2. analog
  3. 1261350841

Convert cartridge output voltage to db gain

Happy holidays everyone. I hope that you may help me with a problem. I have re-configured my system, preamp and amp gone, I'm now using a integrated amp. I still have my phono stage and cartridge. My cartridge has a 0.24mV output, my phono stage has 66 db of gain. This used to sound fine, but now I notice that the noise floor is too high for me. So I'm debating on whether to look for a higher gain phono stage, or more likely, a higher output cartridge.

So now my question, how much more output would give me how much more gain? Should I be looking at a 0.5, 1.0 or 2.0+ mV output cartridge? I think I need at least 10 db more gain, and there are not many 76db+ phono stages out there. So what do you analog experts think? Is there any table out there that can show me how to convert voltage output to gain increase? TIA.

Cheers,
John
jmcgrogan2

Showing 2 responses by jafox

jafox
1,467 posts
 
Actually, the equation is: db = 20Log10(Av), where Av is the voltage gain (Vout/Vin). Vin is the input signal (your cartridge output of 0.24mv) to the phono stage. Ultimately you want a line level of 0.5 to 1.0v from the phono stage's output to match the same same level from the CD Player.

If you are aiming for 0.5v output from the phono stage, Av = (0.5v / .24mv) = 2083.3 Plug this into the "db = " equation and you have a db value of 66db, needed by the phono stage to achieve that 0.5v signal into the line stage.
jafox
1,467 posts
 
Congratulations John. Good to hear the noise is gone.

I had serious hum issues with my system when I used the Jade Hybrid IC (unshielded) from Counterpoint head amp to Aria preamp. I quickly learned that only a shielded cable would work here. But so many ICs were destructive to the musicality of the system.

I too tried a Chinchilla IC and it was much better than the MIT 330, but still I was disappointed. Finally, I ended up trying the awesome Silent Source Silver Signature sent to me from Lloyd Walker. The hum was gone and the sonic result was VERY impressive. I got a little more upper detail but a slight loss to the spatial attributes that I had with the Jade. Ultimately JD tweaked his IC for me as he grounded the carbon-fiber jacket to the casing on the RCA connector on one end. That did the trick with the hum issue. The Jade IC was now usable. Ultimately I kept the SS cable in this link as the little more detail was attractive. But jumping to the new Jade Ref IC changed everything. Wow! I hope you get a chance to hear this one day.

John
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