MM to MC - Stunned - Please explain the noise difference...

Sounds like you made a great upgrade. Congrats. The MC X30 has a good fan base here. 

I have both MC and MM cartridges using similar tonearms and  a higher end phono stage. In my experience I have never noticed reduced background noise with the MC cartridges. Stylus profiles are similar to the MC X30 and even the Shibatas that I have are not noticeably quieter in the grove. I do prefer the MC cartridges over the MM but mainly due to bass response and detail. 

elliottbnewcombjr

"I suspect something was previously wrong to produce so much noise."

I tend to agree with this. Tonearm/cartridge match and alignment can make significant differences/improvements.  I would expect the new Ortofon MC to eclipse lesser  Ortofon MMs or the V15 v (especially with a well worn stylus or generic replacement).

@vintageadict 

Maybe some serendipitous change along the way. 

Listening to Natty Dread at the moment and Bob says - Yah Man.....  Just relax and enjoy man. No need to explain man.  Smoke some ganja and enjoy - it's good cause God bring it up from the ground!

One more thought. 

The V15 v is a higher compliance cartridge (25) vs 15 μm/mN of the Ortofon. If your tonearm is more of a mid mass or on the heavier side you may have had a miss-match. I ran a V-15 iv on a Thorens TD 160 years ago and thought it sounded pretty rough on worn vinyl. That turntable has a heavy tonearm (17-18 gram effective mass I believe) and I switched the cartridge to one with a lower dynamic compliance. It improved things quite a bit. 

I moved the V-15 iv to a 7.5 gram tonearm and it sounded much better. I still have the cartridge with jico sas stylus and enjoy it. I would hang on the V15 if you think this could be case and you have a lower mass tonearm. 

If your ortofon was an OM or 2m series they are higher compliance as well. 

This is a good tool.

https://www.vinylengine.com/cartridge_resonance_evaluator.php

@elliottbnewcombjr Update: the prior MM cart was a Ortofon 2M Black with a nude shibata stylus, aluminum cantilever. Best MM I experienced at the time.

The MC I replaced it with is a HANA SL (now discontinued) also with a shibata stylus and aluminum cantilever.  Not sure if that makes a difference in your insights. 

However, even though they are both shibatas, I found the HANA to just be more detailed and forgiving than the 2M Black.  Both were about the same price range.

@audphile1 

progress from what?

Seems to me to be a milestone admission from a vinyl fan, that your upgrade to an MC cartridge made your record sound like a CD!

I started down the vinyl path again to try to find out for myself if vinyl really is better than digital.  Quickly discovered that all the HiFi stores that dumped on digital now happily demonstrate using streamed digital.  Also discovered that almost every record mastered over the last 20 years has been through a digital stage.

Personally, I have my vinyl playback to the point where I am agnostic about the source, vinyl or CD, but there is a significant step up required to approach SACD.