Phono Preamp Liberty Audio B2B-4: “double mono” on field effect transistors

Engineers of the American company Liberty Audio approached the “double mono” layout very simply: in the case of the B2B-4 phono corrector, two identical boards of monophonic amplifiers were installed, supplemented by the RIAA curve conversion scheme, which is observed with an accuracy of 0.1%.

The amplifiers are assembled on field-effect transistors — so it was possible to minimize noise and achieve another parameter, which the manufacturer noted separately. The rise rate of the B2B-4 signal is 300 ns, which is about twice as good as that of its analogues. This significantly improved the sound of the new product.

The B2B-4 consumes 50 watts from the mains. The excess energy is dissipated by the lower panel of the phono corrector housing — an aluminum plate with a thickness of 10 mm.

To further reduce noise and interference, the power supply unit is placed in a separate module, in which a massive toroidal transformer is installed. Power from separate secondary windings and, accordingly, stabilizers, is transmitted via a multi-core cable to a special connector. Both modules, which make up the B2B-4, are assembled in massive metal cases with a black coating.

In the US, the Liberty Audio B2B-4 phono corrector will cost $4,500.