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Will our MC for the festivities gain the stage?

Those of us who own preamps with phono stages are familiar with the phrase, “will handle MM cartridges and most MC cartridges”. The word “most” becomes critical when considering many of the low-output pickups available. My Kora Eclipse, for example, has separate MM and MC inputs and the MC stage is rated at .4mV/100ohm with a gain of 55dB. At what point is that 55dB gain insufficient to handle EFFICIENTLY a very low-output pickup? .5mV, .6mV? I know that it does depend upon actual output of the pickup and there are no hard and fast rules. I was given the following general guidelines some time ago which I post below. Does this seem like a good “rule of thumb” or is someone prepared to give it the finger, instead? Thanks.

0.2-0.5 mV needs 63dB gain
0.6-1.9 mV needs 50dB gain
2.0-5.0 mV needs 37dB gain
4yanx
twl
3,251 posts
 
David, as Marty pointed out to me in another thread, it will be the phono stage gain combined with the line stage gain that will be the key to this.

My MFA Magus preamp has 46db gain in the phono, and 20 in the line stage, making a total of 66db gain for the entire preamp system. This was not sufficient for the Shelter 501, and I had to resort to using my Cotter step up transformer. The Cotter gave a 20db boost, to bring the total gain to 86db, which is now more than sufficient, and I can only open up my volume knob to about 9 o'clock before I am at full volume. I think with the Shelter cartridges, you will need at least a good 75db total gain in the preamp system to handle this properly.
4yanx OP
1,576 posts
 
I am not sure what I am geting from the line stage, Tom, but I will check. But, if I am getting the same 20dB as you are, then I would have a total of 75dB and be in the same "league", no?
twl
3,251 posts
 
Yes David, if your line stage provides 20db gain in addition to the 55db in your phono section, you'll be in the ballgame.
Post removed 
twl
3,251 posts
 
Marty, I tried using the Shelter at 100 ohms, which is about the best load I found for it. It just didn't have enough "oomph" with my MFA preamp(66db total gain). The Shelter doesn't do as well when it is unloaded, in my opinion anyway.

I am hoping that David can get enough gain to get the right result with the 100 ohm loading that seems to work best with the Shelter. He is primarily talking about the Shelter cartridges in this question. I know, because we have talked off the forum about this.
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