Which receiver for better sound with vinyl?

I have an old stereo system from the '70's: Nikko NR-515 stereo tuner/amp, Marantz TT 1060 turntable. I also just put together a new home theatre setup: big Samsung plasma TV, Denon 1910 avr receiver, and Jamo 606 5.1 speaker system with Jamo 250 sub. I'm trying to figure out if I'll get better sound for music (vinyl) with a phono preamp and hooking up my tt to my new denon receiver, or keeping the two systems separate. If I keep them separate and continue using my old stereo receiver with the tt, could I hook it up to my new Jamo speakers, since they have two sets of speaker clips on each speaker to permit bi-amping? Would my Jamo speakers likely sound good with vinyl? Obviously, I would only use one input at a time!
None. You don't mention the cartridge but generally a freestanding phone amp is always the way to go. Then use the receiver. I would also check out a different speaker then the Jamo's, which may sound good for home theater, but not for two channel stereo.
I'd keep it the way it is,those old Nikko receivers were a lot better than most people belive.I had several.
Schubert, do you think it could drive my Jamo speakers? Will I damage anything if I try it?
NO you cannot have two amps/receivers connected to the same speakers at the same time. Even if one is turned off. Serious damage can/will occur to the amp/receiver that is turned off., and possible damage to both if you were unlucky.
The power from the amp or receiver that is turned on goes back into the one turned off and those transistors in the second amp/receiver are NOT designed to handle that sort of current backing ito them!
You could use a switch box that is designed to allow ONLY one OR the other but not both to connect at one time.
You can use the phono stage in your Nikko, connected to the Denon. With the turntable plugged in to the Nikko, and the Nikko's selector switch set to "Phono", connect from the Nikko's "Tape Record" or "Tape Out" RCA jacks to an unused input on the Denon. This bypasses the volume control of the Nikko. If you aren't sure that you like the resulting sound quality, disconnect the speakers from the Denon and connect them to the Nikko. If you still aren't happy with the sound, then perhaps a stand-alone phono pre is a good idea.
Thanks, Elizabeth and Goofytwoshoes. You've both saved me time and money since I was about to either try connecting both receivers and/or ordering a preamp.

I just tried running the Nikko to the Denon and it worked like a charm. The sound is still kind of muddy, but I'm going to start by buying a new cartridge and stylus, and see how that goes first. The one I have is ancient, probably not replaced since the early or mid-80's. Thanks for the help.
the Nikko stuff from the late 70's had a pretty good phono stage, so its probably the cartridge that needs work. Hook it up to the Denon aux input and it should be fine. Dont run it into the Denon's phono input.
Have you ever cleaned your stylus or checked it under magnification? Unless you had a regular routine of effectively cleaning it, the stylus is probably caked with gunk and fuzz. When I got back into vinyl 4 yrs ago, my new cartridge went from sounding good to muffled in just a month or two. Viewing the stylus under a magnifier, all I saw was a big, black amorphous, fuzz-laced blob. Several applications of a dry Mr. Clean Magic Eraser (stroked from back to front, brushing off the abrasive flakes each time) finally cleared off the gunk and enabled me to see the bare stylus again. The sound of course improved markedly.
Got the new cartridge, and it sounds great! Of course, my brand new six week old Denon receiver is now dead (at least it's under warranty) so I just hooked up the Nikko directly to my Jamo speakers. It sounds fabulous. When I get the Denon back I'll listen to it to see if I like the sound as well. If not, I think I'll get an A/B switch so that I can share the speakers between the Denon for TV/BD where I need digital and the Nikko for vinyl.