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Old 09-15-2018, 01:51 PM
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Quote:
Originally Posted by Cajunpepe View Post
OK...I got it now. So the MM stage is set to 47k with variable capacitance settings. That being the case, would changing capacitance setting among the 50pF to 750pF range alter the sound using a step-up with a MC cart? Is there a better setting (mathematically speaking)? The carts internal impedance is 14ohm, and I am using a 20:1 ratio for the step-up. Thanks again for the replies—appreciate the help and explanations.
Hi there! With your 20:1 transformer your Denon cartridge will "see" a load resistance of 117.5 Ohms, slightly above the 100 ohms or more that Denon recommends. This is because the impedance in a transformer changes as the square of the turns ratio. 47,000 / 400 = 117.5.

Likewise the cartridge will 'see' the capacitance of the preamp and cable combination reflected by the transformer. The resistance of the cartridge is so low that all the effects of the cable and preamp capacitance will be well above the audio frequency range.

Mathematically use the lowest capacitance possible.
But, hey, why not experiment to see which setting you like the best?

Tom
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