Ortofon Per Windfeld Load Impedance?

This loading question was a concern until I received an answer from Graham Tricker Tron designer. I have an Allaerts Finish cartridge and Jan recommends exact 845 Ohm load, so I asked Graham to do so with the Tron Seven Tube phonostage. Here his answer: " the Seven you have is set for 117 ohms wich it presents to the cartridge. Don't get hung up on the "loading" issue. It is a much misunderstood subject. Loading is normaly quoted for solid state electronics and can only be set by putting a resister directly across the signal path. This degrades the performance by a huge margin. The Seven is transformer coupled so the loading works completely differently and there is no harmful resistor across the cartridge coils. Jan Allaerts uses a Krell PAM 5 preamp wich is solid state, he has always used SS and there is only one way to load a cartridge with SS phonostages, that is with a resistor.
Loading is basicaly what the designer found worked best in his "test" system, and in his test environment ( listening room ). Loading is NOT calculated or worked out by measurements- it is an arbitrary figure made by listening tests. This changes in individual systems so there is no one correct setting. Also I have found that it is not a good idea to load a cartridge, as it is like putting a lot of weight in a car compared to driving the same car without any weight fitted. As you will know the car performs much better the lighter it is- same sort of thing with loading really.The more you load the cartridge the worse it sounds. Also the Seven is AC loaded so there is no harmful DC component interfering with the fragile cartridge coils so it is allowed to perform at it best without external influence. TW Acustic did some experiments with different loading values on the Seven and found it made no difference at all."
My Allaerts "845" ohm is paired with the "117" ohm Seven and is a great match.

>>As you will know the car performs much better the lighter it is<<

That's a bad analogy. The car may accelerate faster but not handle as well without proper weight and weight distribution.

I hope Ralph addresses the other technical errors and misunderstandings in your post.

Jloveys, when you can measure a thing in audio, and also hear the same thing, then you have a powerful correlation that cannot be denied. Critical damping of any inductive device, whether it is a coupling/setup transformer, phono cartridge or tape head is an excellent example of such a correlation.

Putting a resistor across an inductive device to effect Critical Damping is quite beneficial. Harmonic distortion is reduced, revealing more detail while simultaneously producing a smoother sound, and bandwidth is extended while simultaneously flattening the frequency response curve.

These effect are easily demonstrated by measurement and listening tests. As an example I've included a link to the Jensen transformer website; Jensen is one of the world's leading manufacturers of MC step-up transformers (and other transformers as well; they have been in business for decades). On the page of the link you will see a pdf that can be downloaded that shows the various loading values to be used depending on the phono cartridge in use.
http://www.jensen-transformers.com/mc.html

Whoever you were communicating with regarding this issue is misinformed and missing out on getting better performance.

A Formula one performs better than a truck :-)

Jloveys, that might be true on a track. But trucks are intended for use on the road, something that Formula cars suck at- their engines are not tractable since they are intended for power at high rpm. Additionally, many trucks will handle and ride better with a bit of a load...

Do you see now that its not a good analogy? If you want to use cars as an analogy, an unloaded cartridge is like a car with no shock absorbers- it will ring (bounce) and oscillate with any input. A loaded cartridge is like a car with tuned gas shocks- the output will reflect only what is on the surface of the LP.