Case Study:

Updating the System Power Supply
and AC Cabling

The system
  • Wadia 861SE CD player
  • Wadia 170i transport
  • Audio Research Reference 110 power amplifier
  • Nola Viper Reference loudspeakers
What started out as a full-facilities, multi-source system has been simplified and streamlined, using the Wadia CD player’s digital switching facility to control sources and level. That has enabled the owner to dispense with his turntable, phono stage and line stage, allowing the system to be discretely housed in a concealed cabinet. With the construction of the cabinetry in process, the owner took the opportunity to reinvest some of the funds released by the sale of the surplus units in improving the system’s power-supply arrangements.
Existing setup
The electronics will be placed directly on heavy adjustable shelving, allowing plenty of room for ventilation. Previously the system was hooked up using Nordost Valhalla interconnects and Tyr speaker cables, with the supplied generic power cords plugged directly into a basic audiophile extension block.
Structural weaknesses
The electronics are of excellent quality, living proof that just because you don’t have the latest model, you don't have to upgrade. Likewise, the matched interconnects and speaker cables (including the Micro Mono-Filament straps that connect the speakers’ external crossovers) deliver excellent performance. But shifting the system into a cabinet creates both opportunities and potential problems.
  • Using stock AC power cords significantly undermines system performance.
  • There is no separate clean AC ground for the electronics.
  • The use of relatively "massive" shelving in combination with the standard feet fitted to the equipment provides a poor, mechanically resonant support environment.
  • In creating a fixed system installation, it is worth remembering that you may well want to add additional sources (computer audio or A/V) in the future.

The challenge is to at least equal but preferably to better the performance of the system in its conventional, open-rack installation.

Upgrade path
The move to a built-in cabinet creates the opportunity to add a dramatically improved AC supply to the system, as well as dedicated power cords and distribution. The full-height cabinet also allows positional optimization of the system elements. The nature of the changes make individual assessment of impact difficult, but some experimentation was carried out to show benefits.
Step 1
A
dedicated ring-main with its own dedicated fuse board and a medical-grade outlet were installed. A 30A ground wire was used to create a clean earth path to a ground post sunk in the yard, with all cabling concealed behind the storage installation, which runs the entire length of the lounge area in which the system is located. The AC outlets are located in the rear of the system space.
Step 1.1
Shelves were installed in the cabinet as follows: Rather than fixed platforms, the cabinet walls were fitted with 2" x 2" battens, set back to reduce their visual impact. The shelves themselves were constructed from 3/4" plywood, with a layer of 1/2" MDF bonded to the center of the underside, leaving shoulders to rest on the battens. A hardwood trim on the front edge tidied up the appearance as well as further concealed the battens. A substantial gap was left at the rear of each shelf to allow easy cable routing as well as ventilation for the tube amplifier. A total of five shelves were installed.
Step 1.2
The shelves rested on Tip Toes (taken from the previous system installation) to provide better structural isolation between the equipment and cabinet. The equipment was then installed, with the amplifier on the next-to-bottom shelf, the Wadia 171i transport above it and the CD player above that, bringing its controls to a convenient height for operation and leaving a spare shelf above it. The original power cords for the CD player and amplifier were plugged directly into the wall sockets to establish a benchmark of performance.
Sound quality: At this point, the system sounded quite disappointing. A low-frequency thickness created a slow, sluggish sound with poor rhythmic drive and momentum, while the bass had a one-note quality and the midrange was really quite congested and smudged. The removal of the line stage, along with the dedicated rack, had also removed focus and transparency as well as timing and dynamic authority. Clearly there was work to be done.
Step 2
A Quantum QB8 distribution block was installed in the base of the cabinet, connected to the wall outlet with a
Frey 2 power cord. This was placed on the lowest shelf, separate from the electronics, which were now plugged into it. The 30A ground wire was connected to the ground terminal on the distribution block.

Benefits: An immediate improvement in the shape, clarity and focus at low frequencies, which translated directly into greater drive and pace, dynamics and impact in the music. Definition of bass notes still left a lot to be desired, but musical shape, phrasing and flow were all significantly improved, with performances starting to fall into place. Connecting or disconnecting the ground wire produced readily audible improvements in transparency and tonal color, as well as a drop in the system's noise floor.



Step 2.1
Add
Heimdall 2 AC cords between the QB8 and the Wadia 861SE and Audio Research Reference 110 (as well as a Purple Flare Figure 8 power cord for the 171i transport).

Benefits: A natural extension of the improvements delivered by the QB8, the improved power cords added significant shape, definition and texture to the sound right across the range, adding presence and purpose to the sense of musical flow established by the distribution block and grounding. Shifts in musical weight were more dramatic, and bass notes went much deeper.

Step 2.2
Move the speakers forward by around an inch, as well as adjust their level and toe-in.

Benefits: Integration, timing and rhythmic integrity improved, and the soundstage became far more coherent and better defined, with improved depth and a real sense of volume.

