At what vol level do you get rumble / flutter?

I meant to mention it in my last post - if anyone saw Fremer's "21st Century Vinyl" DVD, there was a great segment shot at Stirling Sound in NYC, and interview with the recently deceased, great George Marino. (What a loss to the community, by the way. Left us way prematurely. RIP George.)

Stirling uses a Neumann lathe to cut the master disc, and Marino was explaining the importance of isolating the lathe as it's essentially a turntable with a cutting "stylus," and any extrinsic noise can easily get transferred through the cutter and be embedded in the disc together with the recorded sound. They have the lathe on a slab of concrete and spring suspended. Even with this, I'm not sure you can isolate anything in Midtown Manhattan where Stirling is located, and it is certainly possible that many cutting lathes are not perfectly isolated and thus some of that unwanted low frequency noise does make its way into the vinyl.

@johnny, my table is at my dealer now. It has the lighter 65g counterweight for cartridges between 4-7 grams. How do I calculate the effective tonearm mass with this lighter counterweight (10g lighter that the factory 75g for 7-12g cartridges). I might have him put in a pair of 1 gram brass screws to bring the weight up a little.

I forgot to mention my turntable is on a custom steel wall rack bolted to the studs in my house but is in an audio cabinet (no doors). The section of the audio cabinet that houses the turntable has some of the back panel removed so the steel rack arms can come through. Could my problem be caused by this setup?

BTW, I put a new Vincent Pho-8 up against a new Pro-ject phono tube box II (my demo one was replaced under factory warranty after 1 channel got noisy) this weekend. The Pro-ject won out with better sound stage, realistic instrument sound and just overall more musical. I hope to upgrade the wall wart for the Pro-ject tube box. Would this one be a higher quality less noisy power supply?:

http://www.powerstream.com/EA1050.htm
EA1050A-61 16V 4A 5.5x2.5x11mm $57.50

Thanks everyone,

Scott

I added a pict of my entire system (on my system page) to show the config. Turntable is in the upper right corner.

07-18-12: Sbrownnw
@johnny, my table is at my dealer now. It has the lighter 65g counterweight for cartridges between 4-7 grams. How do I calculate the effective tonearm mass with this lighter counterweight (10g lighter that the factory 75g for 7-12g cartridges). I might have him put in a pair of 1 gram brass screws to bring the weight up a little.

The change in counterweight doesn't change the effective mass of the tonearm. Effective mass is only the weight of the tonearm from the pivot point forward to the headshell. Once the cartridge is mounted, total effective mass includes the effective mass of the tonearm plus the headshell if removable, the cartridge, and mounting hardware. Standard mounting hardware is about 1/2 gram. Since cartridges have a wide range of weights, you use a heavier counterweight to balance a heavier cartridge. The heavier cartridge increases effective mass; the heavier counterweight does not; it simply enables you to get the desired tracking force from a heavier cartridge.