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.
I have a 12AU7 preamp. From an article in this diyaudio, I change 12AU7 into 12BH7. <p>Wow, I feel wider sound range and more linearity. <p>However, I hear more white noise....I think it gives more gain.<br>Do I need to change Rp for original 12AU7?
Usually U7 and BH7 can be exchanged without any change to the components value, special in a preamp, however, have you checked the BH7 is noisy or not?