[plastico]

I am currently running a Denon DL 301 mk2 with a Denon AU300LC SUT on a RB300 arm. I will be getting an Audiomods arm very soon, and my mind is starting to wander and wonder about better carts. I was thinking about getting a Dynavector 17D3 in the future. Hell, I don't even know what the Denon is going to sound like! But, there is always the upgrade urge since this arm is going to be fantastic! So, will the Dyna work with my Denon SUT?
Cheers, Plastico

[Maritan]

I quickly looked up the Denon SUT, but can't see if it has loading options. If it does, what's available?

Also, what is the load impedance of your phono stage that the output of the SUT plugs into? What is the gain of the phono stage?

These will help you determine if the 17D3 will work with your SUT.

[plastico]

It's a 10x tranny, with 3-40 ohms loading. Phono is a Grant Fidelity P-307 with 42db of gain, and 47k ohm input.

[Maritan]

Yes, your SUT has a step up ratio of 1:10.

3-40 ohms loading seems to contradict what I saw on LPGear. The 3-40 Ohms spec was recommended cartridge impedance. Do you have a switch or knob that allows you to change the cartridge loading?

Anyway, with the given and information and some maths, here's what we end up with:

At a load of 47k on the output windings of the SUT, your cartridge sees a reflected impedance of 470 Ohms. This is higher than the recommended load of 100 Ohms for the 17D3. The 17D3 checks in at 38 Ohms impedance so it falls inside the recommended cart loads for the SUT. The output of the 17D3 is only about half of your Denon though - 0.23mV vs. 0.4mV.

Doing some very rough calculations, keeping the load that the cart sees to 470 Ohms, for the 17D3 you will be getting an output at the SUT of roughly 2.1mV. Given a gain of 42dB with your phono stage - that translates to 126 times input voltage your preamp will see about 270mV.

With the Denon cart, you are seeing 3.7mV output at the SUT and your phono pre outputs 470mV.

Feel free to double check my calculations. I've been known on more than one occasion to make careless mistakes.