Hi Dave,
uff, let me try this. You are right that a higher output voltage (at the secondary) would come at the cost of a lower current --- IF you would not be able to DRAW more current through the cart coil, but you can. That is the WHOLE point.
As to the 47 ohm 'natural impedance' (on primary), I though to have said impedance! Sorry that was a typo, need an editor, methinks. Thanks for pointing it out.
The 10.18 ohms is also impedance since it is in parallel with the reflected secondary impedance of 47 ohm on primary, calculation as we know.
The next item is explained also by drawing more current, as I said on top. You are going into a 10.18 ohm impedance rather than some 100 to 47k! Take your pick, what ever your 'normal' loading would have been.
A cart is actually a 'floating' device, XLR floating, NO ground. So NOTHING is shunted to ground only +/- at least in one of the better scenarios.
>>> The other extreme of this is a situation where a 10 ohm resistor is placed on the primary side of the transformer and the secondary is left open. Then all of the current generated by the cartridge will traverse the 10 ohm resistor and virtually no current will traverse the transformer <<<
That is right on the money, next to nothing can then go through 47k pre-input-impedance...
Yes, and all the parasitic etc., of course but that is actually for the practical reason negligible.
The main point you are missing here is that 20 times the voltage i.e. 6.8mV instead of 0.3mV into 47k pre-input-impedance, WILL and DOES 'pull' more current on the primary side which has ONLY 10 ohm impedance! A virtual short circuit!!
Well, I could go on but let's see if that makes any sense now.
Greetings,
Axel
uff, let me try this. You are right that a higher output voltage (at the secondary) would come at the cost of a lower current --- IF you would not be able to DRAW more current through the cart coil, but you can. That is the WHOLE point.
As to the 47 ohm 'natural impedance' (on primary), I though to have said impedance! Sorry that was a typo, need an editor, methinks. Thanks for pointing it out.
The 10.18 ohms is also impedance since it is in parallel with the reflected secondary impedance of 47 ohm on primary, calculation as we know.
The next item is explained also by drawing more current, as I said on top. You are going into a 10.18 ohm impedance rather than some 100 to 47k! Take your pick, what ever your 'normal' loading would have been.
A cart is actually a 'floating' device, XLR floating, NO ground. So NOTHING is shunted to ground only +/- at least in one of the better scenarios.
>>> The other extreme of this is a situation where a 10 ohm resistor is placed on the primary side of the transformer and the secondary is left open. Then all of the current generated by the cartridge will traverse the 10 ohm resistor and virtually no current will traverse the transformer <<<
That is right on the money, next to nothing can then go through 47k pre-input-impedance...
Yes, and all the parasitic etc., of course but that is actually for the practical reason negligible.
The main point you are missing here is that 20 times the voltage i.e. 6.8mV instead of 0.3mV into 47k pre-input-impedance, WILL and DOES 'pull' more current on the primary side which has ONLY 10 ohm impedance! A virtual short circuit!!
Well, I could go on but let's see if that makes any sense now.
Greetings,
Axel