Hi Al,
you quote Gundam91: "The first rule of thumb is that most (some exceptions exist) MC cartridges like to see a load impedance of 3X to 6X their output impedance value."
This is entirely dependant on the cart DCR in the first place.
Note: The lower the cart DCR, the closer the actual cart impedance to the cart's DCR value.
What you actually try to do is to get an impedance match 1:1 between cart and primary. This way you double the current from the cart in lieu dropping it’s output voltage. The cart is working in: ~ 'current mode'~, which in turn provides for the best and highest voltage output on the secondary.
Very often this coincides very closely (also in experience) with the lowest quoted "recommended" loading.
If e.g. a cart it quoted as >10ohm (at a DCR of ~ 4ohm) or say >30ohm (of DCR ??) etc., then this often turns out to be your point of departure.
Caveat! If a ~ 6ohm cart is e.g. quoted >100ohm then it is VERY probably targeted only at a non-SUT load.
You could see what I mean when visiting some of the Lyra specs (on web) and will see that they actually quote 2 values - one for normal (non-SUT) and one loading for SUT.
Usually some ~ 10:1 difference
Greetings,
you quote Gundam91: "The first rule of thumb is that most (some exceptions exist) MC cartridges like to see a load impedance of 3X to 6X their output impedance value."
This is entirely dependant on the cart DCR in the first place.
Note: The lower the cart DCR, the closer the actual cart impedance to the cart's DCR value.
What you actually try to do is to get an impedance match 1:1 between cart and primary. This way you double the current from the cart in lieu dropping it’s output voltage. The cart is working in: ~ 'current mode'~, which in turn provides for the best and highest voltage output on the secondary.
Very often this coincides very closely (also in experience) with the lowest quoted "recommended" loading.
If e.g. a cart it quoted as >10ohm (at a DCR of ~ 4ohm) or say >30ohm (of DCR ??) etc., then this often turns out to be your point of departure.
Caveat! If a ~ 6ohm cart is e.g. quoted >100ohm then it is VERY probably targeted only at a non-SUT load.
You could see what I mean when visiting some of the Lyra specs (on web) and will see that they actually quote 2 values - one for normal (non-SUT) and one loading for SUT.
Usually some ~ 10:1 difference
Greetings,