Phono cartridge noise calculator

[Conrad Hoffman]

Those seem like surmountable problems. Actually, for MC cartridges the need is to get from a very low impedance source, to a higher impedance circuit. This is exactly what the common base bipolar circuit does, yet you don't see that much either.

 

[Joachim Gerhard]

It is hard to make the input offset zero with a common base stage but it is possible.
I made such a design, the Nobrainer, that also has a thread here. I did it by making a feedback loop between the bases and the emitters. It has to be trimmed though.

 

[Joachim Gerhard]

Here is the rather simple circuit.

 

[Conrad Hoffman]

For a "no brainer" I think that took some smarts to design- I like it. Can it beat the FET circuits on noise?

 

[Joachim Gerhard]

Yes, especially in the bass. It is dead quit. You could even use specialized ultra low noise transistors and raise the current, say to 11mA. That is only of an advantage if you use a very low impedance moving coil.
The noise of that circuit will then be better then 0,3nV/qHz down to 10Hz. That is 9dB better then the AD797 that is advertised as ultra low noise.

 

[1audio]

What happened to the spreadsheet? The link is dead. . .

 

[grufti]

I'm not good with links on this forum, so let's hope this works. Give it a try.

RIAA Noise Calculator

What happened to the spreadsheet? The link is dead. . .

 

[1audio]

Thanks, that works. I could not find that page on the site.