Hi all,
Separate from any perceived cartridge safety issues relating to failure modes of linear trackers, I think that the curious audiophile (one who is mechanical and handy) will get a real kick out of owning an ET-2 for 6 months to a year.
This arm could up being a "keeper" arm for you. I have to wonder how much better an Air Tangent or a Kuzma really is than an ET-2. I suspect that the order of magnitude will be on the order of a shift from a Schröder Model-2 up to a Reference ... just a guess.
Upon initial inspection, the arm looks to be flimsy in several areas. Bruce T. did a masterful job in designing this arm however, and the whole is FAR GREATER than the sum of its parts.
Of course, in buying an arm like this used, it may likely have changed hands numerous times. There are a few screws which are threaded into the composite material, and a careless user may have stripped some of these.
None of this is intended to scare you off. I have not performed heavy research on replacements for the Wisa pump, but the information is out there on the web for those so inclined. I've never been inclined to run an air tool compressor in the garage to run mine, although I had installed an air regulator along with a higher (30 psi) pump.
In answer to one question - Yes, I ran a filter and a surge tank with my rig.
I think that Bruce is correct in that the higher pressure doesn't do much here, but bear in mind that I've made numerous improvements in my turntable design in the three years since I owned this arm. Perhaps I would hear a greater improvement today if I were to compare standard (3-4 psi) pump with a higher pressure pump (30-35 psi).
One experienced user I know commented that with arms having the higher pressure manifold, as you increase the pressure to the 30-35 psi range, that there's some "blow back". As the stylus reaches the runnout groove, it gets pushed back toward the beginning of the record - of course skippin as it moves.
I never exceeded 25 pounds, due to the amount of pressure that my regulator bled off.
He comments that orienting the arm laterally so that it doesn't get as close to the exit solves this. The problem is that you don't have much of lateral travel adjustment to work with. I think this borders on the extreme behavior side of things.
I never experienced extreme angst when using the arm, but the idea of having 35 grams of lateral mass decide to stop moving did cause me to take pause.
Worse I think than the horizontal limitation (where you'd experience skipping over the same groove) would be the arm freezing up in the vertical plane - when coupled with a record that is warped. I can envision a bottomed out cantilever. With a design like the ET-2 if the arm were to freeze in place, it would stick in both planes of movement.
Now, the field experience tells us that this is all a minimal risk. Perhaps I'm a weenie.
The new owner of an ET-2 should perform a practice setup with a DISPOSABLE cartridge. Your first try at getting perfect level will be an experience you will not forget. Leveling with a bubble level should be considered as a first (and very rough) approximation. The arm itself is the best device to use as a level.
Cheers,
Thom @ Galibier
