Your thoughts on linear tracking tt's

[KentT]

I prefer pivoted 12" transcription arms in daily service for practical reasons. SME being my favorite make but I also love Grace and Audio-Technica ATP lines and find the Jelcos to be excellent among others.

[dlaloum]

At 12" many of the tracking error issues get reduced substantially - on the other hand, offset angle issues and the associated IMD are only marginally reduced.

The other major tradeoff of a 12" arm is mass - simply put it is longer and therefore has substantially increased effective mass - the cartridge is further from pivot point, and the cartridge body's impact on mass is therefore magnified in inertial terms as well...

So a preference for 12" pivoted arms, requires a concomitant preference for low compliance cartridge designs.

There is always a tradeoff !!!

[KentT]

That is also why I have a second low mass tonearm mounted to use my higher compliance cartridges when I want to hear one.

[flavio81]

Well, for one, the paper "digital simulation of tracking distortion" available here at VE shows (IMO convincingly) that the tracking error of the typical 9" tonearm is of no concern at all.

On the other hand i think the REAL advantage of a linear tracking tonearm is that, since offset angle and overhang is zero, the modulation of the stylus signal by the (program modulated) skating force is completely banished.

And i think that THIS is what could give them an audible advantage.

[hi_torq]

It would seem that many linear tracking systems are designed for compactness above all else, which by implication means a shorter distance from stylus tip to vertival pivot axis. This leads me to think that on anything but a perfectly flat disc of optimal thickness, the VTA will be compromised far more than with a conventional-length arm.

[dlaloum]

You are quite right - and the theory is correct...

My own Revox is an extreme example of this as the arm is all of 2" long.

My own experience with lightly warped discs is that it tracks them like a trooper.

More seriously warped discs are a problem indeed... But they are just as much of a problem on my 10" JVC pivoted arm table, although I will admit that the JVC appears to handle them better when I enable damping - the servo damping makes it more capable with warps...

Another case of swings and roundabouts.

The type of records I have audible issues with on the Revox, will cause trouble on almost all tables... so I think this is more of a theoretical than a real issue.

The problem also appears to be limited to the outer 3cm of a records radius, once past that "danger zone" I have not noted a difference between 10" pivoted and 2" Linear...

[hope751]

Hello, Im David. Im a fan of Linear tracking. I have two Onkyo PL-25F players. I play my records on nothing but this player. I have had no problems except the belt that moves the arm. A very easy fix.Any way, Thats my 2 cents...

[ABEC-9]

Many of my vintage RCA shaded dog LPs have slightly off-center center holes... I wouldn't try playing these treasures on any linear tracking 'table, servo or not. But, the worst part, is that some of these LPs have that wobbling eccentric lead-out groove at the end of the LP... These were probably there to "wriggle" the tonearms of early automatic 'tables to trigger them to cycle. I've never heard of a linear tracking 'table playing something like that -- but it would certainly be fun to see!

[Aerobat]

Many of my vintage RCA shaded dog LPs have slightly off-center center holes... I wouldn't try playing these treasures on any linear tracking 'table, servo or not. But, the worst part, is that some of these LPs have that wobbling eccentric lead-out groove at the end of the LP... These were probably there to "wriggle" the tonearms of early automatic 'tables to trigger them to cycle. I've never heard of a linear tracking 'table playing something like that -- but it would certainly be fun to see!

LTs have no issues with off-center records. The problem with a servo LT is when it goes into high-speed mode to keep up with the groove, the motor noise is audible.

With the turntable in my avatar, there is no noise at all since the carriage is pushed back and forth via magnetic repulsion.

[Steerpike_jhb]

LTs have no issues with off-center records. The problem with a servo LT is when it goes into high-speed mode to keep up with the groove, the motor noise is audible.

On things like the Technics SL10, the motor can only drive the arm inward - it never reverses during play, so never corrects a 'negative' tracking error.
The Revoxes have tracking systems that follow the groove in both directions.

Most 'electric' linear trackers should pick up the arm and switch off before the lead out groove reaches the 'eccentric' part.

[PeterW.]

LTs have no issues with off-center records. The problem with a servo LT is when it goes into high-speed mode to keep up with the groove, the motor noise is audible.

On things like the Technics SL10, the motor can only drive the arm inward - it never reverses during play, so never corrects a 'negative' tracking error.
The Revoxes have tracking systems that follow the groove in both directions.

Most 'electric' linear trackers should pick up the arm and switch off before the lead out groove reaches the 'eccentric' part.

Rabco's ST-series as made by HK also track in both directions. Those are not servo-motor arms but friction-tracking based on an angled tire rolling on a precision shaft - hell on wheels to replace when the tire rots but elegantly simple otherwise.

[Aerobat]

Both the PL-L1000 and LT-30 track backwards as needed.

[fscl]

LTs have no issues with off-center records. The problem with a servo LT is when it goes into high-speed mode to keep up with the groove, the motor noise is audible.

On things like the Technics SL10, the motor can only drive the arm inward - it never reverses during play, so never corrects a 'negative' tracking error.
The Revoxes have tracking systems that follow the groove in both directions.

Most 'electric' linear trackers should pick up the arm and switch off before the lead out groove reaches the 'eccentric' part.

@Abat, possibly, however, I'm wondering if this is due to "effects of aging"....... of rubber that is..... Rubber is "magic" in our realm and serves to dampen and minimize vibrations. As our tts are now 30+ years on, all elastomers have dried out and the remaining rubber is not acting as it should whereby increasing tonearm vibration and transmission noises..... My rubber restorer has plumped up old rubber when left soaking / bathing. I anticipate that when these pieces are reinstalled that they perform as intended and minimize rotational / transmission noises......

@ SPJHB, IIANM, the Sony PS-X600 and PS-X800 can track my reverse groove Black Keys Record Store Day LP as in this:

http://www.youtube.com/watch?v=J1pdy33kmSM

I believe I have read some of KK5's Mitsubishies are reverse groove capable but not entirely sure. Keiko5 will have to chime in here.

Anyway, my off center Stevie Wonder Talking Book is well within the swing capability of all my Technics LTs. The short tonearm looks like a dogtail wagging and is quite hilarious since it sounds so seasick......

Fred

[Aerobat]

@Abat, possibly, however, I'm wondering if this is due to "effects of aging"....... of rubber that is..... Rubber is "magic" in our realm and serves to dampen and minimize vibrations. As our tts are now 30+ years on, all elastomers have dried out and the remaining rubber is not acting as it should whereby increasing tonearm vibration and transmission noises..... My rubber restorer has plumped up old rubber when left soaking / bathing. I anticipate that when these pieces are reinstalled that they perform as intended and minimize rotational / transmission noises......

Fred

Quite possibly -- what kind of restorer do you use? I have a product called Re-Grip that's meant for rubber rollers, but I haven't had much success with it.