Cartridge output matching to phono stage.

Thanks for the reply. I understand this better now.

Mike

a step-up of 20dB will not be enough for the phono input with input sencitivity of 4.5mV. The preamp section will not be having the specified gain and output parameters if you feed a voltage less than input sencitivity.
A step-up transformer with 30dB of gain will be more appropriate but might be very expencive. The times gain will be approximately 32 which will give you ~7.5mV -- an ideal case.
If you will have 23mV you will less-likely overload since most of the phono section can handle upto 100mV. In this case you will be operating in the low volume positions that mean that preamp section is working in attenuation rather than amplification which is considered to be better. The signal might get compressed but it's usually for high gain stages that DO require to use the low output cartridge but your phono section has no-more probably than 35dB i.e. times ~60

That's amazing, I was looking for an answer to this question this morning. I think I get it but do not quite understand everything. If I have a cartridge with .23mV output and I use a stepup transformer with 20dB of gain, then it will have an output of 2.3mV. If it has 40dB of gain then it would have 23mV, and if it had 60dB then it would output 230mV. I have an old Fisher 400 tube receiver with a phono stage that needs 4.5mV on its input (I don't know if this is minimum or what). If I had a stepup with 40dB of gain, wouldn't this overload the input of the receivers phono stage? Or do phono stages (as well as other inputs) accept a wide range of input voltages? If I used a stepup with 20db of gain (2.3mV) with this phono stage (which needs 4.5mV) then will I only get half the volume out of the phono stage or would it just have a lot more hiss?

You're getting some number approx 10^2*sqrt(10) which gives you approx 300 times and doing wrong nothing. So you're getting an approx output voltage of 240mV. Now you should check specs of your preamp in terms of input sencitivity which has to be bellow 240mV and moderate gain of 10...15dB. Otherwise I would pickup a high output version of the same cartridge for its maximum performance.

Happy Listening,
Mara.

Marakanetz, Thanks for the responce, but now I am confused. For example, I have a Conrad-Johnson PV10B tube phono stage at 48.5 dB of gain. The cartridge I wish to purchase is a Benz Glider at 0.8 mV. When I multiply gain by voltgage I get 38.8, well below 500mV. What am I doing wrong?

Regards,
Lou

it's a very simple arithmetics.
all you have to do is use the following formula to transfer gain from dB to times:

1. 20Log(times gain) = dB gain

2. times gain = 10^(dB gain/20)

"^" sign in the formula bellow represents power of an argument 10 in our case.

thus if your phonostage has a gain of 60dB than using second formula you should bring 10 to the power of three 10^3 = 1000 times i.e. 60dB = 1000 times.

You should always multiply the gain by your cartridge output and get an output voltage arround 500mV or higher.
A phonostage with 60dB gain can be used with the cartridges as low as 0.5mV on the output or higher. A phonostage with 40dB of gain(100times) can only be used with 5mV or higher etc...

I suggest to pick up phono that have at least 50dB of gain.

Sometimes it's enough(depending on the preamp sencitivity) to have the output of your phonostage 200mV or even bellow but that you will have to check on the preamp specification.
For low gain or zero gain or even passive preamps hold up to 500mV or higher.