Cartridge Loading.....Part II

Dear friends: LOMC cartridges are not sensitive to load impedance but exist a relationship between the cartridge internal inductance and the overall capacitance with the phono stgae/IC cable that are the ones that could change the " color " of what we listen with changes in load impedances.

Why active high gain phono stages does not comes with fixed 47k impedance? because is not the standard for a LOMC but more for MM/MI cartridges. Normally active high gain phono stages are designed and comes with choices with load impedance between 50 ohms and 1k impedance values. Yoday phono stages designs comes with high/healthy overload(headroom levels and really has not problems .

So, we have not to distress about LOMC load impedance just tests the alternatives that has your phono stages and set up the one that fulfill your needs. There is no correct or incorrect choice about and no you can't have compliance changes with load impedance changes that could be higher enough for you can detect or for you have to be worried about, no distress other way of thinking is just bs.

Next, the first hand experiences of almost all of you audiophiles about:

 

"""  Benz Micro Wood SL and have it loaded at 150 Ohms which I thought sounded best after some trial and error. The specs for the cartridge list >100 Ohms. I tried 47K Ohms and as others have experienced I found that setting to be harsh and the music lacked cohesiveness. """

 

"" I do not subscribe to loading a moving coil at 47k, I reserve that for my many moving magnets.

What is neat about my pro-ject tube box DS2 is that I am able to dial up any impedance loading so desired on the fly from 0 to 1000 ohms.  ""

 

"" specially my Denon 103R that sound better with lower loading, but I like the 103R at 1.6K rather than 100 or 400 ohms.

 I'm happy to experiment with all the different settings, regardless of what's considered correct.

FWIW, I like some of my MM carts at 68K rather than 47K. I wish I had 100K to try easily. "

 

"" 

indicates, the instructions on my Lyra cartridge recommends anything between 100 to 1000 ohms.  

The phono stage (Manley Steelhead) recommends just listening to the cartridge at various loads, and pick what sounds best.  ""

 

"" like others I have found 47k to be way to bright/harsh when tried. I have usually settled into more of a “loaded” sound than “unloaded” as I prefer the generally beefier low end. ""

 

"" my Lyra Kleos sounds best anywhere between 60 to 500 ohms depending on recordings (overly dark ones at 500, overly bright ones at 60 and 400 for most, that's why I love the PS audio stellar phono preamp with its instant ohms adjustment on the remote). However the changes are not very significant. On the other hand, my new Sumiko Starling sounds best between 100 and 280 but changes are much more significant. Anything 300 and higher, count me out since it loses its slam. ""

 

R.

 

 

 

 

 

Well, this has been an interesting thread.

I do appreciate everyones response in regards to loading.

I did a little internet search and here is what I came up with in regards to loading.

I am quoting from Analog Planet, a site of which I've never heard of prior to today.

 

"The Delos, machined from solid aluminum billet, features a 2.5µm x 75µm Namiki microridge line contact stylus, a solid boron cantilever and coils of 6-N high purity copper. Output of the 7.3 gram cartridge is a relatively high 0.6mV@5cm/sec while internal impedance is moderately low at 8.2 ohms. Like other Lyras the Delos uses a yokeless, Neodymium disc direct magnet system. The connection pins are silver plated.

As with any line contact type stylus, correct VTA/SRA is critical to optimizing performance so a VTA adjustable tonearm is recommended if not mandatory. Compliance is approximately 12x10cm/dyne at 100Hz. Recommended tracking force has a narrow window of 1.7g—1.8, with 1.75 “preferred.” Recommended loading is between 91ohms and 47kOhms determined by listening. VTA is 20 degrees, which Lyra says is achieved with the arm parallel to the record surface. As with other Lyras, the generator is integral to the body as opposed to being a completed mechanism inserted into a body. The result is better mechanical grounding, energy transfer and inherently correct alignment of the generator and body.

You can determine the “mathematically correct” loading according to Carr’s instructions by determining the total capacitance between the Delos and the phono stage. While the ultra low inductance of moving coil cartridges makes capacitive loading far less critical than it is with MM cartridges, there remains a relationship between capacitance, load value, bandwidth and the amplitude of the ultrasonic resonance.

Usually though, a setting of 10X the internal impedance is a good starting point, which is why Lyra species 91 ohms as the low, which is just above 10X the Delos’ 8.2 ohm impedance. According to the instructions if your cable’s capacitance is 100pF per meter, for instance, loading at 390 ohms will suppress the peak to 3dB while 200 ohms will suppress it to 0 at the expense of slightly poorer phase response and reduced dynamics. I went with 500 ohms but listened at 100 ohms as well, which is where I preferred it.

One interesting new design wrinkle here is a new body angle and a “pre-angled” damper system that aligns the coils and magnetic circuit with the application of the proper VTF. Most cartridges, Lyra claims, provide this alignment only when no tracking force is applied."

I dug out my manual for my C-J EF1 phono stage.  (btw I run the phono stage into a C-J Premier 17 LS, a very high quality tube preamp I acquired from a good friend 20 years or so ago.)  The avail loading is: 200 ohms, 500, 1.9K, 9.6K, and 47K.  These are set by dip switches. One sentence I will quote from the manual.  "The factory preset 47K load (all switches off) will be best suited to most cartridges."

C-J does not mention MM or MC carts in any of their instructions....go figure.

I am running Audio Quest King Cobra interconnects throughout the entire system chain of equipment.  I have no idea how to calculate the mathematical correct loading; and even if I could, it may not be avail in my phono stage.  Since my Pre amp and Amp are tube C-J equipment, I'm hoping C-J did all the 'correct engineering' so their equipment runs together in harmony.  The way my system is stacked it's a hassle and 1.5 hr job to switch the loading, which requires me to get on a ladder...no fun.  For the time being I'll leave it at 47K.  If I decide I don't like it, I'll switch to 200 ohms and call it a day.  I really don't want to 'play around' with loading.  Just find the best setting and leave it alone...Thanks for all the feedback!

Recommended loading is between 91ohms and 47kOhms determined by listening.

@quincy I love that Lyra states things this way- Jonathon Carr is well aware of how differently phono sections behave when presented with the RFI generated by LOMC cartridges. Normally you'd expect a very specific value for something like that, not something determined by 'listening'. But until more phono preamp designers get the implications of the LOMC cartridge making RFI, about the only way to do will be by 'listening'.

Well, played many favorite records at 47k for awhile.  Didn't like it overall.  A little to bright, if that's a good analogy.  Switched loading to 200 ohms yesterday.  Better.  Not much difference from the original 500 ohms I've been running for the last decade.   Will leave it at 200 and call it good!

Well, played many favorite records at 47k for awhile.  Didn't like it overall.  A little to bright, if that's a good analogy. 

@quincy It is. If you experience brightness, IME this is because the phono section really isn't happy with RFI at its input. So loading is really the best thing you can do.