Top 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.