Upgrade AudioQuest Level-X DBS Packs For Older Sky ICs And Everest Speaker Cables

DarqueKnight
DarqueKnight Posts: 6,765
edited February 2023 in 2 Channel Audio
Introduction

I wondered if the latest AudioQuest Level-X DBS packs would improve the performance of my older AudioQuest Sky Gen2 (2008) and Sky Gen3 (2011) XLR interconnects. They did. The Level-X packs are sold individually and retail for $140 each/$280 a pair.

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Figure 1. Sky Gen2 XLR interconnects. The jacket braid pattern has long blue stripes.

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Figure 2. Sky Gen3 XLR interconnects. The jacket braid pattern has long black stripes.

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Figure 3. Internally, Sky Gen3 has a 5 layer noise dissipation system. Sky Gen 2 has a 3 layer noise dissipation system.

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Figure 4. Left to right: Sky Gen2 DBS pack, Sky Gen3 DBS pack, DBS Level-X pack. Level-X packs have a RF noise trap.

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Figure 5. Level-X packs use smaller 27A alkaline batteries (left). The older DBS packs use 23A alkaline batteries.

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Figure 6. Level-X packs house the six 12V batteries in a caddy, unlike previous DBS packs where the batteries just slipped into the battery pack case. I had to call AudioQuest and ask how the bottom end cap was removed. You grip the case rear (where the straps are) with four fingers and use your thumb to flip up the case bottom from the front.

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Figure 7. The battery caddy is held in place by an "L" shaped latch that must be gently pried away from the caddy bottom, and then gently pried away from the batteries. I used a small jeweler's screwdriver. I can see this being a liability for breakage.

Listening Evaluations

Mono and stereo music was used. In mono mode, listening was done at the listening seat and taking turns standing 1 foot in front of each speaker with my left ear in the center of the driver and tweeter arrays.

The Sky Gen2 XLR cables were listened to with the Sky Gen2 DBS pack on the right output of the DAC and the left cable compared with no DBS pack, the Gen2 DBS pack, the Gen3 DBS pack, then the Level-X DBS pack. Next, the Sky Gen2 XLR cable with Level-X DBS pack on the right and Gen3 cable on the left with no DBS pack was compared. Finally, The Sky Gen3 XLR cables were listened to with the Gen3 DBS pack on the right output of the DAC and the left output cable compared with no DBS pack, the Gen2 DBS pack, the Gen3 DBS pack, then the Level-X DBS pack.

With the Sky Gen2 cables, the side with no DBS pack had diminished clarity and detail. The Gen3 and Level-X DBS packs provided increasing, but small improvements in clarity and detail. The Gen3 cable with no DBS pack had much higher clarity and detail than the Sky Gen2 cable with the Level-X DBS pack.

Sonny Rollins' "Blue 7" from the "Saxophone Colossus" SACD (mono recording) was used extensively in listening sessions. Beginning at 8:11 and continuing to 9:22 there is a double bass solo with the drum player using brush work on the cymbals in the background. The bass string overtones and the wood body of the bass become more sharply defined with the progression from no DBS, to Gen2, to Gen3, to Level-X. Similarly, on the same recording, the strikes on the high hat from 7:15 to 8:10 had more more metallic overtones, clarity, and detail with the progression from no DBS, to Gen2, to Gen3, to Level-X. There were also small improvements in bass definition, articulation, and weight.

When listening to stereo music, there was a little more image weight, more sense of space around images, and blacker background. There was no change in sound stage dimensions. In both mono and stereo modes, the side with the Level-X pack was apparently louder.

Measurements

Frequency spectrum (Fast Fourier Transform) measurements were taken from the output of the left XLR output cable of the DAC. A Tektronix TDS 2012 digital oscilloscope was used. A 60 Hz sinusoidal test tone from the Autosound 2000 Low Frequency Test CD was used. The horizontal axis is in increments of 10 Hz. The vertical axis is in increments of 2 dB. Results from the eight FFT plots are summarized in table 1.

