"Amplifiers – pure and simple"
Some 35 miles northeast of Sacramento, California, lies Pass Laboratories. From here, come some of the best amplifiers the world has ever heard.
About the XP-12
The new XP-12 starts with a new power supply. It uses an efficient toroidal design with both an electrostatic and Mu metal shield along with vacuum impregnating and epoxy fill. This gives us a very quiet transformer both electrically and mechanically. The power supply circuitry itself is also lower noise and has additional filtering; According to Pass this is a little more complicated but worth it.
The XP-12 uses the single stage volume control borrowed from the XS line preamp. This gives one hundred 1 dB, steps with lower noise and distortion while removing some signal path parts.
The gain circuitry continues to use our favorite transistors from Toshiba but has a larger, higher biased output stage similar to the XS preamplifier auto bias. This makes longer and multiple cable runs easier to drive and gives us the advantage of simplifying our single ended output circuitry while increasing performance. Overall this makes for a quieter more neutral, musical and versatile control center for your system.
Tech Insight
The heart of this preamp are the Pass-favoured Toshiba Jfets used as gain devices in a clever balanced design. The volume (100 x 1dB steps) is executed via a microprocessor-controlled optical shaft encoder connected to the large knob on the XP-12’s front. Interestingly though, the attenuation itself happens by using an integrated op-amp/volume control ic (the Muse 72320), but in this case, only employing the resistor ladder sections.
Specifications
Overall Gain9.3dB Balanced
Inputs 5
Outputs 2
Input Impedance 22K Ohms
Power Consumption 30 watts
Dimensions 17”W x 12”D x 4”H
Weight 20lbs
Matching & Setup
As with any preamp, it's the control centre of your system and the 'signal centre' too. So proper setup with supports and cabling is important to preserve the integrity of your precious music signals. The quality of power supplies in Pass equipment means that inherent noise is low, and with the classic purity of their class A gain stages, means they are very transparent. The upshot of this is that experimenting with supports in particular can bring lots of extra resolution and fine detail.
Connectivity options are of course all analogue RCA and balanced. And whilst this pre is a natural match for something like the XA30.8 stereo power amp (which we also have on permanent demo), it has good line driving capability and so makes a great pre to drive long interconnects feeding active speakers.