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Reviewer: Steve Marsh
Financial Interests: click here
Digital Source: Vecteur D-2 CD Transport, Audio Note DAC Kit 1.2 with upgrades (ps choke, tantalum resistors, Black Gate caps, copper grounding bars on digital chips wired to central ground, VTV silver foil/oil output coupling caps)
Analog Source: Nottingham Analogue Mentor turntable with 10” Ace Anna tonearm, Benz LP-S moving coil cartridge
Preamps: Doshi Alaap Purist Mk. II full-function tube preamp, Cello Audio Suite
Power Amps: Tron 211 SET amp with upgraded exotic-core interstage transformers (General Electric 211 power tubes, Western Electric 417A/5842 input tubes, RCA black plate 5U4GB rectifiers), Cello Performance amps
Speakers: WLM LaScala floorstanders
Interconnect cables: Music Metre Fidelis digital, Harmony Audio, Acoustic Systems Liveline, Bastanis Epilog I
Power Cords: Bastanis Epilog II on Tron amp, industrial-sourced power cord on Doshi preamp, Shunyata Taipan Helix Alpha cords on transport and DAC
Speaker Cables: Bastanis Epilog Mk. II, Acoustic Systems Liveline
Equipment Rack: Adona 6-shelf, low profile isolation rack
Power Line Conditioning: PS Audio P300, Nordost QRT power purification system [on review]
Sundry accessories: Audio Prism Ground Control, Stein Harmonizers, Stein Magic Stones, Isoclean Fuses, VPI 16.5 record cleaning machine
Room Size:  29’ long X 16’ wide X 10’ high (sunken living room with open floor plan, listening across width of room)
Review Component Retail Prices: QBase 4 $849.99; QBase 8 $1399.99;
Qx4 $2699.99; Qx2 $1799.99; Qv2 $350; power cords/1m - Blue Heaven $199, Heimdall 2 $599, Frey 2 $1599

The Nordost QRT system first caught my ear at the 2011 Rocky Mountain Audio Fest. Nordost is known for conducting excellent show demonstrations of their products and this was no exception. As each part of the QRT system was incrementally added to the system, the improvements were easily audible, taking a visitor’s Black Crowes CD cut from pinched and nasal to smooth and open. The difference was really quite dramatic. At the end of this demo I approached Nordost rep Paul Ritchotte with an interest in a review. It took a while to get things rolling due to the upcoming CES and a company move but Paul personally delivered the products to my home and spent the better part of a day installing them as I listened step by step.

The major design philosophy of the Nordost power purification approach is that, while their products address EMI, RFI and other AC line noise, they do not use conventional filtering or power regeneration technology. As a result the QRT system does not limit peak current or alter source impedance, both of which can reduce system dynamics. While the reduction of a system’s dynamics has been a common complaint about AC conditioning products in the past, the industry has largely moved beyond this issue and developed highly innovative products some of which actually increase dynamics.

The Nordost power purification system is not a one-box solution as is the case for most power conditioners on the market (Audience, Shunyata, PS Audio, Silver Circle etc.). Rather there is a sequential approach to installing diverse QRT products in your system. The foundation is the QBase. If you only bought one product from the QRT line, this is what they recommend. While it may look like nothing more than a nicely finished power strip, it was carefully designed to offer the following features (excerpted from the Nordost literature): straight-line low loss design maintains low source impedance of AC supply; focused star grounding; external ground post for connection to separate clean ground (which I was unable to utilize); mechanically tuned casework made of extruded aluminum with machined end caps; internal PCB deliberately preferred here over hard-wiring.

The AC conditioning status of my own system has languished for a number of years. I have been steadfastly clinging to my almost vintage PS Audio P300 with multiwave upgrade. I have not experimented with many of the current crop of AC conditioning units (Shunyata, Audience etc.) but did get a chance to try the PS Audio Power Plant Premier. While I heard improvement in some areas, I preferred the P300 overall. Oddly the Premier seemed to negatively affect midrange tonality. This was particularly noticeable on vocals. I have experimented some with power cords and been using the excellent Bastanis Epilog on my Tron 211 SET amp and Cello Performance amps. Both my Vecteur transport and Audio Note DAC responded well to substituting a modest Shunyata Taipan Helix Alpha, smoothing out some of the hardness of the stock cord.

While I tried a Bastanis Epilog power cord and another Shunyata on the power supply of my Doshi preamp, I actually preferred a power cord sourced from a very expensive retired commercial communications component. The power cord on my Nottingham Analogue Mentor turntable is captive. In the power conditioner arena all would agree that lowering of the noise floor and concurrently the residual electronic haze between instruments in the soundstage is the minimum benefit expected. Power conditioners today must distinguish themselves beyond this with detail retrieval, soundstaging, tonal balance, dynamics and harmonic structure.

Delivery and setup. Paul Ritchotte brought the following QRT components for my review: QBase 8 (eight outlet power strip); Qx2 + Qx4 power purifiers;  4 x Qv2 line harmonizers; and Blue Heaven, Heimdall 2 and Frey 2 power cords. As Paul sequentially installed each into my system, I was able to hear the sonic effects of each and would comment on them to Paul. Even so it was obvious that I’d have to remove everything after he left and painstakingly insert each component one at a time and do critical listening after each change. So that’s where I began.

Placing the QRT components on an equipment rack shelf helps performance according to Nordost but I just did not have the room. The Qx components were placed on my wool carpet under my Adona rack and the QBase ended up on the bare hardwood floor behind the rack. Later I slid ceramic tiles under the Qx units to provide a more rigid support than the carpet.