Impedance Loading for SS Hyperion


"470 - 1000Ω" says Peter Ledermann. My phono stage offers 400. 800, 1,200. so I used 400 initially (extremely smooth), decided 800 was better (some edge present) and 1.2k even better still. There is one higher setting allowed for the MC input (along with several lower ones), 47k. So I’m trying it, and I like it. I keep swapping to the London Reference I am comparing the Hyperion to, and it seems the higher the impedance loading, the closer they sound. I am not experiencing the "peaked high end" I was warned of if loading is increased over 1000Ω.

Maybe my half a remaining ear (thanks, streptomycin!) simply can’t hear the cartridge screeching. Might work for others with high frequency loss? I think the issue is that I have a powered sub that is making sure I hear some bass whatever the loading is set to. If I turn it off the Quad 2905 speakers alone don't sound as if I'm listening to the full range of sound. Perhaps I should set the loading without the sub, and then do my usual procedure of setting the sub volume so I cannot tell that it is switched on, but all the same things sound better?

dogberry

I can use a MC input and load it to whatever value I want, or use a MM input which is what I use when I use an SUT.  The latter is my most often chosen approach. 

Is that with a Hyperion, Bill? Using an SUT, as I expect you know, the resulting loading will be 47,000 ÷ turns ratio² = load (assuming you have a 47k MM input).

Yes with my Consolidated 10:1 it would be 470, with my Bob's devices 5:1 it is  1,880.  With no SUT it is 47,0000.  My phono stage works any of these.  

Because low output MI cartridges have much more inductance than comparable LOMC cartridges (as much as 1000X more inductance), 470 ohms is about as low as you want to go, which limits the typical system to using a 1:10 SUT where the SUT drives an MM stage with a 47K input Z.  This even though the SS and Grado LOMI cartridges have an internal resistance of 10 ohms or less. I'm sure Bill knows this, just saying.