"Patrick Turner" ha scritto nel messaggio
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I have used a 6DJ8 with a passive RIAA, followed by a 12AX7,
so total gain at 1 kHz is 30 x 70 /10 = 210, and the
divide by 10 is the loss at 1 kHz of the RIAA filter.

So if you have a 5 mV @1kHz cart at 1 kHz, you just over 1,000 mV at the
output.
But a cart of 2,5 mV, and a second phono stage gain of 35
would still make 250 mV.
But not so good with a Denon 103 MC, whose output is only 0.3mV.
Then you need more gain, or a step up transformer.

Maybe I don't do the calculations right:
MM cartridges usually have around 4mV rms output voltage and I must have
about 2 Vrms at the phono stage output to match the max output of my CD
player.
Considering about 20dB (maybe 30?) over the nominal 5cm/sec level for the
higest music peak in the vinyl, I have 40mV coming out from the cartridge.
Ergo I need an amplification factor of at least 2/0.04=50, wich becomes 500
considering the nominal 20dB loss of the riaa network.
A EC8010 followed by a 76 should do the work, giving a gain of 600.
Maybe the output impedance of about 9kOhm can be a problem. Should i add a
CF?