Azur 640p /w Denon DL103 and Clearaudio Virtuoso?

The output and load impedance on the Denon 103 are not, in fact, 100 ohms. The internal impedance of the cartridge is 40 ohms plus or minus 20%. The recommended minimum load impedance when using an active phono stage is 100 ohms. Try cutting the horsepower in your car's engine by 40% and inflating your tires to their minimum PSI. You can still get to 7-11 for that Slurpee, but it might not be the funnest ride.

Good point. Well I think my preamp will have plenty of gain. When listening now, I never turn it up past 9 o clock...and that is at a blasting level. So I think I should be fine in that area.

.3 mV is only 60% of the .5 mV minimum. That can be significant.

You might have to turn the volume up further than normal at best to get to normal listening volumes, or the volume might not ever get as loud as you like. If you have to turn the volume up close to max, you might get more noticeable background noise levels also.

If you do not listen at higher volumes, there is a better chance of it working OK. Try it and see. If it doesn't, then just be prepared to add a good step up device. This will probably cost at least a few hundred as well for a decent one so as to not degrade the sound, so be aware.

Interesting. So a difference of 0.2 mV will make that big of a difference in the MC stage? The output and load impedance on the DL103 are both 100 ohms, which matches directly with the 640p specs.

According to the 640p manual:

"If your turntable uses a moving coil cartridge, connect outputs here
(0.5-1mV, with 100 ohm 220pF loading)."

So it does look like it requires an output of 0.5, but would it really sound bad with the an output of 0.3 mV from the DL103?

To answer your question, yes both will be safe, in the sense that nothing will break. You may find that both the gain and loading in the MC section will not be optimal for the 103, resulting in too much noise, not enough dynamics and a skewed frequency response. As Mapman says, the Virtuoso should be a good match from an electrical standpoint.

You'll probably need a step-up device for proper gain with the low output MC DL103.

I think the Virtuoso MM will be OK.