NAGRA BPS Bipolar Transistor Phono Stage
This tiny, lightweight, battery-powered jewel is loosely based on Nagra's VPS phono stage & uses bipolar transistors instead of tubes. The bottom of the company's familiar brushed-aluminum case has a grippy rubber material die-cut to spell Nagra. It's intended to keep the preamp from sliding, but stiff cables will have the BPS hanging in the air if you're not careful. The BPS costs $2399.
The BPS provides a highish 51dB gain in moving-magnet mode and 62dB in moving-coil, which should suffice for all phono cartridges, other than those of the very lowest output. The MC circuit uses the same excellent custom-wound transformers found in the more expensive VPS. The BPS doesn't consume much power—its single 9V battery should provide about 100 hours of use before it needs replacing. The On/Off switch includes a battery-test position, but unfortunately my pea brain had me forgetting to turn the BPS off many times—I went through quite a few batteries. The BPS also has a jack for a power adapter—not for listening, but to keep the circuit "busy" and warmed up when you're not listening.
Internal jumpers let you set MM or MC, and balanced or unbalanced operation. The BPS comes from the factory already set for unbalanced operation, which Nagra suggests you leave unchanged unless you encounter hum. The MM default setting is 47k ohms loading at 150pF capacitance. Supplied plug-in modules let you switch between capacitive and resistive loading, depending on whether your cartridge is MM or MC. The resistive loading modules are 100, 200, 300, 500, and 1000 ohms.
So gang, this piece has proven to be the quitest, most engaging phono preamp I've/we've ever experienced. It's extraordinary, as every piece of NAGRA gear is. We've tried it with a Van den Hull "One" MC Cart and it's the quietest, most resolving phono cart/preamp combo ever played in this shop. This battery powered mini mite is truly high-end and is to be used in a true refernce setup. Basically a halo piece and one any vinyl lover should have on their list of phono preamps to try… then own.
Come give this fine NAGRA a twirl here at the Lawrence shop or purchase with confidence via this site.
NAGRA BPS Bipolar Transistor Phono Stage: $1699 plus tax when applicable