The best Japanese SLT turntables. A comparison.

[Professor Bizzt]

Main bearing lubrication

Oh dear, disaster at the cricket, but, back on topic, I've serviced my SL-7 but am wondering whether I should apply some oil to the spindle/bearing.

Your thoughts, please.

The Technics SL-7 is off topic because it's a P-mount SLT design, but anyway here is my advice.

All turntable main bearings are very, very, tricky to properly lubricate so as to not make scraping noises. The fact that they rotate so slow does not allow a proper continuous, unbroken, and radially rigid lubricant film to form and build a positive condition known as hydrodynamic or fluid lubrication. Instead we are left with a lesser lubricating condition known as boundary lubrication.

Since the physics of proper boundary lubrication are fairly complex and demanding to implement properly, I recommend not altering or adding what you may think is the ultimate lubricant to a main bearing unless it is surely determined there is excessive scraping noise or that the level is significantly low as in the case of the very few turntables that allow adding oil via a removable spindle cap. Even then, the lubricant of choice and your procedures must maintain immaculately clean protocol.

Even if you determine that your bearing is making abnormal noise, you are in for a real roller coaster ride in getting it to quite down. This is a complicated subject.

Bottom line; don't lubricate a main bearing unless it is making noise beyond the norm.


Best wishes, Professor Bizzt

 

[Professor Bizzt]

Denon, Pioneer, & Sony FG tachs & the PL-L1000A tonearm IC

Pio1980
"The platter rim-reading FG tachs on the Sony and Denon TTs are probably the highest resolution PLL correction refs in common practice. Dunno how much diff this makes in correcting for stylus drag but iin theory should be better I suppose.

Is the L1000A LSI unobtanium off-the-shelf as far as you know?"


Hello Pio1980,

Yes, the platter rim FG designs of the Denons and Sonys are higher resolution, but they only integrate the signal over about 8 poles max (correct me if I'm wrong please) on their pickup heads. The Pioneers on the other hand integrate over the whole 360 degree surface of the FG.

What does this mean? It means that any slight inaccuracies in the encoding uniformity (and there can never be perfect uniformity) of the platter rim magnetization is compensated for in the fully 360 degree integrated design of the Pioneer FG.

The fact that the 1000A uses a large diameter FG of respectable and sufficient resolution AND peripheral integration I think makes it a respectable design. I would love someone who knows the engineering of tachometer drives to post on this thread.

As far as the central LSI chip responsible for the logic control in the PL-L1000A, I don't know what its availability is without spending time to check. I'm sure someone could get the part number from the Vinyl Engine's download-able service manual and post their results here.


Best wishes, Professor Bizzt

 

[Professor Bizzt]

Responsible use of lubricants & cleaners

Directed to readership in general, the prof knows what he is doing;
I have used Naphtha (lighter fluid) lightly 'dampened' towelettes to clean and degrease plastic and metal sliding components in similar items, followed by dry oiless/greaseless Teflon spray lubes. It is absolutely necessary to ensure that the spray's volatile vehicle will not soften/dissolve plastic components, lacquers, or anything else in whatever is being serviced/treated.
Never ever use alcohols, acetone, or any other solvent without establishing harmlessness beyond question, there is definite potential to cause permanent irreversable damage/destruction of the project in question.
Lastly, never ever slather anything like this in WD-40 unless prepping a vintage motorcycle engine for de-greasing.

The art of turntable restoration, repair, and modification is one that requires precision, conscientiousness, talent, and careful thought prior to implementing action. The topic of lubrication is very much one of those areas.

I cringe when I hear of someone taking a can of lubricant (WD-40 seems all the rage) and just carpet bombing their turntable with it. NO, NO, NO. Please don't do that.

Carefully chosen lubricant of the appropriate type must only be applied to specific areas and only in conservative quantities. Many times these areas are inaccessible without dismantling.


Best wishes, Professor Bizzt

 

[Professor Bizzt]

Yamaha PX-1

The best stock Japanese linear tracker would probably be the Yamaha PX-1.I have read reports of a fellow who owns one,as well as most of the desirable TOTL Direct Drives and he reckons that it is just outside of the very best Japanese direct drives.

