Pass Labs XP-30 Preamp and Xs Amps

2012-01-24T08:12:17+00:00January 24th, 2012|Home|861 Comments

Pass Laboratories (Pass Labs) has just introduced their new XP-30 preamplifier and all new Xs series of amplifiers. These new products were released at CES 2012 the second week of January and though fall into the category of the uber expensive – we all have the right to dream.

The XP-30 is stated as being Pass Labs highest performing and finest sounding preamplifier, to date. It is a triple-chassis structure with external power supply for two to six amps. Improvements over previous Pass Labs preamplifiers include: less noise, less crosstalk, less distortion and greater dynamic range, resolution, gain, output voltage, and output current. This promises a greater sense of spatiality and dimensionality.

The XP-30 is a modular preamplifier consisting of one power supply and control chassis and additional gain chassis, each serving one channel. It is typically supplied as a two-channel product although it can be configured to serve anywhere from one to six channels, enabling but not requiring the design of very large or unusual speaker systems.

Each channel provides master and slave outputs. A knob on the front of each of the gain chassis sets the slave output to be equal to or less than the master level; all connected gain chassis respond to a master level adjustment on the control chassis. Both single-ended and balanced outputs have the same gain structure and may be used interchangeably. The control chassis also supports a mono function that allows almost limitless multi-amplifier functionality.

The external power supply is large enough for a small power amplifier. Its chassis houses a pair of highly efficient, low-noise Plitron transformers. The circuits use dual mono topologies that supply ample current and excellent voltage stability to the gain stages, as well as inherently better noise suppression and filtering. Very low-noise, high-speed parts further enhance its performance.

The power supply enhancements allow music to flow through the XP-30 with a dramatically greater sense of ease, spatial development and dynamic contrast than through any other of Pass Labs’ preamplifiers.

? Overall Gain: -90 dB to +10 dB -70 dB
? Volume steps: 99
? Remote: Yes
? Inputs: 6
? Outputs: 4
? Frequency Response: -3dB @ 2 Hz and 60 kHz
? Input Impedance: 42k Ohm balanced
? Output Impedance: 120 Ohm balanced, 120 Ohm single-ended
? CMRR: -60 dB, 1 kHz
? Cross-talk: -100 dB, 1kHz Ref 1V
? Signal to Noise Ratio: < -110 dB, Ref 5V
? Power Consumption: 45 watts
? Number of chassis: 3
? Dimensions, Each Chassis: 17″W x 12″D x 4″H
? Shipping Weight (lbs): 75

The XP-30 preamplifier will be available August 2012 for $16,500 U.S.

In addition, Pass Labs has introduced their new generation of audiophile-grade Xs Series amps, starting with the 150-watt Xs-150 and 300-watt Xs-300 mono power amplifiers.

The Xs-300 and Xs-150 Amplifiers are mono block models, both of which offer double-stacked chassis with the power supply and current source in one chassis and the input and main output stage in the other chassis. The separate power supplies enable a bounty of benefits, including lower electromagnetic noise, twice as much storage capacitance as earlier Pass Labs amps, banks of high-speed/soft-recovery rectifiers, improved high-frequency noise filters, bigger and better transformers, improved passive decoupling, massive heat sinks, and lower standby currents.

The Xs Series has been three years in development. The first year, Pass Labs settled on the power supply and physical package. The second year, Pass Labs finalized the output stage and front end. The third year, the company refined the front end and the biasing of the output stage.

In the process, Pass Labs applied a number of new refinements, including adjusting the values for push-pull Class A biasing and the amount of single-ended bias in the output stage. It also significantly increased the single-ended bias in the output stage over earlier Pass Labs amplifiers. All three changes delivered major improvements. Pass Labs also installed sturdy output stage transistors; with a combined capacity well over 10 KW, and massive heat sink assemblies capable of 2 KW all day long.

? Separate chassis for lower electromagnetic noise
? Power supplies with greatly enhanced storage capacitance
? Banks of redundantly parallel high speed / soft recovery rectifiers
? Improved high frequency noise filters
? Larger / quieter transformers
? Improved passive decoupling
? Lower power standby
? Input impedances of 200 k-ohm balanced with negligible capacitance

The new Xs-150 and Xs-300 will be available in Q1 2012 at a price of $65,000 U.S. and $85,000 U.S. / pair respectively.

Look for more information on these products at:

  • About the Author:

    Leave A Comment