• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Basic DIY Valve Phono Stage

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There's always the "classic" RCA design, which is seminal to all passive designs. You'll need to add a buffering voltage follower if a stand alone project is what you have in mind.

No matter which design you settle on, a DC heater supply is a must.



Edit: fixed typo
 

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dsavitsk said:
Is a 12ax7 close enough to use in this circuit, or is the 7025 essential?


With DC heating, 12AX7s are FINE. The 7025 is a 12AX7 with a spiral wound hum bucking heater. The current production Sovtek 12AX7LPS is a 7025 equivalent.

While you MIGHT be OK using AC heating on the 'LPS, why take the chance, when setting up a 7812 regulated heater supply is really easy.
 
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