Top linear trackers


I’m in the market soon for a linear tracking tonearm. Two in particular have piqued my interest, the Kuzma Airline with damping trough and the Bergmann Odin. From what I can tell, these designs have especially benefited from lessons learned during the evolution of linear tracking, incorporating features like longish tonearms to minimize warp wow, ultra low friction, low air turbulence, and mitigation of the high horizontal mass issue by use of a damping trough (not sure of the Odin on that). The Odin is known to have a very quiet pump. The lift on the Kuzma may be easier to operate. I would love to hear from anyone with long term experience with these arms or comparable other ones. I would be mounting this on my current VPI Classic 4 and most likely using my Soundsmith Sussoro Mark 2 ES. That cartridge should work with either arm based on the resonance calculations. Down the road I may consider moving the arm to a Sota Cosmos Eclipse or a Technics custom SP10R or another high value setup. I cannot afford the Bergmann Galder with Odin. If I could I probably would have reached the end of my journey.
earthtones
I lucked into a Mitsubishi Vertical Linear Tracking TT, LT-5V, love it, sounds great.

This one listed here is a beauty, original box ... looks perfect, both oem headshell and new one with cartridge

https://www.audiogon.com/listings/lisa6c4e-mitsubishi-lt-5v-with-b-o-mmc-20-cl-turntables?refsource=...


this one probably needs cleaning and new belts, not hard if you are generally handy, no special tools needed. risk other things not needed.

https://www.canuckaudiomart.com/details/649677871-mitsubishi-lt5v-vertical-turntable/

and it’s cracked dust cover replaced (after-market ones exist), clear or bronze, however OEM logo missing

https://www.ebay.com/itm/183632411501




I've owned an ET.2 (upgraded to 2.5) for close to 30 years, there are several fairy recent improvements as well and Bruce is always there for support.

The Trans-Fi is suppose to be a giant killer.
Dear @earthtones : You have at least other very good alternatives with Thales, Reed and Shoroeder that designed pivoted tonearm that are linear trackers. 

Regards and enjoy the MUSIC NOT DISTORTIONS,
R.
@rauliruegas those are interesting options. I'm most intrigued by the Schroeder design which looks simplest. The Thales would appear to suffer from skating seen in conventional pivoted arms, due to the headshell being offset as it traverses, albeit with a changing offset. The Reed requires a battery and Michael Fremer wasn't impressed with its bass performance. Fremer couldn't fault the Kuzma as long as the dampening trough was used. I understand that it is cartridge dependent. My low compliance Soundsmith looks to be well suited. I need to see a review that directly pits the Schroeder against the Kuzma. Also, I'm not sure if I would give up anything that I'm currently getting with my SME 312S. Yes, it's got the extra length for lower tracking error, but I still hear inner groove compromises so that's why I'm looking seriously at linear trackers.
Thanks everyone for your responses. It makes for interesting research! I'm hell bent on eliminating the curse of standard pivoted arms. 
earthtones
I’m hell bent on eliminating the curse of standard pivoted arms.
What curse is that? Before you answer "tracking error," why not audition an underhung arm? If you do, you might find it difficult to believe that a pivoted arm’s tacking error is even remotely audible.

What arm are you using now?
I like the idea that linear tracker tonearms follows the groove the same way it was originally cut vs the pivot tonearms with only 2 null points thus introducing distortion, although many/most may say they cannot hear the difference. Because orchestra music often ends in a crescendo, I like the idea to hear it without the possible pivoted tonearm distortion.

Regarding air linear trackers, because Fremer described his dislike of past LT as the arm “chattering” along the track - thus I have zero interest in mining old/used designs. The new modern air LT tonearms are so much better in engineering, tolerances, materials, and manufacturing. But air LT adds more complexity with the pump, hose, track, and future maintenance.

The Thales LT uses 2 parallel arms to keep the cartridge aligned with the groove. Tuning 2 arms vs 1 and introducing more pivoting points adds to the complexity, friction, and may introduce more problems.

The Reed 5T uses a laser/electronics to move/keep the cartridge aligned. If this complex design needs future maintenance....

