Idler Drive

[Tea24]

What is it exactly that makes an idler drive so authoritative, especially when re-plinthed? I have heard it said that it is the weight of the platter, but other drive type TTs have heavy platters. My Notts Analogue junior spacedeck has a heavy platter and is a very good performer, but it lacks the slam of my Lenco, though I dare say more upmarket Notts Analogues might get there.

Others talk about the torque of the motor, but Notts Analogue has a tiny motor which won't even get the platter spinning without help! IMHO however all belt drives need an electronic speed controller.

I am fascinated as to WHY exactly the idlers should be so good.

[Dominic Harper]

Hi Julian. Belt drive turntables often use very high mass platters to make up for other shortcommings in the design. The heavy platter offer increased speed stability and reduce cogging effects from the motor plus other negative aspects of using a belt.
Idler drives have their own issues of course, many needing high mass plinths to extract best performance. Adding a platter of the kind of mass that your NA has to an idler would not be a good idea.
They rely on a platter of some mass of course, but over doing it would impact on an Idlers speed and attack.
Motors in the Garrard 401/301/ Thorens TD124 and the Lenco's are massive compared to the majority of belt drive turntables, and as such produce large amounts of torque. This produces a turntable with vice like grip on recordings.

[John]

You have to remember how much cartridge drag adds to speed stabilty thats why a lot of us perfer either direct drives or Idlier/rim drives. Each approach has it own issues to overcome; the major issue for Idlier based TTs is rumble, with direct drives it is ensuring the good speed stabilty and this is a reason why power supplies makes such a difference, with belt drives its about limting the effects of belt slipperage this is why very high end TT have such big platters. Of course there other factors to think about too. Each approach when done right can be very addictive.
The good news is we still learning how to get more out of vinyl