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

The lower value 200 ohm vs. 47k ohms means more loading which tends to attenuate higher frequencies (because we hear things in terms of overall balance, attenuating highs can also  be perceived as more bass).  Another way to attenuate highs is to lower the VTA/SRA (lower the pivot point of the tonearm).  This means that, to some extent you can play around with both loading changes and small VTA/SRA changes to find the best combination for achieving the tonal balance that you want.  I know this adds to the complications, but, it also may enhance your sweet spot.  

@larryi to add what he said, it is one of the best things about vinyl. On one hand you want some setup to be dead on, cart alignment etc. But, when it comes to final sound there are lots of possibilities between loading, VTA, and VTF (to a degree). All can be tweaked to achieve just about any realm of balance desired. 

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

 

This is a common trick for many listeners over 60.  Brings back the "airiness" of youth.  Do whatever sounds best for you, not others.

The lower value 200 ohm vs. 47k ohms means more loading which tends to attenuate higher frequencies.

If this were the case it would be easily measured yet I have yet to see this actually documented.  

Another way to attenuate highs is to lower the VTA/SRA

This is another case of something widely accepted, easily measured yet completely undocumented.

I want to be clear that I am not doubting there is a change in sound from varying load or changing SRA, I am just suspect about the "change in frequency response" explanation that is widely accepted as the cause. 

Peter Moncrief in IAR 5 makes a compelling case with measured confirmation that loading of an MC cartridge does not materially effect the measured frequency response of a MC cartridge.  He then goes on to show how loading does measurably change the amount of IMD created from the trackability tones on the Shure TTR103.  He then finally proposes that the excess IMD caused by a lightly loaded MC cart is often perceived as high frequency detail that many have grown accustomed to and the "dark" sound of heavily loaded cartridge can be due to a system being tuned for the typical lightly loaded case.

dave