For LT, I currently favor the Schröder LT tonearm for it’s simplicity and Frank’s reputation in tonearms. The drawback is that reviews are practically non-existent. My baseless guess is that because Frank already has his hands very full making/selling his other tonearms that he has little/no interest in further marketing/selling his LT tonearm.
I’ve used the Airline as my main tonearm since around 2007 or so. It replaced a Triplanar which was mounted on a Kuzma Reference turntable. The Airline has been used with the much heavier Kuzma XL.
The arm itself is extremely well fabricated and I have had no issues with it whatsoever. Set up is pretty easy too, once you become familiar with its behavior. I’d say the biggest drawback is the need to use a fairly substantial air compressor. The one supplied with the arm- a Sil-Aire made in Italy-- is a quality compressor, quiet as far as those things go, but you don’t want it near the listening room. I’ve experimented with several different compressors, not because of sonics but simply because I wanted to minimize the amount of time I had to spend dealing with it. The larger compressor tank will hold more air (at one point I was running one with a 13 gallon tank), but requires more time to fill when the motor kicks on.
Sil-Aire has a facility here in the States and they’ve been great to deal with over the years- they know these things inside out, though they are not audiophiles and use on a tonearm is one of many different applications for these things. Right now, I’m using an oil-less medical grade unit which has a tiny tank made of stainless and is 10db louder than the oil-based compressors. I had built a silencer box for a larger compressor, and this fits into it. I’m running a good distance of air hose through the walls to get to the point of use where I have a set of filters for particulates and oil that the compressed air (@ 65psi) must pass through before reaching the arm.
In terms of maintenance, I clean the shaft along which the air bearing runs with lab grade alcohol wipes to make sure there is no lint or room debris on the shaft. I’m told this is not necessary, but it makes me feel more confident that the path the bearing is running on is clean. If you go to this link, and scroll through it, you will see the arm and the compressor with silencer box. [url]https://thevinylpress.com/system-notes-austin-2017/[/url]
Kuzma support in the States is extremely good if you are located here, due to Scot Markwell, a well regarded person in the industry. If you have reason to call the factory in Slovenia, you can also speak to Franc, who is courteous and unfailingly helpful.
The only cautionary note I would make is that in your effort to eliminate some perceived compromise in a conventional arm, you are taking on a whole other set of operating parameters. Though I’ve had zero issues with the arm, I had never planned to be a compressor mechanic. I’m getting pretty good at it. :)
Just had a wonderful time listening to some of the best sounding music ever, only to learn to my surprise the whole time I was beside myself with pleasure I was in reality cursed. Damn that pivoted arm! Its so cursed it cast a spell making me think it sounded good! Unbelievable. And the only way out of this curse is the joy of running an air pump. But I wonder, which one? I know! I'll ask a bunch of random dudes!

On second thought I'll stick with the Conqueror. Curses. Foiled again. 
Most of my music listening is classical and unfortunately I prefer large scale symphonic pieces that of course tend to have crescendos right where you don’t want them in the inner grooves. Dave Chesky understood this well and wisely avoided the inner grooves. Maybe a handful of my LPs at most don’t portray at least a constricting effect, if not outright distortion, in the inner grooves, and that’s with a properly set up SME 312s. The degradation is subtle but it is there. If my digital rig weren’t so good and the rest of my system not as resolving, I wouldn’t be as concerned. Every review of a good LT I’ve read says that it’s a revelation to hear the ease of reproduction all the way to the end that’s not possible with the pivoted arms they’ve had. I’ve invested way too much in my analog rig to not give this a shot.
3 generally recognized null point variations

http://www.dvautier.com/nullpoint/null.htm


favor your inner grooves

Stevenson reduces distortion by favoring the inner groves which may be more compact and more in need of good alignment.
I’m not about to claim that all linear trackers are better than any and all pivoting arms.  That would be silly.  What I can say is that compared to the well set up pivoting arms that I have used over the years, Sumiko MMT, Grado, Sumiko MDC800, Alphason, SME IV and SME V, going to my still current ET2 linear tracker was a revelation.  According to what are my sonic priorities, no contest.  Especially on large scale orchestral recordings; and, yes, superior performance in the inner grooves.  Highly recommended and good luck.
Millercarbon, maybe your ecstatic mood is induced by your various PHTs placed strategically here and there.
I have not made direct long term comparisons between the Airline and a conventional arm on my set-up due to the inability to get the Minus K to balance correctly with the additional weight (30 lbs) of a second arm pod and the requirement of a single center of mass to get the Minus K to "float" as it should. My judgment of sonics attributable to the linear arm (which I did not comment on above) may also be influenced by the fact that I went from a very good self-isolating table (the Kuzma Reference) to a very high mass table with no suspension (the XL). That said, what I hear is rock solid images in a very spacious presentation with no noise (unless there is some flaw in the particular pressing). I can best describe it by saying that you notice no "halo" around the sound coming from the turntable-- something that is most noticeable when it is absent.  Whether that is solely attributable to the arm, or the combination of the arm with the very high mass table is not clear.
The Airline (and this may hold true for the ET2 as well) also seems to like a lower compliance cartridge. After years of running the usual high-end Lyra and Airtight cartridges, the synergy with the Koetsu stone bodies has given me the best sound I've ever had from this system. That cartridge change has also rectified one of my chief complaints about the sound of my system- the lack of convincing, deep bass, which is often a complaint about these arms. On double bass, or the lowest registers of a concert grand,  I now get a fully fleshed out image that not only has real gravitas, but also the sort of dimensionality in the bass for which the Koetsu is best known in the midrange. These qualities keep me soldiering on despite the complications of running this high mass rig in an old house with springy floors and air hoses and compressor. Perhaps when our current health crisis subsides, you can make some meaningful comparisons and judge this for yourself. 