Hello theophile,

Thank you for your input. I think we would all love to hear more about the PX-1 and PL-1 or any other rare super flagship SLT models from Japan. That would certainly make this thread more interesting.

If possible, perhaps you could encourage your PX-1 contact to post.


Best wishes, Professor Bizzt

 

[Professor Bizzt]

Sony PS-X800

The Sony LTs seem to escape attention and are supposed to be at least competitive with other sub-"statement level" examples. I would personally find a PS-X800 interesting.

Hello Pio1980,

I have now completed two Sony PS-X800 full calibrations and one was a complete restoration after being totally disassembled. This was necessary due to a very bad accident in a past shipping accident from a previous owner. One whole corner of the BMC plinth was missing and had to be rebuilt via a mold and fiberglass. Pictures are on the Vinyl Engine. I am also scheduled to perform a third PS-X800 calibration and another on a PS-X555ES.

Sony has several patents on the Biotracer tonearm concept. One of them is patent number 4138121. I encourage those interested to read up on this.

I spent a considerable amount of time getting to know the PS-X800 during its restoration. For some reason, I kept describing it as the Ferrari of SLT turntables. Indeed, one other poster on Audiogon said that it was more sophisticated than the missile guidance systems he had worked on while in the military.

As much of a pain these are to work on, and how you just cross your fingers hoping nothing will break in the long run once the owner takes delivery, I can't help getting a chill up my spine being around and listening to one of these. A very cool SLT table designed by dyed in the wool maniac Sony engineers.

Having said that, the one I restored went to the same guy that the the PL-L1000A went to. I modified the PL-L1000A with my PL-L1000A tonearm and plinth mod and identical Panasonic EPC-451C strain gauge cartridges were installed on both turntables. My customer is having a very difficult time determining which is better.


Best wishes, Professor Bizzt

 

[Pio1980]

Thnx much for comments re PS-X800. Perhaps the PS-X555ES might be a more sensible choice for simpler implementation. E-mail sent re PL-L1000/1000A.

 

[koseltri]

Great thread going here. As far as 1/2" mount DD LTs, I own the following:

PL-L1000 (and identical twin PL-8000)
PL-L1000A
PL-L800
PS-X800
PS-X555ES
LT-20
LT-30
PX-3
AP-L45 and 95
PX-101

I wasn't as impressed with the 1000A. If you say the motor is an improvement, I'll take your word for it. I consider it inferior due to the fact that the bearing is in the rotor and not in the stator, which removes any sort of reservoir for the motor's lubricant. I had heard it mentioned that the 'A' was fitted with a carbon fiber tonearm. Mine is definitely not, it is black painted metal. From a convenience standpoint, i much prefer the rotary shuttle to the pushbutton one. And the plastic bearing surfaces on the L800 are severly worn, they were in this condition when I got it. It is not being used due to the high stiction of the arm in this condition. The first LT I got was the L1000, and I knew nothing about the arm's actuation. I discovered that the single roller in the rear also was serving as the arm's damper, using the shearing of silicone damping fluid. Unfortunately, I only discovered this after my cock-up. Thinking it was congealed lubricant from the roller bearings, I cleaned it out. That arm flew across the table. I learned my lesson--get the service manual before you eff with it! I had to mix several weights of fluid until I got the right viscosity to achieve proper damping.

 

[Professor Bizzt]

PL-L1000 & PL-L1000A differences

I wasn't as impressed with the 1000A. If you say the motor is an improvement, I'll take your word for it. I consider it inferior due to the fact that the bearing is in the rotor and not in the stator, which removes any sort of reservoir for the motor's lubricant. I had heard it mentioned that the 'A' was fitted with a carbon fiber tonearm. Mine is definitely not, it is black painted metal. From a convenience standpoint, i much prefer the rotary shuttle to the pushbutton one.

It is written that the Buddha once said: "Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense."

My words are nothing. Your validation is everything.

Your PL-L1000 and PL-L1000A dissection project awaits you. When you learn for yourself what I have already said in my posts here, I am confident your intellectual honesty will encourage you to post your revised impressions here for all to benefit from.

