Yamaha as-3000 with Denon dL-103R low output MC cartridges

On my system, I use a ZU Audio modified DL103 and load it at 400 ohms. 

Thanks all of you. Very useful information.
@stereo5 what amp do you use? Integrated or pre/power amp? Thanks

I use a McIntosh C2500 preamp. The MC section has 6 impedance settings that I can change on the fly via the remote.  I also use it with a McIntosh MC302 300wpc amp. 

@dekay you advised Yamaha's MC section is set @ a "fixed" 50 ohms (100 ohms is the recommended load for the Denon). 
im sorry I’m totally noob here so what issue will happens at fixed 50 ohms against sl-103r?
In other words, you means dL-103r on as-3000 integrated is a no no?
Or you means 50 ohms is still can play with dl-103r, but 50 ohms cannot push dL-103r to its fully potential?
thanks on advanced.

Vuth...:

No, it may sound fine with the 50 ohm fixed load, but then you will not be able to experiment with other loads (you did mention "full potential").

Considering how positively the phono section of your amp is reviewed, and that it has enough gain, I would give it a go (and I'm not a gambler).

Perhaps it's possible to increase the load via cable choice and/or another method if you wish to experiment?

Anyone want to chime in on this?

DeKay