Dear @earthtones : " Yes, it's got the extra length for lower tracking error, but I still hear inner groove compromises so that's why I'm looking seriously at linear trackers. "

Unfortunatelly and especially with the whole analog rig always exist trade-offs.
If it's real that a longer tonearm has lower tracking error it's true too that the cartridge/tonearm alignment must be super accurated because a minimum inaccuracy rpovoque even higher errors that in a shorter tonearm. In the other side in a longer tonearm the developed resonances/distortions are higher than in a shorter one.

With linear trackers exist trade-offs too like the opnes you named and others and one of those " others " is in the bas range ( specialy inl low bass. ) where almost any pivoted tonearm but unipivots are second to none and superior to the LT.

Now, those inner grooves compromises with a good analog rig and a high resolution system as your can be put at minimum where you can't detect it for this you need a good damped tonearm and a a cartridge with good tracking habilites. I don't know if the 312S comes with a trough for silicon oil damping as the SME V, this helps to better tracking and lower resonances.

Now and even that your cartridge/tonearm frequency resonance  has no problem your cartridge is a low compliance one and bad tracker that shows normally at inner grooves.

The tracking error in the SME and other tonearms is really small for been or develops that problem. I that been the problem then the 98% of audiophiles that use pivoted tonearms always have your problem and in my case in the last 10-15 years I left to have that kind of peroblem. LT can't fix it because the trouble is in the cartridge maybe only the one you own not all SS Susorro samples.

I have several cartridges that runs in pristine way the Telarc 1812 LP that is the most extreme challenge at inner grooves.

So, I think that your problem is not exactly at the 312S but somewhere down there.

If you want to go a head with a LT then could be " healthy " to test it before buy it at your place with your cartridge.

Regards and enjoy the MUSIC NOT DISTORTIONS,
R.  
or could be that your tonearm sample is out of specs.

@erthtones you can try to contact directly Peter looking for adcvise about and in the other side with SME too.

Do you already tested other cartridges in the 312S?, I think that you could do it and see what happens.

Btw, what happens  when at the inner grooves of an LP ( Classical. ) there is no those normal climaxes? any trouble down there too?

R.


@rauliruegas I’m quite sure the tonearm is fine and I’ve run three different cartridges in it - a Benz Ruby 3, a Kiseki Purpleheart, and now the Soundsmith Sussoro, which by far tracks and reveals the best I’ve heard. It was a bit of a challenge aligning the cartridge since the SME paper alignment template is a joke, so I did quite well with my SMARTractor and adjusting the sliding base in an iterative process to get a Baerwald alignment spot on. (I’m not interested in Stevenson). Then I ran the Analog Magic software to help get the other parameters precisely dialed in. **There is no gross tracking distortion generally with my good records. Instead the soundstage gets slightly pinched or constricted**. To give one example of a great recording of mine that is however, compromised, on my well recorded copy of Paul Paray Conducts Ravel/Debussy, Mercury Living Presence reissue, one side has music well towards the center. It is there, for example, that the soundstage collapses and distortion rises moderately. This record plays tremendously until the last few millimeters! I know the grooves themselves may be limited and perhaps the engineer squeezed too much on one side. It is my hope that with a good linear tracker the range of excellent sound will be vastly increased. 
@earthtones : by coincidence I own that LP too and several others that are well towards the center.

I don't listened to that LP from years now I will try today and if I I have any trouble down there I will post it and if not I keep " quiet ".

With out listened yet and knowing my system I could think will be no trouble but.......we will see.

R.

Please no flamewars, just another datapoint. 

