Dave,
Welcome to the fray and thanks for a fascinating first post. Anyone who uses SUT's should pay very close attention, since their system performance will certainly depend on optimizing loading.
Your explanation of the complexities of getting it right for any particular LOMC won't make anyone think it's easy, but as you know better than most - it isn't.
When we used SUT's (about 3 years ago) we never tried primary side loading. Our BentAudio Mu's were built to make secondary side loading quick and easy, so it never occured to us to try. I now realize we may never have achieved the most optimum results possible.
You won't be surprised to hear that our results were ***extremely*** sensitive to tiny changes in resistive values on the secondary. The only way I could get satisfactory response was to double up resistors to achieve intermediate values not attainable with any single resistor. From your explanation it seems likely I was attepting to balance two interactive variables, transformer resonance and cartridge resonance. No surprise it took extraordinary measures to do it. Loading both sides might have been simpler, or at least more effective.
A friend and long time audio nut has owned literally dozens of SUT's. He always wondered what mysterious characteristic made one SUT better than another for a particular cartridge, even after turns ratios and secondary side loading were optimized. Your post may explain that so I'll point him to it. Good stuff.
In the end, as you said, truly optimizing any particular cartridge/SUT combination can only be done by trial, due to the interactivity of two resonances. But at least having an awareness of that interplay offers the possibility of starting off in the right ball park. That's a big step forward, for any gorilla.
Welcome to the fray and thanks for a fascinating first post. Anyone who uses SUT's should pay very close attention, since their system performance will certainly depend on optimizing loading.
Your explanation of the complexities of getting it right for any particular LOMC won't make anyone think it's easy, but as you know better than most - it isn't.
When we used SUT's (about 3 years ago) we never tried primary side loading. Our BentAudio Mu's were built to make secondary side loading quick and easy, so it never occured to us to try. I now realize we may never have achieved the most optimum results possible.
You won't be surprised to hear that our results were ***extremely*** sensitive to tiny changes in resistive values on the secondary. The only way I could get satisfactory response was to double up resistors to achieve intermediate values not attainable with any single resistor. From your explanation it seems likely I was attepting to balance two interactive variables, transformer resonance and cartridge resonance. No surprise it took extraordinary measures to do it. Loading both sides might have been simpler, or at least more effective.
A friend and long time audio nut has owned literally dozens of SUT's. He always wondered what mysterious characteristic made one SUT better than another for a particular cartridge, even after turns ratios and secondary side loading were optimized. Your post may explain that so I'll point him to it. Good stuff.
In the end, as you said, truly optimizing any particular cartridge/SUT combination can only be done by trial, due to the interactivity of two resonances. But at least having an awareness of that interplay offers the possibility of starting off in the right ball park. That's a big step forward, for any gorilla.