DENON DL-304. Is it the bargain sound or not?

Yes, I agree. I think loading is the problem. The MC input impedance on your preamp is 220 ohms. I guess somewhere between 40 and 100 ohms would do it for you if you don't have a transformer. You could make up some loading plugs and try different values. 49 ohms would net you 40. 183 ohms would get 100. Loading plugs are hooked up as a parallel load, usually with a Y adapter. You can figure out the values here:
www.sengpielaudio.com/calculator-paralresist.htm

The 304 is a good cartridge, just a little tricky to get dialed in. Once you figure out the load you can solder the parallel resistors right to the input jacks inside your preamp.
Regards

Amandarae and Fleib,

You have my curiosity up--just how good *is* the DL304? I've contemplated that cartridge myself.

Hi Fleib!!!
I think that it is the most interesting solution i "ve ever heard until today!!

Could you be more specific in order to arrange the test?

DB electronics still make their kit which containes a selection of resistors and 2 Y connectors. Good for those who don't like to solder.

Hi everyone again!
I have done just what Fleib says. I have construct 8 pairs of RCA connectors, with resistances as parallel load with Y adapters for the two channels of my preamp.
The results dissapointed me.
The most "closer" sound for my taste was with 76 Ohms & 93 Ohms plugs.
Comparing with the previous situation (directly connected to my preamp) there was a better balance in high frequencies and a litle bit more bass. The middles become worse and nothing was comparable with my other turntable combination (Lenco L-75 with Denon DL-160).
I suppose that Technics SL-1200 MK2 with Denon DL-304 combination, was not make any better results from the other turntable, on the contrary... it was MUCH worse!
So.. after my last attempt to change the sound, the conclusion is that i must change the Denon DL-304, because i don't have any possibility for better matching, with my Onkyo's P-304 preamplifier MC phono stage...