Versa 1.2 and VPI TNT 1 with 9" JMW arm with Benz LP sound the same. I was surprised expecting the Versa would outshine the VPI, but that was not the case. The Benz sounded wonderful in both VPI and Versa: very rich tonally which is my preference. LP is very detailed also but not as much as Goldfinger. Better than either is the Benz Gullwing which combines the lucidity of the Goldfinger with the calories of the LP letting you have your cake and eat it too. The cherry on top is that the Gullwing costs less than either LP or Goldfinger. There is no body like no body. Want to hear the new Ortofon Verismo which also has no body but the demand for that cartridge is high and I cannot get ahold of one. Always wanted an Ortofon. It is wonderful how these old companies continue to flourish: Benz, Clearaudio, Ortofon, Koetsu, Lyra, Kiseki. Of course nuttin' wrong with new companies. People can be so touchy.

(Comparing TNT with 9" JMW against recent Avenger with 12" printed arm again the same. No progress in twenty years, but both are great turntable/arms. In case you were wondering if the Versa/TNT comparison holds up after both types out of production since the last century.) 

Definitely consider the ET 2.5.  Bruce is still making them, but you need to order direct from him I believe.  He also has spares and does a great job on repairs and he's a pleasure to deal with.

Using the right combination of arm wand and leaf springs on the counterweight assembly, you can accommodate a wide variety of cartridges from moderately high compliance (such as Grado woodies) to low compliance cartridges.

I've owned mine since 2001 on my TNT4, and I would not consider replacing it.

This will not even register in your search radar, but as someone has mentioned the Trans-Fi Terminator should be on your list. 

Look at the manifold, an inverted ‘v’ as opposed to a circular tube in most other cases. It is an inherently more stable ( no tendency to roll ) platform for the cartridge / wand assembly to glide on. It is low pressure / high flow operating as low as 0.5 psi ( I run it at 1.25 psi ), which can easily accommodate surge tanks for elevated SQ and aquarium type compressors are more than adequate. And the value proposition is out of this world.

Please review discussion of this arm on another thread : 2019 update Trans - Fi Terminator. You will find users of other ‘higher caliber ‘ arms, LT or otherwise, moving to the Terminator. Most recently a Clearaudio TT5 user taking up the Terminator, resulting in the purchase of a second Terminator to boot!

While I use a linear tracking arm, I do not subscribe to the notion that one technology is superior to the other. It is in the implementation / execution. However, to find a matching pivot arm at Terminator’s price range is impossible.

@ledoux1238 I am aware of the Terminator and read a number of threads on it. Anyway, may I ask you: In your experience does the Terminator function better with lighter / higher compliance carts or the opposite?

@solypsa I am using a ZYX Ultimate Omega ( medium compliance, 12 ) and Audio Tekne MC-6310 ( med / high compliance, 20 ). These work very well with the Terminator.  My own experience has been limited to various  medium / high compliance cartridges. 

 

On a seperate thread, @terry9 reported that Koetsu RSP, 12g and low compliance, did not work with Terminator's aluminum arm wand. He then developed a heavier Panzerholz wand which then worked very well. And Someone is using a Clearaudio GFS, 16g, though med compliance. Due to Terry's experience, I have held off on venturing into low compliance territory. While I feel that the newer carbon fiber wand which I use should work with Koetsu's, I would think twice about putting a stone body Koetsu. 

 

 

Look at the manifold, an inverted ‘v’ as opposed to a circular tube in most other cases. It is an inherently more stable ( no tendency to roll ) platform for the cartridge / wand assembly to glide on.

Actually thats misleading. Although it uses parallel V extrusions which tend not to roll laterally, the Terminator uses a floating air bearing. If I hooked up a high pressure pump I could blow the arm off its rail. If there are any deviations in air flow this arm will bounce along the rail.

The Eminent Technology uses a far superior captured air bearing - the spindle runs through a manifold and air is forced around the tube applying pressure 360 degrees. This is far more rigid and stable - any deviation in air pressure at any point is met with a correcting force on the other side.

Not all "tube" air bearing arms are fully captured. Some have air holes only on the top side, which means there is no resistance to bottoming out.

I have an issue with arms like the Rockport & Kuzma where the air is forced into the moving arm - in my view this must play havoc with tracking force at a micro level because the plastic air hose will try to straight out under pressure, hence exerting vertical pressure on the arm.

With the Eminent Technology the air is piped into the manifold. There are no air lines connected to the moving arm/spindle.

