Setting VTA on a new Shelter 901?

Viridian, I do not think you disagree with the “imagingability concept” but rather you’re trying to expand the said. Yes, at the correct VTA setting the surface noise become the orders of magnitude less annoying but this it not a reason but a consequence of something else. When “imaging” (as a correct PATTERN of phase randomonization) kicks in; when the X-force (I intentionally left without explanation what it is) embraces the musical messages and opens a communicative bridge between a musical event and a reproduced Reality; and when some other parameters of sound reproduction are set “correctly” then a specific mechanism get activated that tune a listener’s consciousness out of the external irritators and make the surface noise “reproduced in a different plane”. So, a minimization of noise is a process that flows out of something else. Besides, there are many other ingredients that affect a perception of a surface noise… There are some phonostages (assumedly they all have equalized input R and C) that make a cartridge to reach the best imagingability (Please, remember I said that “imaging” was VERY loaded word) and a less-annoying “plane” of surface noise at the different points/heights (there are some mechanism how a noise reduction could be done inappropriately-electronically) However, there is no free lunch and along with noise reduction those phonostages fuck up something else musically. I have seen those examples again and again…. So, what I propose is that the noise flipping in a different “plane” is one of the properties of the “Correct VTA” but this is not NECESSARY THE SIGN that a cartridge is in the correct VTA point.

Thanks for all your tips and comments.
I'm still breaking-in...just reached the 20 hour mark on my Shelter 901. But I have found a really sweet spot in my slowly increasing VTA adjustments. Having started at about 1.5° down at the rear, and adjusting my SME IV.vi in 1/8-clockwise increments, I'm now just a tiny hair from dead flat (cartridge bottom relative to record surface)...with probably a bit more to gain in treble smoothness.
But I think I'll wait till the 50-hr. mark before further "+" VTA tweaks.
Cheers, all.

Nnauber- This is revealing to me, since I have a 501 MkII with about 40 hours on it, thus far. I started with the VTA about the same 1.5 degrees "butt-down", upon general recommedations from others. I have since raised the VTA of my Nottingham Spacearm just a silver at a time, increments of about 1/64 of a turn on the adjusting screw, until I am a cat's whisker or two below flat-level. Sounds sweet but I, too, will wait until about the 100 hour mark before trying to get any finer with the adjustment.

4yanx,
Your comments are revealing, as well. My 501/II has about 35 hours(Oscar P. & Ray Brown are working on hour 36 as we speak!), and I'm relishing every nugget of info in this thread. My Spacearm is set about flat for now, and I'm also going to wait until 100 hours before I tweak it much. With this arm, I haven't yet figured out the best way to adjust in an ideally methodical fashion.

Anybody finding phonostage impedance settings having affect on break-in and/or? I recall someone suggesting to go w/setting at 47k until about 100 hours, then switching down to the recommended 100 ohms. Mine's been at 100 ohms all along. Thoughts?

100 ohms is where it should be. Also a hair down in the back, just like 4yanx says. The cartridge is broken in after 40 hours. There is no need to wait beyond that for making your final adjustments.