Question about Cartridge Loading

Hello All,

Out of all the different audio components, seems like the phono amp is still something that I am trying to understand.

I have read much about it here on the forums, google and YouTube.

But I haven’t really come across a simple answer as to how different resistance (ohm settings) affects the sound and that is what I am trying to get to and understand.

I have very basic electrical knowledge but understand that the different cartridge loading values: 100, 200, 300, 47K, etc are different values of resistance.

By the way, I understand Gain. Higher the Gain, the louder it will be (ever so slightly).

Also, I am not worried about capacitance settings since I use a MC Cart.

So, in the most simplest terms, what I want to understand is if for example, if a 100 ohm setting is chosen on a phone preamp, does that mean the audio will be more open because there is less resistance compared to say a 600 ohm setting?

Would 47K damp the sound even more because it is a higher resistance value compared to 100 ohm.

In my mind, resistance means to push back or down, so I would think a lower ohm setting mean that audio output would sound more free/open not as veiled, perhaps more bass.

Am I thinking about this the correct way?

I know it’s probably not as simple as that.

Currently, I can’t seem to detect much different in the different load values with my phono pre-amp.

Anyways, any feedback would be welcomed.

As I said, I am looking for simple answers like: lower ohm setting equals more open sound and higher ohm setting equals more veiled sound (I’m sure I am totally wrong about that as there are many variables involved).




Dear @hagtech  : Yes your link/calculator is really great. I wish that the LOMC cartridge manufacturers includes the cartridge inductance in its specs that's need it in your calculator.



For LOMC cartridges, where the typical inductance is less than 50 micro-Henries, and often much less than that, does it really matter much to include inductance in the calculation?  I doubt it.  We saw a month ago that for the low output MI cartridges like Sussuro, which has an internal R of only 10 ohms, inductance surely does matter, because it's about 1000X higher than for a typical LOMC.

My Pure Fidelity Stratos (based on the Gold Note Donatello) has a 45 ohm impedance and recommends loading between 400-500 ohm (figuring 450 ohm to be optimal?). However I haven’t really heard any difference between 100 ohm and any variation between 400-500 ohm. 

What I did on my JC3+ phono stage was set the variable dials to 450 ohm and then flipped the switches between MC Variable and MC 47K and that’s where I actually noticed an improvement. At 47K the soundstage is wider and deeper with no detrimental effects that I can hear on top end, harshness, or bass, so that is what I’m sticking with. 

I am guessing a lot of this must be system-dependent because according to the manufacturer I should get optimal sound between 400-500 ohm but according to my ears I can’t hear any differences or improvements until I load it all the way at 47K. 


It's not that 450 ohms is "optimal".  It's that you want the phono stage input impedance to be at least 10X the internal impedance of the cartridge.  In your case, 10X = 450 ohms.  So any input impedance equal to OR GREATER THAN 450 ohms would comply with the conventional wisdom.  If you don't hear a difference between 100R and 450R, I suggest you try 1000R or even 47K.  Also, check the VTA for your cartridge.  If the tonearm is not level with the LP surface, is the pivot lower than the headshell?  That can cause loss of HF response.  Also check for any number of other things that can affect HF response.

Dear @lewm  : The OP cartridge was reviewed and the reviewer said performs just fine at 100 ohms that's is way out of your 10X rule. In reality it's not a rule because I experienced several cartridges below that with very good listen sessions.  

Btw, "  does it really matter much to include inductance in the calculation?  I doubt it. "  Do you already make your job using Hagermann calculator at least with 6-7 different examples?  if not then maybe time for you can do it and confirm that " doubt " you are talking about. Don't you think?