Audibax PP4000 - phono preamps. Most audio devices can only process line level signals. The level of signals from a turntable is very low. Therefore, the phono preamp Audibax PP4000 must always be used. With Audibax PP4000, it is an interface for the turntable that modifies the signal to be able to use with the various devices such as mixer, audio amplifier, mini chains, recorders, external sound cards, etc. The Audibax PP4000 is a compact preamp that adjusts the low-level output signal of a turntable to the RIAA standard. Both the phono input and the line output are done via a stereo RCA port. It also has a grounding port so your turntable has no induced interference. The 6.35 stereo jack allows you to connect headphones and monitor the already converted signal. The Audibax works with the included 12 volt power supply and has a power indicator LED at the top. Audibax PP4000 has a feature that stands out from the other RIAA preamps. It is the on/off switch. In most markets, you need to disconnect the power supply.