Noise from Rega P3/RB300/Dynavector DV20X-L

you need the dv20x-H. the bias is a moving magnet cart with a high output, and your phono pre is expecting a stronger signal. the dv20x-l is a low-output moving coil cartridge, but the dv20x-H is meant to be of much higher output, so that it'll run properly in a normal MM phono pre.

H is for high
L is for low

or you could get an mc phono stage.

I think you are also running into an impedance mis-match there. The MM phono section probably wants a 47K Ohm load (which the 20 XH has), and the 20 XL is only 30 (NOT K!) ohms. Makes quite a difference in response & dynamics. Probably accentuates the noise floor as well as damping the dynamics.
Swap the cartridge if you can, or pick up an MC phono section & run it into a line-level input.
Good luck!
Ed

Thank you for all your responses. Forgot to mention that the Rotel RQ-970BX has a switch for both MM and MC. Its MC specs is .21mV / 100 Ohm. I am not quite clear on this - will it be a big mismatch if the DV20X-L spec is 30 Ohm but the phono pre is 100 Ohm?

I am thinking of replacing it with either the EAR 834P or Michel Trichord Delphini. Appreciate advise or share your experience.

It doesn't surprise me that you are still getting noise from the Rotel. Not to say that it isn't a good phono preamp, but it costs a lot more to build a sufficiently quiet MC gain stage. Most MM stages are quite simple and can be powered from a wall wart like the Creeks, NAD, Parasound etc. To get really low noise unit to work with a signal below .3mv is much harder to do correctly. It takes alot more regulation and a real power supply. I use a Naim stageline for MC it costs only $350.00 but the Flat-cap power supply needed to power it will set you back $1600.00
The end product works superbly with low output moving coils down to .1mv
Best,
JC

Immediate solution: Change cartridge to high output.

Long term: Look for another phono preamp,go higher the hierarchy.