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Figure 8. FFT plot of 60 Hz test signal at output of Sky Gen2 cable with no DBS pack.

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Figure 9. FFT plot of 60 Hz test signal at output of Sky Gen2 cable with Gen2 DBS pack.

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Figure 10. FFT plot of 60 Hz test signal at output of Sky Gen2 cable with Gen3 DBS pack.

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Figure 11. FFT plot of 60 Hz test signal at output of Sky Gen2 cable with Level-X DBS pack.

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Figure 12. FFT plot of 60 Hz test signal at output of Sky Gen3 cable with no DBS pack. The second harmonic at 120 Hz is significantly reduced.

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Figure 13. FFT plot of 60 Hz test signal at output of Sky Gen3 cable with Sky Gen2 DBS pack.

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Figure 14. FFT plot of 60 Hz test signal at output of Sky Gen3 cable with Gen3 DBS pack.

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Figure 15. FFT plot of 60 Hz test signal at output of Sky Gen3 cable with Level-X DBS pack.

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Curiosity Killed The Cat - But Satisfaction Brought Him Back

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Figure 16. The "pigtail" 3.5mm plug for my AudioQuest Everest speaker cables had a bulbous housing that did not allow the metal plug to fit into the Level-X DBS pack jack. I say "had" because I Dremeled it down to fit.

The Level-X DBS packs were a relatively inexpensive upgrade that produced Such Good Sound that I became curious about what they could do for my Everest speaker cables. An AudioQuest technician said that I could send the Everest cables to be refitted with modern pigtails, or, I could save some money and trim the plugs of the pigtails. A sturdy bench vise, of which I have several, is essential for holding such delicate trim work.

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Figure 17. The Sky and Everest plugs were both 28 mm long with a metal tip length of 11 mm. The Sky plugs were 6.55 mm at their widest compared to 6.71 mm for the Everest plugs.

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Figure 18. The Everest plugs were trimmed down to 6.33 mm.
Proud and loyal citizen of the Digital Domain and Solid State Country!

Comments

  • DarqueKnight
    DarqueKnight Posts: 6,765
    edited February 2023
    Using the same 60 Hz test signal and listening methods as with the Sky XLR interconnects, the Everest speaker cables were listened to and measured with no DBS pack, their original DBS pack, a Sky Gen3 DBS pack, and a Level-X DBS pack. The differences among the DBS packs were smaller than with the Sky interconnects, but this reflects substantial noise abatement upstream. For example, the Pass Labs X600.5 monoblock amplifiers have significant RF filtering. From the owner's manual:

    "The AC power input to the amplifier runs through a RF filter, which removes high frequency noise coming into and going out of the amplifier power supply.

    Listening in mono mode and keeping original Everest DBS pack on the left while progressing from no DBS pack on the right, to the original DBS pack on the right, to the Sky Gen3 DBS pack on the right, to the Level-X DBS pack on the right did not produce a pronounced shift in sound quality toward the better DBS pack side. Clarity and detail, particularly in the bass region, improved in the center.

    The 120 Hz second harmonic seen in the FFT plots at the output of the Sky interconnect was totally suppressed at the output of the right Everest cable. There were two prominent noise artifacts between 120 Hz and 130 Hz until the Level-X pack was installed. After which there was only one prominent noise artifact between 120 Hz and 130 Hz. The background noise density in that area was also lower.

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    Figure 19. FFT plot taken at output of Everest speaker cable with no DBS pack attached.

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    Figure 20. FFT plot taken at output of Everest speaker cable with original DBS pack attached.

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    Figure 21. FFT plot taken at output of Everest speaker cable with Sky Gen3 DBS pack attached.

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    Figure 22. FFT plot taken at output of Everest speaker cable with Level-X DBS pack attached.

    In the future, when I am more dedicated to audio than I am now, I will retire my ancient DBS cables for more modern and higher performing models.

    Reference:

    How Long My AudioQuest DBS Batteries Lasted
    https://forum.polkaudio.com/discussion/197741/how-long-my-audioquest-dbs-batteries-lasted

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