Cartridge loading


Presently I am using a ZU/Denon DL103 mc cartridge with ZU Audio's highest tolerances.  I had this cartridge mounted on my VPI Prime and after going through all the various loading combinations, I settled on 200 ohms.  I was always satisfied with my choice of setting.  I no longer have the Prime and now use the Technics SL1200G turntable.  After having the same cartridge mounted and aligned by the dealer, I inserted it into my system and enjoyed the sound immensely, never touching the 200 ohm setting.

Yesterday I was listening to vinyl most of the day and for some reason I found the sound to be better than ever, mostly in the treble area.  The highs had shimmer when needed and I had played the same records many times before on the Prime and they never sounded as good as they did yesterday.  Just for the heck of it, I checked the cartridge loading and found it was now set at 1000 ohms.  As I said, when I put the Technics into the system, I never bothered changing the loading which was at 200 ohms as it was the same cartridge, just a different turntable.

I believe I know what happened, when I last used the tone controls on my McIntosh preamp, (you have to shuffle through a menu) I must have inadvertently put the cartridge loading at 1000 ohms.  It truly sounds fantastic, better than I ever thought possible.  The Bass is still very deep and taut, midrange is the same but the treble, oh my, so much better.  Now the million dollar question is why should it now sound better at 1000 ohms, when it sounded great before at 200 ohms?  Can the tonearm on the Technics have an effect on cartridge loading?  I always thought it was all dependent on the preamp, amp and speakers.  What am I missing here?  I am very curious to know.  The specs for my cartridge say greater than 50 ohms for loading.

Thanks
128x128stereo5
@stereo5 47K is the standard for phono cartridge loading. 
I am very happy at 1K ohms, I was just kind of wondering why.

I explained why in my prior post. With a higher impedance load on the cartridge, the cantilever is more able to trace high frequencies.

What @atmasphere writes is very much what is causing your change in sound character. Loading at the phono stage and not at the cartridge is what you should be looking for. Also what phono cable are you using and do you know its capacitance? A very low cap cable should be what you use along with a higher resistive setting at the phono stage (like 1000 ohms) then you allow the cantilever to move freely in the groove, rather than a low resistive setting might stiffen the cantilever and make the cart work more.
If I load my Delos at 100 ohms the sound is closed, restrictive and bland, I load at 475 ohms and the sound becomes very dynamic and very high resolution.
The Zu Denon is very much a "salt to taste" kind of cartridge when it comes to loading.  When I used one it could indeed sound quite different when using 100/200/300/500/1000 ohms.  And Zu will tell you there is no wrong answer here, just use what sounds best to you.