SUT - electrical theory and practical experience

@drbond A well rounded assessment of your created thread to date, and I do agree the Rothwell Info' provided, has been very valuable entry, as well as, a very worthy point of reference to be found within this thread. It assisted with your own requests for further information and certainly will assist to others as well. 

I also feel @mulveling has offered a useful input to those showing interest, and looking to gather a understanding of the usage of the SUT as a Device. 

The Rothwell Info' certainly presents in a manner where the information is approachable by multiple individuals (where like yourself ) have a developing interest in the subject matter. I have also been pointed to this Rothwell Info' in the past, by a very adept EE who designs and builds. With this Info' on offer from Rothwell being suggested to be visited, I can only presume it has a content that lens itself to being accepted on this section of Electronics.

In your most recent post, the last paragraph, is the area where this thread has caused a concern for myself, and the one that is the encouragement that has prompted me to avoid the evolving discussion. 

This attitude to avoid, is due to the fact the countering from differing parties to the developing discussion evolving, is already convincing enough to suggest the Thread is now on a route of Conjecture/Theory and the outcome will be as far from a Theorem as can possibly be. There is nothing seen to substantiate the avenue of investigation as having a end result that can be relied upon.

I have no desire to see inaccuracies spewed out, that are already evolving into a topic that is quite confusing, especially to how the value of the extension of the subject will be beneficial to anybody if loaded with inaccuracies, as the counter presentations are highlighting. It does seem a contribution is supported by outsourced information, as means to help substantiate the meaning within the post. There is nothing being presented to stimulate a desire to learn more, as the endeavour is seemingly to come to nothing.  

Questionable content, is only going to achieve one outcome, which will be to taint a very good thread, especially one that in my view, serves as a reference point for the future to others.

Theorem, Theory, Conjecture, Ideas. I know which I am leaning toward as the foundation of the majority of posts in the last few pages of discussion in this thread.       

n your most recent post, the last paragraph, is the area where this thread has caused a concern for myself, and the one that is the encouragement that has prompted me to avoid the evolving discussion. 

This attitude to avoid, is due to the fact the countering from differing parties to the developing discussion evolving, is already convincing enough to suggest the Thread is now on a route of Conjecture/Theory and the outcome will be as far from a Theorem as can possibly be. There is nothing seen to substantiate the avenue of investigation as having a end result that can be relied upon.

@pindac I am only trying to find a way to load the cart for my 1:4 SUT.
So that CBS square wave record may be helpful..or maybe not… I’ll find out.

But I do admit that I like to know what, say, a SUT is doing… like on a plot…
If it helps me to get it loaded right, then all is good. And if not then I will also know that.

In any case, I wish everyone on the thread from @drbond OP right through to your last post, a happy holiday season.
Felix Navidad

Holmz, you ought to visit the Jensen Transformer website. There you will find erudite discussion with schematics and other data regarding how to load a SUT. Plus the engineers there are nice guys who might help with your specific questions, if you call them in California. 

@holmz 

I am only trying to find a way to load the cart for my 1:4 SUT.

This seemingly simple statement is the basis for much of the confusion that exists around SUT's in general.  People feel the need to lump similar things together hence the discussion of transformer and cartridge loading in the same breadth.

This seemingly simple statement is the basis for much of the confusion that exists around SUT's in general.  People feel the need to lump similar things together, hence the discussion of transformer and cartridge loading in the same breadth.

From a cartridge loading perspective, people consider the transformer to be ideal, at which point a simple calculation nets a "nice clean" load for the cartridge.  The problem with this approach is that transformers are far from ideal and varying both the source and load values has a profound impact on both the measured and sonic behavior of the SUT.  This gave rise to the engineering approach as shown by Rothwell, Jensen et al focuses solely on the behavior of the transformer for a given situation.  The goal here is to set the source impedance to that of the cartridge and then adjust the secondary termination (load) to get the "best" response.  The problem here is this method provides a singular "load value" for a given cartridge impedance.

What is one to do when the two approaches listed above push you in opposite directions? Menno Van Der Veen acknowledged this and noted that after the proper secondary termination is determined, the load the cartridge sees can be further increased by placing resistance across the primary (ie to the cartridge directly).   Since this only lets the load be modified to a lower value, it is a step in the right direction (and the method I suggest for additional load) but does not represent the simple solution everyone craves.

When these two lines of analysis which use all the same terms are co-mingled in a discussion like this, people tend to form "technically correct" opinions which sit on a solid foundation of bad data.   

dave