntables. 

I swapped out my modified Project Debut III for a vintage automatic Technics DD turntable. I realized that my audiophile zeal for manual TT's has subsided as I got old and lazy and didn't want to have to leap out of my chair at the end of an album side. The Project did sound a bit better on bass extension, but the Technics is dead silent and built like a tank. I generally stream music and listen to my albums less and less.

I don't think I've heard any reasonable person make blanket statements about either pitch control or direct drive tables.  However, I have heard about specific tables and specific implementation of both; as is always the case, people can make any issue quite complicated.

There are a lot of people that did not like the sound of certain specific, iconic direct drive tables, like the Technics 1200, and even the SP10.  They claim that a lot of those tables have a hard or brittle sound.  I've heard that quality with some direct drive tables, but, I have no way to attribute that specifically to the drive, given that there are so many other design factors involved in any table, nor did I hear this with ALL the direct drive setups I heard.  I've heard speculation that this quality is the product of the servo system constantly making small speed corrections, but, again, I have no way to determine if that is the case.

I don't think anyone objects to having pitch control, the issue is how such is implemented and whether the implementation hurts the sound.  For example, with AC motors (synchronous), if you have a two-phase motor where the phase is split by a capacitor, changing the frequency of the AC to adjust speed would not be theoretically ideal because the phase splitting capacitor was chosen specifically for one frequency (60hz or 50 hz).  Whether the slightly asymmetrical sinewave that results from just changing frequency really matters, is the subject of debate.  Some manufacturers, like Basis, provide a controller with two channels of AC supplied to the separate phases of the motor to prevent any such problems, others do not go this approach because of the obviously higher expense and trouble (the motor has to be re-wired to work this way).  

I don't have any particular issue with people adjusting speed to better match the ideal.  But, I do think there are a lot of people who make absolute speed accuracy a fetish, even if the minor speed inaccuracy is well within the range of inaudibility to someone with the gift of absolute pitch.  If is far more important that the table delivers stable speed that does not have small, rapid, speed variations (flutter) or the slightly slower variation (wow); if the average speed is perfect, but there is a lot of wow and flutter, the table will sound like crap.

I think the OP maybe needs to define and understand the question he just asked.  Are we talking about speed adjustment with a external knob.  Electronic automatic adjustment somewhat continuous.  Are we looking for the right 33.333333333 or that 33.33333333 not to vary or be stable.

The debate is normally over stability and mass vs electronic correction.  This gets into a endless debate which can be resolved  by listening.  OK that would require that someone could hear pitch with some sort of accuracy.

Seeing a stereo/ mono switch has nothing to do with pitch or speed, it might give us a insight into the OP intent or knowledge on the subject.

Enjoy the ride
Tom

Michael Fremer has written, and I agree:

"Regulating a direct-drive motor's speed with a phase-locked loop produces tight speed control and measurably low levels of wow and flutter, but the motor's constant, ultra-high-speed hunting and pecking as it over- and undercompensates in the attempt to produce a consistent speed can create a jitter effect in the mid-treble to which the human ear is particularly sensitive, adding a hard, brittle texture to music. That describes the sound of Technics' now-discontinued SL1200 series of direct-drive turntables, and explains why, despite their high build quality and relatively low price, few are used in serious audio systems, though some listeners claim that these 'tables can be modified to improve their sonic performance."

That doesn't mean that DD cannot be built that doesn't have this issue.  It has been done for generations, but they have usually been quite expensive.  As the prices of high performing belt drive TTs has gone up and that of high performing DD TTs has come down (as for ex. VPI) the market is changing.