Power Amplifiers

Jones Audio PA-M300 Series 2 Monoblock Power Amplifier

Setup

As you will see from the equipment list posted at the end of this review, my system now uses Stillpoints amplifier stands. The difference in sonic control between these stands and what I was using previously is immense. Placed on the stands, the amps received maximum isolation from external vibrations.

Given that Jones Audio monoblocks sport 20-amp power receptacles, I counted myself extremely fortunate to have on hand 20-amp Nordost Odin power cables. I've tried using adapters to convert 15-amp cords to 20 and vice versa, and I'm convinced that they compromise bass extension, slam, and midrange fullness. Interconnects between my Theta Gen. VIII Series 3 DAC/preamp and the monoblocks were a 1.5meter pair of balanced Nordost Odin. Though I do use audiophile grade fuses in my own equipment, I did not upgrade fuses in the amps.

The amps accept both single-ended and balanced interconnects, and spade as well as banana-terminated speaker cables. Perfect.

The amps had already been broken in prior to arrival. With the rear toggle switch set in "balanced" interconnect position, I first turned on the main power switch on the back of the amps to put them in standby mode. To prevent any possibility of turn-on transients blowing out my loudspeakers, I paused to turn on all my other components (which were already in standby mode). Finally, I turned on the amp's front power switch, located beneath the front of the unit.

Although the amps were capable of playing music immediately, I let them warm up an hour so they would produce optimal sound. Before serious reviewing, I also ran either the Ayre demagnetizing / break-in CD or the more elaborate break-in sequence from Isotek. Finally, I also made sure that all power cables and interconnects were well over an inch apart, as in 2-3" or more.