Cartridge Loading

Dougdeacon, so you consider the loading of an MC cartridge to be an "equalizer" or "tone control" to compensate for deficiencies in the system/room? What would be the correct loading assuming that your system is perfectly neutral and located in an acoustically perfect room?

There are those who believe that there is only one correct load and that is the one which achieves "critical dampening." From my own experience, the correct load is very much system dependent. Phono stages, in particular, seem to be quite dramatically different in the way they interact with particular cartridges. I agree with Doug that the only way to tell is to try different loading.

At a minimum, try something near 200 ohms, and almost unloaded (47 kilo ohms). Most of the big changes in sound will be down near the 200 ohm range. For example, the difference between 200 ohm and 300 ohms will probably be bigger than the difference between 1 kilo ohm and 47 kilo ohms). Keep that in mind if you are trying to minimize the number of trials.

As a pure guess, a manufacturer's recommendation for a loading of 200 ohm and higher means that the manufacturer thinks the cartridge works pretty well with very little loading. I would not be surprised if 47k works well in setups where there is no tendency toward excessive brightness or upper frequency distortion.

what is the suggested range from Benz?
You may want to start with 1k since that is the stock load from a Benz phono amp.
However, everyone above is right. MC cartridges can "potentially" sound the best, but only if the right work is done.They are not plug and play.This is one of the reasons that MC builders also make their own step-up or phono section. So if you bought a Benz Lukushek you would probably be alright, but not necessarily optimized.
Loading is all part of what I call "the charm of analog".
With a good analog rig, there is so much to do;VTA,VTF,azimuth,loading,are all part of the fun.And all worth the trouble.
Indeed, some of us, see this as a opportunity to experiment and strive for more knowledge and better sound.

If you want plug and play,get a CD player.
but you will lose the charm,,and the sound.

have fun it's a hobby

e

First, I also agree with Doug, Larry & others that a correct load is very much system dependent in which listening room is also a main factor. Though in theory for a cart with 25-ohm "actual" internal impedance(sometimes 25 ohms is just a nominal value +/- a few %), 200 to 300 ohms resistor loading seems a reasonable point to start with. With 0.8mV output, an SUT(with 25-35 ohms transformer loading?)/head amp may not be as neccessary as LOMC.

Second, if another Benz Ace M user says he found 300 ohms is the best, you have to see his system whether it is similar or totally different from yours. There would be a large sonic deviation between the one uses 1000w solid state mono blocks for his giant multi-ways floor standing and the other uses 8-15w tube amp for a Fortex 8" full-range speakers.

Third, different cart manufacturers seem to have different approaches for their productions. So it is always better to have several impedance resistor loadings, in your case, say, 200, 400, 600, 800, 1000, 47k ohms, etc.

Dan

If plug-n-play better suits your style, I'd suggest sticking to MM's. You'll save both money and time. LOMC's not only cost more, they take more work if you care about sound (and I assume you do, else you wouldn't have asked).

I hate to disagree (once again) with Doug:)...but he must have seen J Carr's reponse to the question of loading for MC cartridges 9copied below)

You are very crisp with your technical specifications, however, you openly offer a wide range for catrige loading (100 Ohms to 47 kOhms). Why such a range?

First, because the loading of a low-impedance MC is not really an issue for the cartridge itself. An MC cartridge is a mechanically-driven electrical generator, and a not-very-efficient one at that. Unlike loudspeaker drivers, the meager efficiency of a low-impedance MC cartridge implies that loading applied in the electrical domain will have relatively little effect in the mechanical domain (which is where you will see effects on aspects like tracking performance and distortion). Also, due to the very low inductance of the signal coils, electrical loading will have practically no effect on any signals in the audible range, and this has other benefits in keeping a relatively flat phase response in the audible domain (a general rule of thumb for good phase response out to 20kHz is that the electrical frequency range should extend to at least 200kHz). This is a completely different situation with high-inductance MMs and MIs, where changing the loading will affect the frequency response in the audible range, and the phase response even more so.

So, if electrical loading doesn't change the behavior of the phono cartridge in the audible frequency range by much, why does the sound change so dramatically? The answer is that the inductance of the cartridge coils will resonate with the capacitance of the tonearm cable (and distributed capacitance of the coil windings) and create a high-frequency spike. The magnitude of this spike can be extremely high, and may give many phono stages outright problems if it isn't damped with loading measures at the phono stage input. I don't have my lab notes at hand, but from memory loading a Delos with 47kohm can result in a 28dB spike at 6~7MHz. Some phono stages will have been designed so that they remain unflustered by this, but many phono stages will not be happy with such brutal treatment, and will not sound good because of this.

This pretty much matches my own experiences and is confirmed by the design of the Halcro DM10 Preamp which has a fixed MC loading of 220 Ohms but an infinitely variable resistance between 10K and 60K ohms for MM/MI and an infinitely variable capacitance between 70uF and 430uF also for MM/MI.
This may also have something to do with the philosophy of simplifying the electrical path for the extremely low output signals of LOMC and MCs in general.
Having played extensively with the adjustments of Resistance and Capacitance for my Garrott P77 MM cartridge and hearing the enormous differences, I can assure you that it is not a "plug-n-play" alternative to MCs and may in fact be the reverse?

I would love to hear Raul's opinion on this one?

Sorry Doug :)