Direct Drive vs. Idler Drive vs. Belt drive

I’d like to know your thoughts on the strengths and weaknesses of each drive system.

Direct drive is direct. With an accurate enough clocking system, fast enough correction system, and a motor with a fast enough torque response, direct drive can maintain much higher speed accuracy than any of the others. The problem is all in what constitutes "enough". A good example if you want to get some idea of that is to read up on the Onkk Cue.

The weakness of direct drive is the challenge of dealing with vibration issues and motor smoothness (cogging) all of which are solvable, the question being at what cost. This is the one everyone leaves out, when in fact its the one that matters most. Its almost a complete waste of time to talk about the strengths and weaknesses while leaving cost out. Why do you think so many tables use acrylic and aluminum, and so many speakers use MDF? It ain’t because of their strengths and weaknesses. Its because they are cheap!

All the others, idler wheel, belt drive, are all trying to do the same thing. A belt is great for isolating motor vibrations from the platter. But it does that by stretching, which introduces speed variation, which is bad. Also the main reason for using belt drive is it lets you get away with a noisier motor that vibrates more. Well then the motor needs some kind of suspension to keep it from vibrating the plinth. And round and round you go playing with elastomers trying to get the right mix of vibration control with speed stability. All because its cheaper this way than building a proper motor.

Idler wheel is merely a variation on a belt. A variation that adds a bearing. Its crap, which is why it was so common early on and so rare nowadays.

The one you left out is rim drive, which is of course the best most cost effective solution, as why else would I have chosen it? https://systems.audiogon.com/systems/8367

Okay technically Chris Brady chose it. But technically technically it was a collaborative project of advanced audiophiles a sort of co-op called Teres Audio. So there.

In truth no one can say any one of these is the best, because this is a case of implementation being more important than technology. That’s why there are plenty of examples of great tables that use all these designs. That’s why once again the tech just ain’t all that and what counts is not can you figure out which tech is best but can you listen and hear which one sounds the best.

It appears Mike and I were writing at the same time. Lol! 

His experience perfectly illustrates what I was saying. Its possible to have great results from all of these designs. Look at it this way. If you asked a hundred engineers at least 99 of them would tell you the worst place you could possibly put an engine is way out back behind the rear axle. 99 out of a hundred will tell you that, and the one that doesn't flunked out of class. Yet the rear engine Porsche 911 has been voted worlds best driver's car by more magazines over more years than any other car by far. 

Sad to say Mike has no rim drive example. Oh well. Always room for one more, eh?

Mike, It is interesting to hear from you on this subject.  About 7-10 years ago, you had 3 turntables set up.  One was a tweaked Garrard 301, another was a Rockport Sirius, and the third was a Technics, as I recall, eventually replaced by a Dobbins Technics and then by Dobbins' The Beat.  Have I got that about right?  You were my guru on this subject. Based on your posts and those of some others, I got into experimenting with different drive systems myself.  Having never owned anything but belt-drives, I felt that I knew what they do, up to the price point that limits my selection.  So I acquired a Lenco and highly modified it, and eventually an SP10 Mk3 in slate+wood plinth, a Kenwood L07D, bone stock, a Denon DP80 in slate, and a Victor TT101 in a massy wood and aluminum damped plinth.  Again, I had to play in the cost area that is compatible with my level of affluence.  It has been a very educational experience.  I now run two turntables feeding one system that drives Beveridge 2SW speakers and three turntables feeding my main system that drives a pair of electrically modified Sound Lab 845PXs. It's wretched excess but fun to listen to the same LP interpreted several slightly different ways by the different turntable/tonearm/cartridge combinations.  I must say the highly tweaked Lenco (with input from Win Tinnon) holds its own quite nicely vs the 4 direct drives, and I firmly believe these turntables outperform belt-drives under $10,000 that I have heard.  However, a neighbor had a Dohmann Helix turntable with the built-in Minus K suspension.  That is a way more than $25,000 belt-drive that made me feel a bit of lust.  Or I should call it curiosity to try it in my own systems.  But that isn't going to happen because of cost.  Anyway, it's interesting that you decided to go back to having multiple turntables, after having been happy with the NVS for so long.  Carry on.

Sad to say Mike has no rim drive example. Oh well. Always room for one more, eh?

........and the Dodo bird is extinct for a reason. :-)

just kidding. Chris Brady’s turntables were enjoyable to listen to. and he was a good guy too.

seriously though, the rim drive and idler are the same concept turned inside out. again.....execution of those two similar 'high' leverage drive approaches is much more significant than the dogma of outside or inside.

@lewm

Mike, It is interesting to hear from you on this subject. About 7-10 years ago, you had 3 turntables set up. One was a tweaked Garrard 301, another was a Rockport Sirius, and the third was a Technics, as I recall, eventually replaced by a Dobbins Technics and then by Dobbins’ The Beat. Have I got that about right? You were my guru on this subject.

thanks Lew. and right you are. but back then my collection of turntables (other than the Rockport and NVS) was at more modest price points. i enjoyed my NVS these last 9 years, but decided to invest in a top level belt and top level idler as i found that the music was not ideally served by one drive approach. and it’s been great fun and musically satisfying getting back to having choices when playing vinyl.

the belt drive and idler i have now are as low noise and speed steady as my direct drive; and both are even heavier. all three have high mass platters and plinths.