Cartridge Loading.....Part II

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, 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!

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.

 

 

 

 

 

Been following the cartridge loading threads with interest. I have a VPI Prime, AudioTechnica ART9 MC and Supratek Chenin which has a cart loading slider switch where I can change values while playing LP's - 47k, 1K, 100 and 10 setpoints.  Used 'As falls Wichita so falls Wichita falls' excellent ECM recording.

At 47K the center soundstage more defined, and background sounds more volume and integrated into the soundstage fabric. 

My take-a-way is the cartridge, the pre-amp and your tastes in sound all partners in the setting that's best. For me 47K.

I run my MC cartridges into my Herron VTPH-2A with no loading according to Keith's reccomendations.  My Lyra Delos and my other cartridges sound better all around compared with any loading including 47k.

@atmasphere  I have been pondering a experience I had recently where a SUT was brought along to a demonstration that was said to be the ideal match for the Cartridge used in the system.

Prior to the SUT being used other models were used and a Phasemation Degauss Device was used, to prepare a condition that was consistent.

When the ideal match SUT was entered into the system, I was immediately astonished at how I was perceiving the presentation as being effortless and free from constraint, in comparison to the other SUT Models.

There was an Alchemy beyond my understanding.

The description on offer from yourself, might just have made me a little more aware of what I was experiencing.

I have made the post available to my Local HiFi Group to ponder over, I'm sure there are few who will enjoy your descriptions and take from it a lesson learned. 👌     

@600ohms 

Care to elaborate?

Thanks

30dB is actually 29.54x higher than the signal.

@atmasphere 

Thanks for the detailed explanation.  It's going to take me a while to digest all that information!    

I don't know what implications there would be with a SUT.  

I suppose this is all variable, depending on the capabilities of the phono stage, as Ralph @atmasphere seemingly explained in the previous thread.  

Normally you have a rather prodigious electrical peak (resonance) with a LOMC cartridge. It might be as high as 5MHz or as low as 100KHz. Generally speaking if a lower frequency the peak will be less prodigious; this depends on the Q (Quality) of the coil in the cartridge. Lower output cartridges tend to have a higher Q since the windings are shorter and wider with respect to their length; this done to keep their mass down.

That peak can be a good 30dB (1000x) higher than the signal! So if you have a 0.5mV output, perhaps half a volt at 2-5MHz is presented to the input of the preamp. Some preamps don't like that (and might sound bright or weird as a result)! For example, if the phono section employs high quality opamps, its quite possible that the circuit will have some bandwidth that that frequency and so could be overloaded (if overloaded, you'll get ticks and pops) or otherwise affected by an RF signal that powerful at its input!

That's why the loading resistor can be so important (its used to detune that peak, thus eliminating the RFI it generates)! Its certainly not to change the bandwidth or frequency response of the cartridge; at least with all the LOMC cartridges I've tested, all showed no ringing at audio frequencies- quite simply their inductance is too low for that, which implies that the load isn't needed to roll them off to prevent brightness- therefore something else is causing the brightness.

When you use an SUT, it simply lacks the kind of bandwidth to pass RFI at 200KHz or 3MHz- whatever the cartridge might be generating. The only thing with SUTs is that since they have a fairly high inductance, they need to be loaded to prevent ringing ('ringing' is distortion, caused by overshoot of the signal and causes brightness and harshness). If you have an SUT designed for your cartridge, the 47K might be a proper load so no worries. 'After market' SUTs like those made by Jensen Transformers are a different matter. They require specific loading that varies according to the source impedance of the cartridge (since a transformer transforms impedance, the correct load at the output will vary depending on the source impedance). They publish the values needed for a particular cartridge in a pdf file available off of their website. IMO Jensen Transformers make some of the best SUTs available.

I suspect that since the RFI issue is conveniently eliminated when using an SUT that this is why some people say that cartridges sound better when played thru them. Personally I don't find this to be the case, but the preamp I use has no issues if RFI is present at its input and can't be overloaded by that RFI, even if its at 0.5 Volts.

So where this is going: If you have no SUT and 47K sounds bright, you need a loading resistor to eliminate the RFI at the input of the phono section. IOW the brightness isn't the cartridge being bright.

