Turntable speed accuracy

Dover, I think my response to you was too harsh. I apologize. Denon DP80 uses a 3-phase AC synchronous motor and also uses a quartz-referenced servo. Speed is monitored via a tapehead that "reads" the inner rim of the platter as it rotates. Knowing this, I was a bit confused when I read about The Beat turntable, which also uses a 3-phase AC synchronous motor that is claimed to self-correct by virtue of being so. (I think with The Beat there is a small amount of constant drag on the bearing, and the motor works against that.) Suffice to say that we need a motor expert here to straighten this out. I do think that the motor technology has not changed at all since the late 70s and that the designers of the tables you list used motors that they felt were best suited to the task. There are many high-dollar belt-drive turntables that use DC motors and no servo, as you know.

Lewm, no worries. I think there is a lack of real info as DD manufacturers and vendors placed more focus in their advertising on the fact that it is DD. I know the SP10mk3 and Lo7D well and agree with your descriptions of the difference in sonic signature. The Denon DP100 looks very interesting.

Travis has a DP100. But where is Travis (aka T_bone)?

Lewm: "Lets keep in mind that what you quote from the Brinkmann website is a commercial"

Yeah, I know. It's full of their own propaganda but I was too lazy to edit the pertinent parts so I just posted the entire section on drive system.... didn't mean to impose their bias on anyone. But it's still a good read for me and for the most part I agree with them about having a gentler servo system instead of a iron-fisted one and it resembles my own experience, granted there's always exception out there. I think this is a great thread as it allows people to focus on one of the most important and underrated aspect of a turntable: speed accuracy. It's been fun.

P.S. Yeah, where is Travis or T_bone? I miss him.

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I sent him a private email about 10 days ago but have had no response. He recently moved from Tokyo to Hong Kong, but he was communicating with me even during the packing and moving phase. He should be stabilized by now in HK.

It may be overly simplistic to think of a particular servo mechanism as "tight-fisted" vs "gentle". From speaking to Bill Thalmann, I gather that these circuits are quite complex, and the real differences in how the different ones operate may be accordingly complex as well. One is nevertheless free to choose a favorite based on listening.