@ledoux1238

If you really want to make a substantial upgrade to your front end you should investigate the Eminent Technology ET2/ET2.5 - even an old ET2 low pressure will trounce the Terminator - I’ve heard both - there is no comparison.

The ET has a decoupled counterweight system that can be tuned to the cartridge compliance - you can run anything on it from Decca's to high compliance Shure V15's.

 

@dover I am a big fan of Bruce Thigpen. I own a pair of LFT 8bs’. The initial idea for purchasing the Terminator was to use it as a linear tracking starter kit with the intention of upgrading to the ET-2.5s’. Well I haven’t gotten to the upgrade just yet. 

If you have compared both arms some years back and came to the conclusion of ET2.5’s superiority, then I would submit that the Terminator has also improved over the years. The new carbon fiber wand, a new brass manifold, an after- market arm base developed by the late Owen Young of NZ have all added to the Terminator’s improved SQ. And if  you discard the generic 1 gallon (4.5 liter) surge tank for a total air filtration volume of 150 liters, then it is a very improved Terminator that you might not have really listened to.

However, having said all that, I believe I will end up with a ET 2.5. I just do not look forward to experimenting with pump / compressor ( high pressure as opposed to low pressure of the Terminator) and filtration, not to mention just getting to understand the arm as I am a very slow learner.

@ledoux1238

For my ET 2.5, I use a shop compressor located in my garage. I ran an air line to my listening room (standard NPT 1/4" fittings) that runs into a water trap/filter and into a precision low pressure regulator. From there I have a barb that fits standard fish tank air line that goes into the ET manifold. I also run the pneumatic actuators on my VPI TNT 4 thru another precision low pressure regulator. Oh, and also an air gun for dusting off a third regulator. Once set up, there isn’t much to worry about other than cleaning off the spindle periodically. I run the ET at around 12-15PSI most of the time. Going higher doesn’t seem to improve the sonics, and can be problematic, as the pressure escaping the manifold can sometimes blow the spindle assembly back off the runout groove.

@vinylzone The ET arm can be made to order with an Alita 15 compressor according to its website. This is the compressor I am using for the Terminator. But I had thought that the ET is a high pressure arm, and the Alita operates in the 3-5 psi range. I use it to run the Terminator at 1.25psi. I am putting in an email to Bruce to start seriously start discussing a purchase. I am more comfortable running the ET in a lower pressure environment. 

@ledoux1238 , I am not sure why you want to run the ET in low pressure, unlike your Terminator, capture bearing arms, like the ET, usually perform better at higher pressure, at least up to the limit of the air bearing. This is due to higher pressure creates a tighter bearing. If I remember correctly, the ET2.5 high pressure bearing can accepts up to 15 - 20 psi. If I am using the ET, I will be using a high pressure compressor with integrated surge tank, and multistage air regulators. 

 

Dover has this interesting point about the air hosts in the Rockport / Kuzma Airline affecting the VTF! This is new to me, but while I can imagine the VTF can be affected if you are using say 10psi as compared to 30psi, I can't see why there is a problem when you have adjusted the VTF with the air pressure you will be using during play. But then, I suppose everything is possible if we are talking about the microscopic level. If there is a problem with the air host, I would think it is the lateral drag it created. So, it is very important to arrange the air host and wiring into a  n  shape to minimize drag.   

@thekong 

You are right about the potential drag.

Another significant advantage the ET has over the Kuzma, Rockport etc is the decoupled counterweight system in the horizontal plain. This lowers the horizontal effective mass as seen by the cartridge - significantly lower than the other options - and in actual fact lower horizontal effective mass than some of the pivoted heavyweights arms eg FR64S & Dynavectors.

 

Surely the Thales twin-tube tonearm achieves much of what linear-tracking arms set out to do, but without the inherent drawbacks of linear-trackers.

It seems to me that the biggest strengths of the Terminator are:

1. adjustability - everything is adjustable. All adjustments are intuitive. VTA and horizontality can be done on the fly. I would wish for more accurate adjustment of tangentiality, but no linear tracker is any better; I think. Azimuth is very precisely adjustable, but fiddly.

2. tweakability - It is easy to increase mass. It is easy to increase damping. It is easy to install a new wand, and not that complex to design one. It is a simple matter to build a second tower to support the other end of the beam, and incorporate a fine adjustment of horizontality. But this sacrifices easily adjustable VTA.

Likewise the greatest weakness seems to have been missed: vertical movement is allowed by two pivot screws which are set into two 90 degree vee’s. This junction is not inherently stable, but it’s stable enough for most records.