If you have an SUT you do need to investigate the issue of its loading, which might be satisfied by the stock 47K input load of your phono section. BTW, if the SUT is designed for that and you try to drive a 100 Ohm load, you'll find it quite rolled off! There is something called 'critical damping' that applies to things like SUTs (and other interstage or line level audio transformers). If you are loading above critical damping there will be ringing causing the transformer to be bright; if you load with a resistive value too low the transformer will be rolled off.

All phono cartridges are generators, having a coil that interacts with a magnetic field. If you have a regular generator making AC power, for example a portable Honda generator for backup use or camping, you'll notice that when you load it more the engine has to work harder to keep the generator (or alternator) spinning. This is because electrical energy has to come from somewhere ('free energy' is still the stuff of conspiracy theories) so the generator presents a harder load to the engine when its asked to make more current.

The same thing happens in a phono cartridge- the lower the resistive load it drives, the harder it becomes to move the stylus since that is where the mechanical energy is input to be converted to electrical energy. IOW the cantilever becomes stiffer. If you have a means of testing the mechanical resonance of your arm/cartridge combination, you can see that this affects the mechanical resonance since in essence you are reducing the compliance of the cartridge.

I am running a 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. My Phono Stage is a Herron VTPH-2A and has load resistors that plug in the back so experimenting is easy as long as I have the proper loaded RCA's to experiment with. I also have the ability to custom make different load resistors if I am so inclined. 

Chuck 

Just to share: 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. BTW, love this cart, much more fitted to my "head banger" style of music than the Kleos. Term often referred to here by some and always by my wife at home 🙂 That's why I built the house of stereo. Now you know.

Kleos for acoustic and classical, Starling for everything else in my setup.

Ultimately it depends on your ears. There really isn’t a “right or wrong”. Personally, 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. That’s my preference. Have fun with it. One day you might like X loading, the next Y… makes it fun.

I'm not an experienced pro, nor a technical engineer:  the instructions on my MC just recommend about 10x cartridge impedance, and, as @rauliruegas 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.  

I don't know what implications there would be with a SUT.  

I suppose this is all variable, depending on the capabilities of the phono stage, as Ralph @atmasphere seemingly explained in the previous thread.  

Best wishes to everyone, and I hope everyone is enjoying their music.  

Dear @quincy  : " My take from this recent thread is as follows.  Load at 100 Ohms or at 47K Ohms with a quality MC cartridge. "

 

No, it's not that way. Your phono stage has several load choices from 200 ohms to 47k and what you have to do with both cartridges as the Delos is to test the quality performance in your system starting at 200 ohms and then change to the other choices till you decide which load is the one that fulfill what you like the more.

 

This is the Lyra J.Carr cartridge designer Delos load advice:

 

" Recommended load directly into MC phono input: 97.6ohm ~ 806ohm. )

 

Btw, " all those years listening to the incorrect load setting.. "  :

no, was not incorrect according with Lyra 500 ohms is inside a " correct " load impedance range Lyra advise.

 

Regards and enjoy the MUSIC NOT DISTORTIONS,

R.

 

Now that I have better designed phono preamps, most of my MC cartridges sound better at 47K loading. There are a couple, especially my Denon 103R that sound better with lower loading, but I like the 103R at 1.6K rather than 100 or 400 ohms.

Since changing loading can't hurt the cartridge or the rest of my system, 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.

Bottom line, I trust my ears.

As Ralph ( @atmasphere )has pointed out many times loading is for the cartridge preamp system as a whole, more for the preamp than the cart. So every combo has its sweet spot.

A moving coil is generally loaded 10 times it’s impedance. The Hana EL for instance has an impedance of 30 ohms, so 300 would be a good place to start. Hana recommends loading the EL @ 400 ohms or greater. I own it and i run it with a Jensen SUT which incidentally has an impedance of which the cartridge sees of 430 ohms. This particular cartridge sounds wonderful any where between 400 a 475 ohms. Lower (numerically) impedance loading will result in an accentuated bass response and the cartridge will sound closed in. Higher loading will result in a brighter sound but also more open. My Rothwell mcx SUT will provide a fixed load of 100 ohms, ideal for many a moving coil, such as my Goldring Eroica LX, which the manufacturer recommends it be loaded at 100 ohms.

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.