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

Whoever warned you about a “peaked high end” was wrong. 47K is just fine for a low output MI.

Actually my Hyperion has been used with 47K since forever.  It just sounds better.

Hmm. I'm not alone. Any other Hyperion users like to chime in with their loading?

@dogberry 

 

I agree with Lewm and Billstevenson on loading based on practical hands on experience using both; the SS Hyperion MK II and new SS Hyperion MK II MR.

I initially loaded the Hyperions’s per the manufacturer’s recommendations and not long after discovered through listening that changing the loading increased listening pleasure. From my observations, I heard better resolution and less midrange shoutiness, or excessive peaks…it seemed to balance out and improve performance with these changes in loading.

My process to come to this conclusion is somewhat similar to how you started. I initially started at 400 ohms and then did a giant leap to 47k ohms. This was to interpret gross performance differences between the two loading ranges. After experimenting with those two loading ranges, I opted to try 1k, 4.7k, and 10k. I also dipped down to 243 to see what sound differences I could discern. I have an Aesthetix IO Eclipse phono stage with dual power supplies which allows for those loading values. I actually can go as low as 10, 20, 40.2, 75, 121, 243, und weiter. 
 

The realization is that I was able to come to the final loading ranges based on experimenting with the different loads my phono stage allowed me to use. I arrived to the 47k range after listening to all the other loads and concluded that 47k was perfect with the two different Hyperion models. Always take the manufacturer’s loading range as a starting point and experiment through listening and alternating between other loading ranges to get the best balance in sound. 
 

I do not find the Hyperions having any peaking attributes on the high end with 47K loading. I have an Air Tight Opus 1 which I do find to be more restrictive to the manufacturers loading range; however, that cartridge is a low output MC cartridge and not the same type of construction as the Soundsmith cartridges. I only mention this as once you acquire various cartridges and experiment, you too will come to similar conclusions. Have fun listening. 

Looks like we are gravitating towards higher loading values. Anyone else have one - and what do you use?

1. Hyperion MK II : loading 47k 

2. Hyperion MK II MR : loading 47 k 

 

Both sound excellent. See post above. 

Can you guys confirm when you say you are loading your SS cartridges at 47k are you going into a MC input then loading at 47k. I thought most MM sections are all 47k ohms. 

Whatever input offers enough phono gain. Both my balanced phono stages offer 47K ohms into high gain RIAA circuits. One came that way. One I modified myself.

Yes 47kΩ on an MC input. You're right that MM inputs are almost always 47k, and are often fixed at that.

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.

@lewm 

Simply working the inductance against the load impedance is too simplistic of an assessment for the use of a SUT in the case of MI (or other high L ) cartridges.  What becomes more important is the load capacitance reflected through the transformer resonating with the inductance creating problems near the top of the audio band.  assuming a 1:10 and 150pF of load capacitance and 2.75mHy of inductance we get a resonance @ 25kHz.  The 47kΩ does a lot to damp this resonance but being so close to the top of the audio band makes me nervous.

 

dave

Dave, I hope I didn't claim to know exactly why inductance is the problem with using the SUT, only that it IS a problem.  I did understand it has something to do with HF resonance, but I guess I left open the incorrect interpretation that it has to do with the cartridge trying to drive the resulting load. Thank you for the explanation. I think Atmasphere has said the same. Based on reports here from users of the low output Soundsmith MI cartridges, Peter Ledermann is not against using SUTs with his cartridges but probably only ones with a turns ratio of 1:10 or less.