Conclusion: I own two, and consider them the best bargain in high end. One is on a Nottingham Analogue Mentor (updated to Dais standards), the other on a DIY air bearing which features an air cushion in all 3 dimensions. I’m hoping my DIY linear tracker will solve the T’s problems without introducing new ones, but hey, that’s DIY for you.

Hi twoleftears , while the Thales is an interesting design,  it has its own set of problems. It still has the skating force to deal with, and I am not sure if it is a good idea to have bearings so close to the cartridge. If I am in the market for a pivotal tangential arm, I'll be looking at something like the Schroder LT or the Reef 5A instead.

@thekong I am guilty of having no experience with high pressure LT arms. Hence I make assumptions based on my DIY experiences with the Terminator. One assumption is that air filtration is a very important part of an air bearing arm. And with the Terminator, the way to improve filtration is to increase the use of surge tanks. However, the more tanks / volume I add with definite SQ improvement,  I had to change / increase the output of the pumps used. Given this assumption, I had thought that with high pressure LT arms, one way to improve SQ is also to increase air filtration / surge tanks. But that may require even higher pressure pumps...etc. At some point the pump pressure will be too large for safe home use. Am I wrong with my thinking on high pressure arms? 

@dover Obviously you are right that a captive bearing works best with higher pressure. I got a message back from Bruce T. He says that the lowest pressure to operate the ET2.5 is 3-5 psi. The higher the pressure the stiffer the bearing.

I have one additional question and that is regarding pressure gauge. I see a lot of ET LT arm users place pressure gauges on the arm, right before the manifold. The reading on the gauge therefore reflects the pressure at the arm. However, I had thought that a gauge of any kind is also a disruptor of air flow. I place my gauge right after the pump, reading the pump pressure instead. And then allowing the surge tanks to perform their tasks down stream. Again, am I wrong in my thinking? Will a pressure gauge affect the air flow negatively?

 

@ledoux1238 

I have a pressure gauge, but to be honest I don't use it.

I have inserted it to check the pressure when I set the arm up or do a system check, but with the ET you can feel the pressure when you handle the arm. Here in NZ I use a moisture extractor prior to the entry to the arm because we have a humid environment and during winter when you have hold and cold patches, you can get condensation.

@ledoux1238 , I have used high pressure compressor with integrated surge tank for nearly 20 years and never had any problem! For my Rockport arm and pneumatic anti-vibration table, I am using an Jun Air compressor with a maximum output of around 120psi and a 25 liter surge tank. At this high pressure, unlike in your set up, the metal surge tank was purpose built and came integrated with the compressor. There is a regulator to stop the compressor when pressure in the surge tank reaches around 120psi. The compressor will automatically starts again when the pressure in the tank drops below a certain level. The compressor is quite loud when it runs, so it need to be placed in a separate room.

 

There is a regulator with gauge at the output of the surge tank for you to set the output pressure. I have another regulator closer to the arm to gradually bring the pressure down to around 32psi. The regulator I am using can be adjusted in 0.1psi steps. A difference of 0.1psi is clearly audible. 

 

I have never heard of the idea that the gauge disrupt air flow, but then I have no idea whether it would. I do not use any pressure gauge on its own, and always as a part of a regulator. 

 

another vote for the CS Port linear tracker. i own the CS Port LFT1 turntable which has the linear tracker. what is special is it’s low pressure low flow which results in amazing subtlety and nuance. and the air box is completely silent. great bass and rendition of space. and very elegantly made.

https://www.csport.audio/products/products-afu1-2-en.html

back in the day i owned other linear trackers; the Rockport Sirius II SE for a year, then the big bad epic Sirius III for 8 years, so i know me some linear tracker.

@thekong Thanks for that explanation. So pressure levels can reach 120psi! At that level,  it would make sense that all accessaries are purposefully built with fail safe mechanisms. 

@mikelavigne +1 on the CS Port arm. 

You were one of the very early adopters of the CS port system, certainly in the US; low pressure arm with non-servo motor, the exact opposite of the Techdas brute mentality. 

in September 2019, i did receive the first CS Port products in the Western Hemisphere. i contacted CS Port in Japan to inquire and they referred me to the UK distributor. it was another year before anyone else in the US bought any.

why i pursued it, was feedback from a friend in the UK who had been a fellow Rockport linear tracker owner 15 years prior. he knew i would appreciate it, and he was spot on. i listen daily with great pleasure.