The Bellari PA 555 is a remarkable vacuum tube preamplifier. It features a 12AX7 tube operating at 150 volts. The input signal directly connects to the tube's grid, and all the gain comes from this high - quality 12AX7 tube. With no feedback circuit or integrated circuits in the audio path, it offers a pure analog sound experience. Its technical specs are impressive: 10K ohms input impedance, a max output gain of 11.1 dB, 0.1% THD, a 103 dB unweighted S/N ratio, a frequency response from 5 Hz to 198 KHz within +/- 3 db, - 75 dB crosstalk, and 100 Ohms output impedance.
Using the Bellari PA 555 preamplifier is quite straightforward. First, connect your input signal source to the preamplifier. Make sure the connection is secure. Then, you can start adjusting the gain as needed to get the desired output. When it comes to volume, start at a low level and gradually increase it to avoid sudden loud sounds. As for maintenance, keep the preamplifier in a dry and clean place. Avoid exposing it to extreme temperatures or humidity. Check the tube regularly for any signs of damage. If you notice that the sound quality starts to degrade, it might be time to replace the 12AX7 tube. Also, be careful when handling the preamplifier as it is a delicate electronic device.
