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A question of loading...

I have just replaced my aging tube preamp with a new model. When I was using my older model with tube phono stage, I would run my Lyra Kleos and other MC cartridges with a load of 750 ohms. So, I assumed that with my new tube phono stage, which also utilizes a transformer in the phono stage and is also built into my new preamp, that the same cartridge loading would apply. I listened to the Kleos for about a week with this loading, and frankly, while it was fine, I wasn’t bowled over. Tonight I decided to experiment, so the first thing I did was to run the cartridge straight in, with no loading plugs. WOW, the increase in overall musicality and soundstage width was eye opening! Lesson learned is that not all gear is going to react the same when it comes to cartridge loading, particularly if there is a transformer involved and even if you are using the same cartridge from one phono stage to the next! An eye opener, anyone else experience something like this?
128x128daveyf
dover
2,173 posts
 
I've been running MC's into 47k since the 80's sans step up transformers. Do you know what load the Kleos is seeing at the moment ?
daveyf's avatar
daveyf OP
2,829 posts
 
@dover  At the moment, i am presuming that since I am not loading the cartridge at all, it is seeing 47K. This is what surprises me a little, as previously with the older tube phono stage sans the SUT, a straight in with no load was definitely inferior to the custom 750 ohm plug that i was using. Now, with the SUT and at 47K ( presumably) that is certainly no longer the case as the SQ is as described in my OP.
jdal
156 posts
 
I have a Lyra kleos and an Ortofon Cadenza bronze and run those with no loading into a Herron VTPH-2A. 
Soon I’m going to try a Kiseki purple heart and the recommended loading is 400 ohms but I will try it without loading plugs.
As I understand, loading is for the phono stage, not the cartridge.
daveyf's avatar
daveyf OP
2,829 posts
 
Loading is at the phono stage, but it absolutely has an effect on the sound of the cartridge. There is some belief that loading effects a MM cartridge more than a MC, but I am not totally sure this is the case.
The loading would seem to be dependent on the combination of what sounds best depending on the phono stage and the cartridge, wherein I was previously under the impression that it was somewhat cartridge dependent and NOT to do with the particular phono stage as much. Seems like it is both at this point.
dover
2,173 posts
 
@daveyf 

The reason I asked  about the actual loading on MC is because I was wondering how they got the extra 11db for the MC input. If they used low gain transformers then the actual load would be 47k/turns ratio (of the transformer )squared - which would result in a load seen by the MC cartridge somewhere between 3500 - 5000 ohms.
According to Steophile review of the Cat SL1 Renaissance MC unloaded measured 3560 ohms.
So it is possble your load is between 3 & 5kohms.

Jonathan Carr the designer of your cartridge says that loading does not affect the cartridge itself with modern MC designs, but what loading  can do is dampen any ultrasonics that might affect the phono stage ( solid state devices can have low overload margins at very high frequencies, whereas tube designs less so ). Thats why he specs out loading range  up to 47k.

In my view if you can run MC's into higher impedances without upsetting the phono its a good thing. Klyne has done this for years, they use higher loading combined with very high frequency contouring to tame any ultrasonic nasties.. you are hearing the benefit of "unloading" your cartridge.
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