• 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.

Berning P-1 Preamp

Hi,

I am just wondering if anyone could have idea on the gain and output impedance of the Berning P1's line stage. The schematic is per attached.

This circuit seems a good performer with lots of local feedback to minimise the distortion.


Thanks in advance.

Johnny
 

Attachments

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Hi SY,

Good to hear your comment. I built the Matisse Atom line amp with some modifications to make it sounds better.

My friends love the Marantz 7 line amp and they built or building the same. I am just hoping to build another model that might be better. I have looked at the schematics of the Conrad Johnson, Audio Research, Jadis and many others. I am not excited with them much.

Do you have any recommendations???

Thank you,
Johnny
 
The main line stage section would have an output impedance of the vicinity of 1K and a gain of around 7 (17dB). Keep in mind that although the output impedance is quite low, this isn't really suitable for driving heavy capacitive loads since it the output stage won't be able to provide the current - it only has about 1mA running through it.

EDIT: Whoops, I missed the votlage divider at the output :(

So the gain provided would actually be around 4.8 and output Z probably around 8K from calculations.