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.
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.