• 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.

lazarus preamp hums even with volume down and no components connected.

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I'm not sure where you get that from. The Wima MKP are polypropylene caps. That's one of the lowest loss dielectrics and the one that contributes the least to distortion.

~Tom


I've notice when used in high impedence circuits ( tube circuits mostly) they have too much inductance that messes with the miller capacitance of the tube (inter electrode capacitance)

the dielectric is correct. But their construction techniques is flawed.

the balanced outs seem to have been modified weather it is an OEM mod, I don't know. I don't remember those wires when I looked at one many years ago.
 
Ah crap i just looked over the pics. The wad of 3 zeners is a voltage reference. He tripled them up because zeners cant handle much current. From what it looks like, those are used to make a high voltage regulator.

That being the case you need to find the voltage of the zeners and replace them with the same voltage.


HeadWize - Project: Designing an Opamp Headphone Amplifier (A HeadWize Design Series Paper)


Odds are its something like figure 20. So what ever those zeners are, is what the regulator is going to put out.

Zener Controlled Transistor Voltage Regulators - Electronic Circuits and Diagram-Electronics Projects and Design
 
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