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

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.

@maam522a 

For one an MM cartridge has 100s of windings around four iron or ferrite cores, I’m not sure which and a magnet attached to the end of the cantilever that moves inside the field of the cores and windings. These are highly inductive and act like an antenna that is very sensitive to EFI from sources like your turntable’s motor subsequently increasing the noise level.

Your MC has a few windings of copper wire wound on a cross shaped former made of iron at the end of the cantilever that is usually attached to a rubber mount in front of a fixed magnet and in spite of it’s lower output is much less sensitive to nearby electrical noise producers.

The final word though is that your Ortofon uses a nude fine-line diamond stylus which as a rule tracks quieter than any other stylus family not using that kind of geometry. I also think they sound better across the audible audio spectrum than anything else.

@richardbrand 

i took a break from vinyl for over a year to focus on my digital front end. My analog setup when I sold it was MoFi UltraDeck table, Hana ML cartridge and Sutherland 20/20 Mk2 LPS phono stage. 
I just got back into it and acquired a used Clearaudio Concept table and bought a new Hana ML again since I liked it a lot the first time with a new Whest Two.2 phono stage.

Going based on memory, this configuration sounds quieter and more like CD than my previous setup that had a more traditional vinyl analog sound. Completely different. I suspect Clearaudio is less noisy than the MoFi and Whest is a more modern sounding phono than the Sutherland. Not better not worse - just different. No it’s not a match sonically with my considerably more expensive digital source (upconverts everything to DSD1024) and it wasn’t the objective to begin with. But I’m impressed with the sound quality. Walking into the room I could never tell it’s vinyl that is playing. That’s how clean it is.