Ortofon 2M Black Measurements and Optimal Loading

The Ortofon 2M Black is well known as a bright cartridge. Well, hopefully it's known as a bright cartridge because if you read the various "reviews" out there, perhaps only one says that it sound bright. So I decided to make some measurements to confirm. I had some issues getting accurate measurements below 500Hz, so these graphs go from 500Hz to 20kHz. Measuring vinyl setups is still new to me. I am sure that in time, I will get better at it, just like how I did with headphones. I used to Analogue Production Ultimate Analogue Test LP. The phonostage I used was the RSA F117 Nighthawk, which was damn accurate when I measured it with a reverse RIAA filter.

Ortofon 2M Black Frequency Response
Load: 220pF, 47k ohm load
Top: lateral pink noise
Bottom: vertical pink noise


To be continued

 

So I wired up a gimzo (see Ratshack splitter below) to play around with different loads. I effectively put a 220k ohm resistor in parallel with the 47k to create a 38k ohm load. As we can see in the graphs below, result is a little bit better. We could probably go a bit lower to 35k or 30k but this is good enough and I was worried about killing off too much of the top end.


Ortofon 2M Black Frequency Response
Load: 220pF, 38k ohm load
Top: lateral pink noise
Bottom: vertical pink noise

 

Yup, stuff like this certainly takes a lot of audiophoolisticstry out of the equation. Ortofon specifies a optimal load of 47k ohms for this cartridge, but it should really be somewhere in between 33k to 40k ohms. A problem is that few affordable phonostages will offer a wide range of loading options, but there are ways around it with a soldering iron and 2 cent resistor.

 

I'm running about 2.5 ft. of Mogami W2552, which is 10 poofs per foot. That's about 25 poofs for the length. So total capacitance should be about 255 poofs + tonearm wire capacitance.

 

The 2M Black is a bright cart. Subjectively, I wouldn't say sibilant, but "spitty" - very much an emphasis in the mid-treble. I have no idea as I haven't heard the Red.

Yep, I read the Hoffman forums and saw a little bit of that audiophoolisticstry going on from a few peeps. One suggested that trying to flatten the response was pointless given that vinyl gear tends to measure all over the place (I guess the other option is to keep spending thousands of dollars on gear to happen upon the right "synergy" rather than address things directly with a soldering iron and knowledge), another cited the lack of trust with "shareware" and DIY test setups implying that Ortofon's expensive B&K measurement equipment could not possibly lie (where have we heard something like this before?), and another who absolutely had no clue, produced his own measurements showing the 2M Black to almost perfect.

I'm not against things like component matching, "synergy", and personal preferences, but the vinyl world has too much shit that is all over the place. A little bit more knowledge (objectivity) would be a good thing in this arena.

 

Doing the FFT thing with noise resulted in bass rolloff on the measurement whereas a tone sweep showed me everything was flat.

 

Discombobulated results. I didn't set the FFT window high enough, but this should give a clearer picture of what is going on. Just one channel.

47k and 220 pf Loading (not including tonearm wire and interconnect)


At stock 47k load, we can see that there is a little bit of lower and mid treble emphasis, and quite a bit of rolloff in the last half of the top octave.

35k and 220 pf Loading (not including tonearm wire and interconnect)