Shelter 901: Optimal Impedance

Thanks Sean. Am I correct that no capacitance should be used? It doesn't reference any setting in the instructions.

Sarcher is right, it's system dependent.

I would just try all the available settings. I found that for my cart, the midrange popped into focus at a certain setting, and it was quite a bit higher than the value everyone else was using.

If you have to supply your own resistors, I'd try maybe 3 resistor values, like 1000, 500, 100 Ohms.

MC carts *shouldn't* be sensitive to capacitance, but you might want to try different capacitive loading anyway, or tonearm cables with lower capacitance.

While it's true that it's system dependent, 100 ohms is the place to start.

Shelter dealer.

I've owned a Shelter 90X and currently use a Shelter 9000 and have found 38 ohms to work best for me (my phono pre uses transformers). The Shelters do seem to share some family characteristics. One easy way to determine optimum loading is to decrease the resistance (increase the load) until the soundstage collapses then back off one setting. Some like to run their MCs wide open. Maybe their high freq. hearing is shot or maybe they like to listen to surface noise. Anyway, play around with it and see where you like to run your MC. That's one of the nice things about this hobby. You can set up your system to sound the way you like.

The internal impedance of the Shelter 901 is 20 ohms and the rule of thumb I use is to start with 10 times the internal impedance, and adjust from there. I am using my 901 at about 180 ohms and am happy with it. The specs say 100 ohms but I found that it stifled the high frequencies a bit. When you go higher, it opens up the high end, but with some bright cartridges like the Denon 103R, it gets too bright. When you go lower, it deadens the high end and sounds like it is choking the highs. Some call it a muddy and flat sound. I personally haven't found a problem with going with a higher impedance on the Shelter 901, so 470 would probably sound fine. It is always better to go higher than lower.