Turntable Speed Precision

[catastrofe]

It seems that measuring devices are both a blessing and a curse, as they typically lead to a serious attack of Audiophillia Nervosa. Case in point; the Feickert Platterspeed app available from the iTunes store. When I listen to my analog front end, it sounds excellent and I don't really notice any deficiencies. Of course, I don't have a second point of reference.

Below are the Platterspeed results after dialing in my speed as tightly as I can. The question at hand. . .is this acceptable precision? I think I can hear the test tone change in pitch when speed decreases around .2%, but I'm not positive. I don't notice a difference on the increase side.

I'd really like to determine whether my results are typical, or if my table has an issue. I'm also wondering if arm alignment can impact this measurement. . .I do see back-and-forth movement of the arm as an album plays, on pretty much every album.

 

[Phelonious Ponk]

Back in the day, when we used to learn to play guitar by playing along with records, record players were a nightmare. They were so far off, you'd have to re-tune your guitar to the record before you could make it work. Not so bad if you already knew what key the song was in, but.... Then along came the direct drive turntables with speed adjustments. A godsend. Is tuning accuracy better with digital? Sure. But even the very early Technics direct drive tables did the trick. Is your table direct drive? Better than a stock Technics from 1975? Then the odds are pretty good I could walk in with a guitar tuned to standard pitch and play along, all the way through your Beatles collection. And come on. This is What's Best, not What's OCD. That's plenty close enough. Turn off the software and listen to side 2 of Revolver.

Tim

 

[jazdoc]

This subject was recently flogged to death on Audiogon:

http://forum.audiogon.com/cgi-bin/fr.pl?eanlg&1320876538&read&keyw&timeline&&st0

 

[MylesBAstor]

This subject was recently flogged to death on Audiogon:

http://forum.audiogon.com/cgi-bin/fr.pl?eanlg&1320876538&read&keyw&timeline&&st0

Yeah flogged is a good word.

 

[catastrofe]

Yes, but we're a much more sophisticated group here, and can have a meaningful discussion without descending into the abyss. I think. . .

 

[jazdoc]

Yes, but we're a much more sophisticated group here, and can have a meaningful discussion without descending into the abyss. I think. . .

Wanna put a bottle of scotch on that and make it interesting?

 

[rockitman]

I use a fluke meter (frequency test). Using a 1000 hz test tone on a test record, I typically oscillate between 999 and 1000 hz. I can't seem to detect a pitch change audibly. Should 1 hz difference be audible at that level ?

 

[MylesBAstor]

Wanna put a bottle of scotch on that and make it interesting?

Man you're an optimist Mark!

 

[FrantzM]

Hi

I for one am interested in such a discussion. The most interesting thing of this forum is the presence of people with vast experience and willing to share and/or educateus on the things that would make our systems better.
I moved away from a die-hard analog to a digital-stance but am back to analog becasue of an LP collection that I got and acquired a Technics SP-10 MKII and with that thing I can brush a record and it will maintain its speed. It starts in a flash and the speed seems constant at least according to the Stroboscope.

I have heard several discussion on speed variations and in the case of the Technics Iam not sure stylus drag would change anything abut its speed: I can safely and repeatedly brush a record while it's playing on the SP-10 and while I am sure the force I apply is not constant the speed remained constant ...

When do speed variations become audible? .. How accurate are the top TTs out there? How accurate do they need to be?

 

[catastrofe]

Maybe some of our fellow analog fans can post their results using Platterspeed. All it takes is an iPhone/iPad, the app, and a 3150 test tone (available as track 10/side 1 on the Analog Productions test record).

 

[mep]

Nobody answered Cata's question. I can't see the damn graphs good enough to make out the meaning of them. Tim-I might just listen to side 2 of Revolver tonight. Cata-what table do you have?

 

[mep]

Hi

I for one am interested in such a discussion. The most interesting thing of this forum is the presence of people with vast experience and willing to share and/or educateus on the things that would make our systems better.
I moved away from a die-hard analog to a digital-stance but am back to analog becasue of an LP collection that I got and acquired a Technics SP-10 MKII and with that thing I can brush a record and it will maintain its speed. It starts in a flash and the speed seems constant at least according to the Stroboscope.

I have heard several discussion on speed variations and in the case of the Technics Iam not sure stylus drag would change anything abut its speed: I can safely and repeatedly brush a record while it's playing on the SP-10 and while I am sure the force I apply is not constant the speed remained constant ...

When do speed variations become audible? .. How accurate are the top TTs out there? How accurate do they need to be?

Frantz- I believe that Technics used to advertise that you could hang 50 arms off of the SP-10 MKII (if you had the room) and have all of them tracking a cartridge at 15 grams and it wouldn't change the speed. That table comes up to speed before you can get your finger off of the start/stop switch and the table stops before you can get your finger off the start/stop switch.

 

[Bruce B]

This got me to thinking.... why can't turntables be as stable as Studer tape machines? I can put on a MRL tape and it's dead nuts accurate at 16 and 20k !!

 

[catastrofe]

Nobody answered Cata's question. I can't see the damn graphs good enough to make out the meaning of them. Tim-I might just listen to side 2 of Revolver tonight. Cata-what table do you have?

TTWeights GEM rim drive. I don't have Revolver, but I am listening to Yellow Submarine.

 

[mep]

I have to admit that I have never heard of this table and therefore know nothing about it. It looks like a belt drive and it looks flashy. Does it have an outboard speed controller?

 

[Mosin]

I have to admit that I have never heard of this table and therefore know nothing about it. It looks like a belt drive and it looks flashy. Does it have an outboard speed controller?

It is a rim drive that is powered by a big Bodine motor. There is a thread all about it on Audiogon. I have never heard it, so I cannot voice an opinion.

One of these days I'll make a post about what I think makes a good turntable, if anyone is interested. Speed control is a major part of it, but that involves a lot more than just adding electronics to control the motor. I truly believe that the approach should be one that encompasses every aspect of the design. I don't believe I am alone in this philosophy either. That's why the Studer tape machines are what they are, in my opinion. And, yes Bruce, such accuracy is possible in a turntable.

 

[catastrofe]

I don't believe there's a thread about the GEM on Audiogon. There was a post about the TTWeights Momentus that was purchased used and the owner wasn't happy. Rather than contact the company, he began posting negative comments on AG. Mosin is correct, this is a rim drive table. It was reviewed last year on Dagogo. It does have an outboard controller.

 

[MylesBAstor]

This got me to thinking.... why can't turntables be as stable as Studer tape machines? I can put on a MRL tape and it's dead nuts accurate at 16 and 20k !!

Technics used the same motors for the turntables and tape decks.

One also seems to forget that LPs are mastered on direct drive machines with Al platters weighing 300 lbs. How speed stable is that?!?!

 

[Bruce B]

One also seems to forget that LPs are mastered on direct drive machines with Al platters weighing 300 lbs. How speed stable is that?!?!

How many people use a Neumann cutting lathe for their LP playback??

 

[jazdoc]

One of these days I'll make a post about what I think makes a good turntable, if anyone is interested.

Uh, yeah, I'm interested! Would be a tremendous thread topic.