Phono stage revealing limitations of cartridge?

Hi,
I just purchased an Ear 834P for my system. This is my first experience with tubes. I hooked it up and I immediately noticed an improvement over the stock phono stage on my integrated. There was a much more three dimensional presentation. However, after listening for a few minutes, I realized the sound was very thin, light on bass, and the highs were bright and grating. Also, the output of the Ear is really high, so much so that the volume knob on my amp is almost all the way at the bottom and moving it very slightly results in a dramatic increase in volume. I'm wondering what is causing the bright sound. Here are the possibilities I've come up with:

1. The Ear 84P is just revealing the limitations of my cartridge which the stock phono stage had just smoothed over.

2. The stock tubes in it have gone bad. (I'm planning on trying out some Jan Philips 5751's on it to see if that lowers the gain a bit.)

3. The unit is defective/the person that modded it screwed something up.

4. I'm getting some very low level RF interference. You can't here it at all when music is playing, but if you turn it up all the way you can hear it. Perhaps this is causing the brightness.

5. The Ear and the Rotel integrated are a mismatch.

I've tried using a different cable from the phono to my integrated and that didn't change anything. I also tried using a different input on the amp. I tried both MM and MC to confirm that I am using MM.

Does anyone have any suggestions? I'd be really grateful if someone could help me get this sorted out. I know there's a lot of questions here, but I thought tubes would result in warmth, not brightness!!!

BTW, my system: VPI Scout/JMW-9, Sumiko Blue Point No. 2 (2.5 mV), Signal Cable Phono Cable, Ear 834P Deluxe Phono Stage (modded but w/ original tubes), Rotel 1062 Integrated Amp, Blue Jeans speaker cables, Infinity 3500 speakers (circa 1981)