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

Showing 3 responses by larryi

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.  

I suppose I should have preceded my comments with the phrase "I perceive as" because I did not take measurements.  In any case, the sound changes, both with loading changes and VTA, and whether or not it is actually added distortion that one might be favoring with a higher VTA and lower loading (higher resistance in parallel), I don't really care; I like what I like.  I suspect that a lot of the appeal of vinyl playback IS something added, and perhaps something lost, as compared to the original recorded signal, but, I don't have any sort of religious commitment to authenticity/accuracy.  I happen to like, for example, many works of visual arts that don't depict their subjects with the same "accuracy" as high definition photography.  

If light loading is entirely added intermodulated distortion and the "real" and "accurate" sound is what you get with high loading, I will take distortion.  As an experiment, one could try the loading of a MC with relatively high source impedance (like a Denon 103) with something like a 10 ohm resistor.  One would have to compensate for the loss of gain from using such a resistor, but, one will hear quite a difference in sound as compared to a light loading (e.g. 47k); I would not chide anyone for preferring lightly loaded and accuse them of having incorrectly becoming "accustomed " to light loading.  

What it boils down to is that loading matters to the sound, but there is some disagreement here as to why it matters and the cause of the sonic difference.  One position is that low loading is preferred because it CAUSES distortion that is perceived as high frequency information and people have grown accustomed to, and prefer, the distortion.  Another point made here is that RFI overloads some electronics causing distortion which is ameliorated by loading that damps RFI.  I suppose these are not contradictory statements and they may both account for some preferring low loading and others preferring more loading.  Jonathan Carr (Lyra cartridge designer/builder) says that low lading is preferable, because it preserves the high frequency response, which is one of the things people pay big bucks to get from MC cartridges, but, that higher loading might be necessary to kill RFI that can overload some gear (Atmasphere's position, and I tend to agree). 

As to Atmasphere's response to my statements about the sonic effects of loading-- that loading has no effect on the cartridge, except to make the cantilever harder to move-- I was merely stating that the effects of loading changes can be heard, not that loading physically affects the cartridge.  There are cartridge experts that say that the back EMF changes from loading are so negligible that the effect on movement of the cantilever is mostly theoretical an not a practical reality.  

Perhaps my statement about having to compensate for difference in loudness where a low value resistor is used (high loading) was misconstrued.  I was merely pointing out that when making a comparison, to be fair, one might have to increase the volume a bit for the high load scenario to compensate for the voltage drop across the load resistor; with a high value resistor (low load), that drop is less significant