Your discovery that the PL-L1000 and PL-1000A both utilize an inverted main bearing known as a Stable Hanging Rotor and that both main bearings have no lubricant reservoir in the conventional sense will be enlightening to those confused by now.

Perhaps your PL-L1000A tonearm will finally reveal itself to be constructed of a Polymer Graphite sheath and aluminum tube core coaxial composite pipe, and not some cheap painted aluminum tube impostor.

Finally, the acknowledgement that some actually prefer the newer two-speed arm queing buttons to the PL-L1000's rotary jog control, and that which one prefers is entirely a matter of preference and is not in any way an absolute, will also be refreshing.

Of course there is the possibility that you may have some odd and rare example of an early PL-L1000A outfitted with an old PL-L1000 painted arm (shame on Pioneer!), but I highly doubt that. You may also have a PL-L1000A hodge-podge of PL-L1000 parts. None of us here can know this from a distance.

Facts are indisputable, powerful, and immortal when acquired with painstaking relentless diligence and adherence to truth.


Best wishes, Professor Bizzt

 

[Professor Bizzt]

Sony PS-X800 & PS-X555ES diferences

Thnx much for comments re PS-X800. Perhaps the PS-X555ES might be a more sensible choice for simpler implementation.

Perhaps one way for you to begin to make a decision regarding simplicity of design between the PS-X800 and the PS-X555ES, is to analyze the pictures I posted of the internals of these two models in the gallery section of the Vinyl Engine.

As of now, I cannot comment factually on the PS-X555ES as I have not begun to work much deeper on it than removing the tonearm cover. I prefer to have my facts straight before I contribute thorough commentary.

I will say this though; I don't understand those that claim that the PS-X555ES is more difficult to work on than the PS-X800. To me (at this early stage) it appears to be easier.


Best wishes, Professor Bizzt

 

[kotofei]

Professor,

Thanks a lot for this very informative thread.

I own a Mitsubishi LT-30 turntable and enjoy her a lot, both sonically and aestetically. I also think that LT-30's carriage, tracking and tonearm position mechanisms were designed in a very simple way, allowing repairs to be done by an average person.

If you have run into an LT-30, it would be very interesting to know your opinion about this TT and how she compares with other Japanese DD linear trackers.

 

[Pio1980]

Perhaps one way for you to begin to make a decision regarding simplicity of design between the PS-X800 and the PS-X555ES, is to analyze the pictures I posted of the internals of these two models in the gallery section of the Vinyl Engine.

As of now, I cannot comment factually on the PS-X555ES as I have not begun to work much deeper on it than removing the tonearm cover. I prefer to have my facts straight before I contribute thorough commentary.

I will say this though; I don't understand those that claim that the PS-X555ES is more difficult to work on than the PS-X800. To me (at this early stage) it appears to be easier.


Best wishes, Professor Bizzt

I based my speculative musing on your photos of the two Sony examples in your care.
TVK has gotten it wrong in at least one other instance comparing the Technics SL-7 to the SL-10 IIRC, (quote)"The SL-7 is an SL-10 sans built-in MC preamplifier, <-snip->". The only parts they share are the arm tracking belt and tracking motor, nothing else. The SL-7 appears a complete rethink/simplification down to it's circuit board, heavy BMC base, and 2-phase planar spindle motor.
Regardless, based on your impressions and statements I'm looking harder at the PL-L1000/1000A as the most practical, robust, and interesting choice, my only theoretical reservation at this point being some concern regarding bottom chassis flex vs security of rigid alignment of the platter/motor assembly to the arm carriage assembly.

 

[Daniel Walte]

As a owner of a pl-1000a. I bought in germany in 1985. i believe I can attest that it does have the black polmer graphite arm. The arm pickup is done by a small motor and a o-ring type of <rubber band>. Mine has loosened and i have bought a replacement but until it snaps I have firmed it up by shims. The turntable has always performed flawlessly since i bought it new and is one of 3 I own. Turntable jukie i am. It was probably the best $450. investment i made in audio equipment. I have heard they were going for upwards of a $1000.

 

[Professor Bizzt]

Mitsubishi LT-30

Professor,

Thanks a lot for this very informative thread.