Taking stock
The system was now working at least as well as it had originally. The improved authority and dynamics delivered by the distribution block and power cords more than compensated for the loss of the line stage. But the most noticeable change was a new sense of overall coherence, a continuity that affected both the shape and sense of the musical performance and the spatial presentation. However, detail levels were still down and overall clarity could certainly improve.
Step 3
Place three
AC Sort Kones beneath the QB8, Wadia 861SE and Audio Research Reference 110.

Benefits: There was a significant and immediately obvious improvement in the amount of detail, focus and transparency in the system, although at the expense of some tonal thinning. The music was quicker and rhythmically tighter, with more clearly defined space between the players. This was clearly a step in the right direction, but needed further refinement.

Step 3.1
Replace the AC Sort Kones under the QB8 with TC versions.

Benefits: This instantly restored substance and weight to the system but also created a noticeably more natural sense of pace and timing.

Step 3.2
Given the success of the
TC Sort Kones under the QB8, the obvious next step was to place them under the electronics too.

Benefits: Further gains in weight, body, color and dynamic range. The whole sound gained presence and energy, but the positioning of the Kones proved critical. Under the amp, we settled on one Kone (point up) under the mains transformer with the others under the output tubes (point down), while under the Wadia CD player the best positions were point up under the AC input and transport, point down under the DAC board. These variations were quite noticeable, and a little experimentation brought significant improvements in focus, dynamic range and clarity. This is to do with coupling the equipment to the lossy "ground" provided by the constrained-layer shelves, allowing spurious mechanical energy to escape -- a perfect example of Foundation Theory in practice.

Step 3.3
We experimented with adding extra Sort Kones beneath the electronics. The Wadia didn’t seem to benefit, but the addition of two more TC Sort Kones under the Reference 110, sliding first one and then the second beneath the amp until they grounded on the chassis, really worked.

Benefits: A significant drop in the noise floor and grain within the soundstage. Instrumental colors and textures became richer, but the real benefit was in terms of vocals, which became far more natural and believable.

Taking stock
We now had a system that was not only outperforming the original setup in every regard, but one that possessed sufficient resolution and transparency to really show the benefits of other upgrades to its infrastructure.
Step 4
Time to add some QRT to the equation, starting with a
Quantum Qx4 between the QB8 and the wall outlet. This was connected using another Heimdall 2 power cord, leaving the Frey 2 between the Qx4 and the QB8.

Benefits: The Qx4 reduced the noise floor further, revealing greater detail and more space within recordings, but the real benefit was in the way it seemed to deliver a more natural, more believable and more "live" musical performance. The sound stepped away from the speakers, becoming more immediate and much more involving. Using the Frey 2 between the wall and the Qx4 might seem to make more sense, but experimentation showed that we achieved a greater sense of presence and musical purpose with it feeding the QB8. The Qx4 was placed on the shelf next to the 171i.

Step 4.1
Add a pair of
Qv2 Ac Line Harmonizers to the QB8.

Benefits: The Qv2s delivered more color, more space and another increase in the sense of musical flow, bringing out the tube characteristics of the Reference 110, making it an even better foil for the digital precision and detail of the Wadia.

Step 4.2
Add a Qx2 (and another Heimdall 2 power cord) between the QB8 and the Wadia 861SE.

Benefits: This generated greater clarity, transparency and focus, with much crisper and more precise timing and placement of notes. The sense of greater musical organization that comes with each extra element of QRT was obviously apparent, but the Qx2 also seemed to deliver a touch of what can only be described as extra "sweetness" to the sound, a naturalness to both colors and dynamics, making the system far more intimate and expressive. The Qx2 was placed beside the QB8 on the lowest shelf, which made for easier vertical cable dressing.

Step 4.3
All cables were carefully arranged to keep signal and speaker leads away from the power cords, and to ensure that none of the cables touched the walls.

Benefits: Cable dressing can be heard in further drops in the noise floor and a crisper, more "planted" feel of rhythmic security underpinning the music.

Final results
The system transplant has exceeded all expectations, delivering a significant step up in musical performance while also being neater and all but invisible. End result: one happy owner with a very happy wife -- who just wants to know why it couldn’t have been done years earlier, why she had to put up with all that angle iron in her front room, why there were always cables everywhere. Every silver lining has its cloud, but this one dissipated pretty quickly.

Next steps?

The system is currently working so well that upgrade-itis has been well and truly banished. But when that time does come, the obvious path would be as follows:

  • Upgrade the power cords to Frey 2 throughout.
  • Upgrade the interconnects and speaker cables to second-generation, mechanically tuned versions -- including the digital lead between the Wadia 171i and the 861SE.
  • Add a multi-standard A/V source, so that the main system can provide sound for the TV.
  • Look at even more sophisticated solutions for the shelves within the cabinet.

These steps might seem a long way off, but they will in turn deliver even more performance from the high-quality electronics on which the system is based.

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