Pass Labs X1000 monoblock power amplifier Associated Equipment
I drove the X1000s with a variety of front-ends. This included running direct from the analog outputs of the dCS 972 Sample Rate Converter and Elgar D/A processor at 24/192, and from the balanced outputs of the fully differential BAT VK-5i/VK-P10 preamp/phono combo. (The X1000 manual is quite explicit that the output impedance of the associated preamp is of little consequence, and that balanced is better.) I also used the new Classé Omega line-level preamp, from both its balanced and single-ended outputs. I got fabulous sound with the single-ended Nagra PL-P preamp, but only when using the special RCA-to-XLR Canorus Cable supplied by importer Steve Lee.
Because of the electrically floating output of the Elgar and the floating input of the big Pass amps, neutral and ground had to be tied together on the interconnect to avoid nasty clicks and pops. (For best results, always use a "switcher" interconnect rather than an RCA-to-XLR adapter.) Analog was supplied by the Forsell Air Force One/vdH Black Beauty combo.
Loudspeakers were JMlab Utopias. Speaker cables and interconnects were largely Synergistic Research Designer's Reference with the Discrete Shielding upgrade, along with their terrific new Reference Squared Master Couplers. XLO The Limited, Cardas Golden Reference, and TARA The One also saw service. A truly astounding improvement was also effected by an API Power Wedge Ultra 116 on the front-end, and a pair of Ultra Enhancers on the amps. These latter guys are not leaving my system anytime in the foreseeable or way-far-distant future; hugely and vociferously recommended.—Jonathan Scull