Cartridge Loading.....Part II


I read last night the below noted discussion with great interest.  It's a long post but worth the effort and I found it interesting.

It started me thinking about the amount of loading on my moving coil cartridges.  Years ago I purchased my first MC Cart, a very nice Benz Micro Glider, medium output of 0.5 mV as I recall.  At that time I inquired about loading here on Audiogon.  I was convinced, via discussion, by another member, that 300 Ohms was the magic number, so I thought.

Time moved onward and my second MC Cart is currently a Lyra Delos, again medium output 0.6mV.  Both carts had Boron cantilevers', 6 nines oxygen free copper coils and line contact diamond stylis.  When I set up the Delos I did not change or even consider 'loading' changes.  That was a grand mistake.....

Well, thanks to this specific thread I started to second guess myself . (you can do this when retired and more time is on your hands....)

My take from this recent thread is as follows.  Load at 100 Ohms or at 47K Ohms with a quality MC cartridge.  I opened up my Conrad Johnson EF1 Phono Stage this afternoon.  Found it set at 500 Ohms loading.  100 Ohms is not an available setting.  Damn...All these years I've been running the wrong loading, and on two carts, back to back...  I don't recall why I set the loading at 500 Ohms.  Faulty logic.

I reset the loading to 47K, buttoned things up and called the wife in for a listening session.  Sure as heck both of us noticed the highs were crisper and more 'apparent' than in the recent past.  Not a huge difference, but yes, a difference..  Hard lesson learned!

So, you smarter folks on this site might banter amongst yourselves, but in reality there are those of us, behind the curtains, reading and listening!  I just wish I hadn't wasted all those years listening to the incorrect load setting!

Ending with a sincere thank you very much!!

Lou

 

quincy

@intactaudio , I think miss-tracking distortion and IM distortion are two separate but additive issues. 

There is a big difference between normal cartridge loading and an impedance approaching zero. This is all conjecture (theory?) at best. I have not seen a study done on tracking ability vs cartridge loading. I have seen distortion measurements on the same cartridge run voltage mode vs current mode and distortion is certainly lower in current mode. I think this is me agreeing with @rauliruegas again. It is indeed a strange world. 

@rauliruegas , I will run the Seta in both modes with and without digital RIAA correction to see if I can tell a difference but it will be a while. Rob has told me my phono stage is 4 to 5 weeks away. I still have not cornered a cartridge yet. All the cartridges I am interested in are "special order" and it seems nobody is making anything at the moment.  

Mijo,

I agree that there is a big difference between loading @ 47kΩ and loading approaching zero.  These two extremes very closely represent the "ideals" of current vs. voltage amplification.  It may very well be conjecture but discussion of this on the most basic level is the only way to get a common solid foundation for everyone to build upon.

 I have seen distortion measurements on the same cartridge run voltage mode vs current mode and distortion is certainly lower in current mode.

Interesting.  Now the question becomes what was the cause of the distortion change?  I see two possible options:

  1:  The distortion of the two modes of operation were different.

  2: The effect of the radically different loads altered the behavior of the cartridge resulting in different measured distortions.  

Chances are the difference is some combination of the above two and simply removing the cartridge from the tests and using a sound generator should illuminate the differences between the two modes of operation. Repeating the measurements with a number of different cartridges should also illuminate if there is a specific pattern happening.  

 

dave

Dear @intactaudio  " the possibility that heavy loading may actually reduce mistracking hasn't been mentioned or covered by anyone .."

 

I did it.Over the years participated in no less that 8 threads about cartridge loading here and wbf and in one of them I posted something as:

 

stifness of cantilever it's a good thing because cartridge designers normally looks for the stiffer cantilever material as Boron, higher stifness the better in favor of better quality level listening performance.

Anyway, all is done.

 

R.

Ok guys, I'm getting dizzy.

@rauliruegas , I already have that test record!

Channel D has received my wire transfer ($500 credit) and A friend says the Platinum Signatures will arrive any day. I might also get an Ortofon Verisimo., teeter tottering on that one. Since I can run the phono stage 4 different ways and I can record records to the computer I will be able to make 192/24 files of all the results which I can download so everyone can judge for themselves as long as your system can play files. If not then GET WITH IT. Digital is hear to stay (spelling intended). It allows you to do cool things you can not do otherwise and share the results with friends. 

@rauliruegas  I have no idea what is better but I will figure it out and I will be happy to email you the files so you can compare. Then you can tell me!