I own a Mitsubishi LT-30 turntable and enjoy her a lot, both sonically and aestetically. I also think that LT-30's carriage, tracking and tonearm position mechanisms were designed in a very simple way, allowing repairs to be done by an average person.

If you have run into an LT-30, it would be very interesting to know your opinion about this TT and how she compares with other Japanese DD linear trackers.

Hello kotofei,

I have not yet worked on a LT-30, but I would love to. I find them intriguing from what I have read about them.

The tonearm looks very similar to the Yamaha PX-2 and PX-3 except that the pipe is made of stainless steel, and of course that is a stiffer material than the aluminum used in the PX-2 or PX-3. I wonder if Yamaha and Mitsubishi both had their tonearms made by the same OEM (if an OEM was used at all)?


Best wishes, Professor Bizzt

 

[Professor Bizzt]

PL-L1000A Polymer Graphite tonearm or not?

As a owner of a pl-1000a. I bought in germany in 1985. i believe I can attest that it does have the black polmer graphite arm. The arm pickup is done by a small motor and a o-ring type of <rubber band>. Mine has loosened and i have bought a replacement but until it snaps I have firmed it up by shims. The turntable has always performed flawlessly since i bought it new and is one of 3 I own. Turntable jukie i am. It was probably the best $450. investment i made in audio equipment. I have heard they were going for upwards of a $1000.

Hello Daniel,

Thank you for verifying the use of Polymer Graphite in the tonearm of the PL-L1000A and confirming its desirability.

You should be able to purchase the correct queing motor drive belt from MCM Electronics. No point in suffering needlessly with short lifespans on your queing motor belt.


Best wishes, Professor Bizzt

 

[Professor Bizzt]

PL-L1000 and PL-L1000A plinth rigidity concerns

Regardless, based on your impressions and statements I'm looking harder at the PL-L1000/1000A as the most practical, robust, and interesting choice, my only theoretical reservation at this point being some concern regarding bottom chassis flex vs security of rigid alignment of the platter/motor assembly to the arm carriage assembly.

Hello Pio1980,

Yes, both the Pioneer PL-L1000 and PL-L1000A use a somewhat flexible ribbed plastic pan for a plinth and both pans are almost identical.

Having said this, many audiophiles would probably immediately toss the idea of using one of these, yet users enjoy them. So what is going on here? Let's stop for a minute and ask at least some of the right questions so as to get some useful answers.

What exactly is the responsibility of the plinth?
How rigid does it really have to be?
How much inherent damping should it have?
How massive does it need to be?
What distribution should the mass have?
Does it need to have a suspension?

I'd like to let these questions hang in the ether so it will tax your thinking the way it has mine. It will be fun to see what everyone comes up with. I'm confident the answers will push the understanding of the PL-L1000 and its close relatives to another level.


Best wishes, Professor Bizzt

 

[Pio1980]

Hello Professor;
The plinth hopefully provides a sonically inert, stable, and secure platform for the playback components. It should be sufficiently rigid to ensure consistent proper alignment relationship between arm axis/traverse plane and platter surface plane under normally encountered conditions. Damping should be sufficient to suppress resonances and microphony. Mass should be sufficient to suppress acoustic LF/feedback and seismic VLF interaction with pickup arm/cartridge LF resonance. Mass distribution is usually balanced to be equal on the support footings. Requirements/need for suspension are dependent on environment of use plus above factors subject to basic philosophy of a given designer, there is a world of difference between a Cotter 3-point suspension and what is generally done with an ambitious direct drive "Statement" TT.
Then again I could be way off-base on any/all of the above.


FWIW, it appears I may have just committed myself to a Pioneer PL-L1000 and a Mitz LT-30 needing TLC. When it rains---.
Now, about those mods for the Pioneer 1000 LTs and whether they bring the 1000 up to the mod'ed 1000A's level? See e-mail.
Best! Pio1980.

 

[Pio1980]

A couple interesting refs re Mitsubishi LT-30 details;
Marketed as DIATONE LT-3 in Japan.
http://audio-database.com/MITSUBISHI-DIATONE/player/lt-3-e.html
Arm described as stainless steel.

