New Cartridge or New Preamp

Hi All,

I have upgradeitis. 

Here's my system:

Rogue Rp1 Preamplifier

Rogue M-120 Magnum Monoblocks

VPI Prime Scout w Ortofon Black (and Bronze)

Ohm Walsh 5 LE

So here's the thing, I just replaced the tubes in my preamp, same tubes, gold lion with gold lion, and the improvement was astounding. Everything sparkles. Happy listener.

So now I want even more and the next logical thing is that the lifespan of my cartridge is nearing the end so I need to start thinking about replacing.

My top choice is the soundsmith zephyr. I've heard it on my table, have really enjoyed it and know it would make me very happy. BUT the RP1 pre-amp is nearly the same price as the cartridge, What's the rule of thumb there, if any?

My belief is a nicer cartridge with a very well made pre-amp will still make a noticeable difference and price doesn't matter, your ears do...but I'm interested in hearing other's opinions.

Another thought would be getting a new external phono pre-amp. I do have a musical surroundings phonomena ii+ but I didn't find it to be all that much better than the onboard phono of the rogue. But open to ideas.

I'm looking for more detail in my playback at this point. I'm very satisfied with the openness and power I get from the tube monos and ohms currently.

Thanks in advance!