NOT A CLUE what you are talking about.

SPDIF are digital inputs and outputs, the turntable has analog outputs. They are both RCA plugs and jacks but that is the only similarity, Am I missing something here?

You need a pre amplifier with line outputs that you can feed into a analog to digital converter (possibly the firewire device) then you can take that signal and record it digitally.

LOL....your RECORD PLAYER has what is called and RCA output jack. An analog signal is transmitted through this for hooking it up to things like stereos or DJ mixers.

Your Firewire device has an SPDIF jack which is also an RCA type of connector BUT it transmits/receives digital data...not analog. So you can't just plug your turntable's output into the SPDIF jack.

What you should do is connect your record player to either a mixer of some sort or an amp. I think that there are amps made specifically for record players that would be used for a stereo system, but I don't know what they are or where you would find one.

You can't directly connet the turntable to your interface the output it creates would be to low. You need either mm or mc phono per amp depending on the type of cartridge you have in your player. You most likely have a mm cartridge in your record player now (most cheap ones do). You can get decent cheap mm phono preamps here here http://www.phonopreamps.com/. I have used them with no problems. No longer use them though because I have upgraded to mc cartridges.