Restoration project shared on AK;
http://www.audiokarma.org/forums/showthread.php?t=298682
It should be noted that despite cursory appearances the components are not mounted on the MDF, rather instead the large alloy casting of the main unit.

 

[Professor Bizzt]

PL-L1000 and PL-L1000A modifications

The plinth hopefully provides a sonically inert, stable, and secure platform for the playback components. It should be sufficiently rigid to ensure consistent proper alignment relationship between arm axis/traverse plane and platter surface plane under normally encountered conditions. Damping should be sufficient to suppress resonances and microphony. Mass should be sufficient to suppress acoustic LF/feedback and seismic VLF interaction with pickup arm/cartridge LF resonance. Mass distribution is usually balanced to be equal on the support footings. Requirements/need for suspension are dependent on environment of use plus above factors subject to basic philosophy of a given designer, there is a world of difference between a Cotter 3-point suspension and what is generally done with an ambitious direct drive "Statement" TT.
Then again I could be way off-base on any/all of the above.

FWIW, it appears I may have just committed myself to a Pioneer PL-L1000 and a Mitz LT-30 needing TLC. When it rains---.
Now, about those mods for the Pioneer 1000 LTs and whether they bring the 1000 up to the mod'ed 1000A's level?

Hello Pio1980,

I'm a little worn out today, so commenting in depth on plinth design will have to wait. What you say here shows that you understand the role of the plinth very well. Thank you for helping everyone to further their knowledge on this subject.

The modification kits I offer for the Pioneer PL-L1000 and PL-L1000A is a tonearm mod, plinth mod, and suspension mod.

The tonearm mod is a rigid rectangular counterweight replacement that drastically increases inertia in the roll or torsional plane and moderately increases it in the yaw or lateral plane. The pitch or vertical plane is mostly unaffected so that warp issues are minimally impacted.

The result of this is much tighter and higher resolution sound and a significant reduction in the influence of the tonearm structure competence downstream of the vertical bearings. Therefore other mods downstream of the vertical bearings including the plinth become less mandatory and the problem is dealt with much closer to the source.

The plinth mod is a precision cut and drilled add-on (from the bottom) supplemental plinth in your choice of 1/4" aluminum or ceramic. Both plinths have all the necessary holes for rigid attachment as well as ventilation for both the PL-L1000 and the PL-L1000A. This design rigidly couples the main motor housing to the tonearm assembly and addresses rigidity concerns thoroughly. This supplemental plinth can also function as the sole plinth if one chooses a more ambitious route to eliminate the OEM plastic pan plinth entirely. The same supplemental plinth is usable on both models.

The suspension mod replaces the stock (and usually disintegrated) rubber spring seat/damper boots with a long-life neoprene spring seat. This seat can also function as an adjustable shim when more than one seat is used per spring. No damper is provided.

I have already installed two of these kits and I might be able to provide you with the contact info of the recipients (one of whom is an Audio Karma member) of these kits for purposes of verification of my work quality. If anyone is interested in these mods, they should private message me as it would be inappropriate and in poor taste to commercialize this thread or discuss this any further here.


Best wishes, Professor Bizzt

 

[Professor Bizzt]

Mitsubishi LT-30 tonearm pipe material

A couple interesting refs re Mitsubishi LT-30 details;
Marketed as DIATONE LT-3 in Japan.
http://audio-database.com/MITSUBISHI-DIATONE/player/lt-3-e.html
Arm described as stainless steel.

You are right Pio1980 and I was wrong because I trusted this info to memory instead of looking it up again before I commented. The Mitsubishi LT-30 tonearm pipe is not made of titanium, it is stainless steel. Sorry all, I try to be correct as often as I can. I'll correct my post ASAP.

Nevertheless, stainless steel in any alloy is still a stiffer material than the aluminum used in other tonearms.


Best wishes, Professor Bizzt

 

[Pio1980]

It was the Mitsubishi/DIATONE LT-1 with a Titanium pipe arm.
http://www.thevintageknob.org/THEVAULT1/LT1/LT1.html
http://audio-database.com/MITSUBISHI-DIATONE/player/lt-1-e.html
It would be nice to see the internals of this one to compare to the remarkably similar '3.