Hi, Eastsideguy: I'm a fellow Seattle resident, so you are welcome to contact me and we can talk about your problem. So you know, my analog front end includes a Rega RB900 arm with a Grado Reference cartridge, so I have some familiarity with your setup.
You may have a combination of factors that are causing the symptom you describe. Here are some general comments to think about before we talk:
1. As others noted, the vertical tracking angle is important, but only a seriously out-of-whack setup would account for the severe symptoms you describe. The Rega arm can be raised using spacing washers, and I have a set that you are welcome to try (I don't use them).
2. The procedures you used to set the tracking force and anti-skate aren't the best methods for the Rega arm. The best results will be achieved if you set the Rega's tracking force gauge to the maximum (3 grams, I think). This may seem counter-intuitive, but the maximum setting actually disengages the tracking force spring. Then, set the tracking force using a decent gauge, such as the Shure balance-beam gauge which you can buy for $20 (or you can borrow mine). To set the anti-skate, I usually use a vinyl LP that has a special grooveless section. To adjust the anti-skate, you place the tonearm down on the record, and watch to see if the tonearm skates inward (toward the center) or outward (toward the edge). You simply adjust the anti-skate force until the tonearm remains stationary while the LP is rotating. You are welcome to borrow a test LP from me that has one of these grooveless sections. I must tell you, however, that having a bit too much or too little tracking force and anti-skate would not account for the severe lack of highs that you describe.
3. The tonearm wiring in the Rega arm that comes with the P3 isn't the best, nor is the counterweight. You might want to consider the "mod" available from Expressimo Audio, which includes upgraded tonearm wiring and their "HeavyWeight" counterweight. I recently bought the "HeavyWeight" counterweight, and found that it made a very significant improvement on my RB900 arm. I'll give you more detailed comments about these mods if we talk.
4. The problem you describe -- specifically, the lack of highs and air -- sounds to me as though there is a cartridge impedance mismatch. You did not state what cartridge impedance setting your preamp has, so I suspect that may be the main problem area. The Grado cartridge is a moving iron design, and they usually work better when they have an impedance similar to a moving magnet design. I suggest you check the cartridge termination in your preamp to be sure it is compatible with the Grado.
If you'd like to talk by phone, drop me an E-mail with your phone number and I'll be glad to call you tonight after work, or this weekend.
Best regards,
Scott C-
