Similarly to TPC-I mk2, PA501 was designed for studio recording: it connects to any type of microphone or musical instrument. The amplifier features a high-resistance input (HI Z) and a built-in phantom power supply. Like other devices of the 500 series, PA501 has a power on/off control of individual channels.

This device is the first and in our line of 500 series devices. Basic in function, anything but basic in sound! This preamp is able to outperform many similar devices on the market. In addition to delivering crystal clear sound and high gain, the PA501 can bring music to life. This is a complete tube preamplifier with input and output transformers. The ability to select the type of input signal allows you to work not only with microphones of different sensitivity, but also connect a line signal to the input. The 500 series standard imposes restrictions on the modules, it concerns the supply voltage, the size of the device and the front panel, etc. In contrast to the solution of many competitors for powering tubes with low anode voltage, we provided the stages with optimal power. This made it possible to unleash the potential of the device and obtain a dense clear sound.