Revelation Audio Labs Passage CryoSilver Reference DB25 Power Cable

DarqueKnightDarqueKnight Posts: 6,539
edited August 2014 in Electronics
Introduction

I have sometimes wondered if the ordinary DB25 cables which connect the power supply and control chassis of my Pass Labs XP-25 phono preamp and XP-30 line level preamp were compromising performance. I recently found out that they were. A forum member (and Pass Labs XP-20 preamp owner) mentioned that he had achieved improved performance by replacing the stock DB25 with a Passage Cryo-Silver Reference umbilical power cable made by Revelation Audio Labs (Thanks Bluefox).

I asked Pass Labs if they had experimented with different DB25 cables. This was their response:

"We played with a few different DB25 cables but never noticed much of a difference. The only signals that travel over those cables are DC voltages and logic signals for the relays. I don't remember trying the cables you are looking at so who knows they may make a difference. This is audio and the only way to know for sure it to listen."

I was also curious about specific pin assignments and if all twenty-five pins were used. Here is the response and pin assignment chart I received:

"Here are the specific pins. Multiple Grounds + 8-10 volts for digital power and then left and right analog unregulated at about 40 volts. Pins 12 and 13 are shown jumpered as this is a PCB view. These are separate wires in the cable used for a loop back sense function to keep power off until both units are connected."


011PassLabsDB_25Pins_zpsee30dec4.jpg
Figure 1. Pass Labs DB25 pin assignments for XP series preamps.

Construction Features

Deep cryogenic treated oxygen-free 99.999% (5n) ultra-pure solid core silver conductors. Each conductor hermetically sealed within its own oversized 100% pure virgin Teflon (PTFE) hollow air tube. Mil Spec Amphenol male-to-female DB-25 connectors and solid cast metal shielded shells. Multiple layers of heavy shielding, comprised of multiple layers of 5 mil solid copper, and Mil-Spec helical woven silver-plated stranded copper braid. Ceramic Micro-Spheres in cable conduit for micro-vibration abatement. Pre-conditioning on an Audiodharma Cable Cooker for 60 hours.

Price: $599 for 0.75 meter, $100 for each additional meter, 30-day audition with 20% restocking fee or 100% exchange credit, limited lifetime warranty.

I required three 1 meter cables, one for the XP-25 phono preamp and two for the XP-30 preamp. My cables arrived exactly three weeks after placing the order. They arrived in a well-padded box and were enclosed in a heavy velvet bag, with cable ends wrapped in bubble wrap. My pre-order and subsequent questions were always answered within 24 hours and most often within a matter of hours.

014RALVelvetBag-s_zps1e22396b.jpg
Figure 2. Fond of purple: RAL cable packaging.

012RALDB25BentPins-s_zps5e40e171.jpg
Figure 3. Misaligned pins of one cable end.

The pins of one of the cables were misaligned, probably due to bumping in shipment. They were gently pushed back into alignment with a small flat blade screwdriver. I suggested that the manufacturer use some type of plastic cap over the cable ends. The suggestion was well received. I purchased some DB25 end caps for 30 cents each.

Quantitative Analysis

The XP-30 is my third Pass line stage preamplifier. I went from the X1 to the X0.2 to the XP-30. I still have the short thicker DB25 cables that came with my X0.2, which had to be replaced with longer cables. I was curious if there was any measurable noise performance difference among the X0.2, XP-30, and RAL DB25 cables and there was.

017RAL-XP30-DB25Cables-s_zpsb29b0ece.jpg
Figure 4. RAL DB25 and stock XP-25/XP-30 DB25 cables.

018XP-30-X0_2-DB25Cables-s_zpse5c8f19c.jpg
Figure 5. Stock X0.2 DB25 (bottom) and stock XP-25/XP-30 DB25 cables.

I made attachment fixtures from a spare DB25 cable in order to connect the cables to my Audiodharma Cable Cooker and use the Cooker's output signal as a test signal. Figures 7-9 show the results. All of the DB25 cables showed considerable ringing noise, but the RAL cable showed the smoothest and lowest amplitude ringing noise.

000CookerSignal-s_zps17c1402f.jpg
Figure 6. Cable Cooker output signal.

002XP-30DB25Pk-Pk-s_zps02b838df.jpg
Figure 7. Cable Cooker output signal through the stock XP-25/Xp-30 DB25 cable.

001X0_2DB25Pk-Pk-s_zpsc2bc4c47.jpg
Figure 8. Cable Cooker output signal through the stock X0.2 DB25 cable.

003RALDB25Pk-Pk-s_zps7c2af39c.jpg
Figure 9. Cable Cooker output signal through the RAL Passage DB25 cable.

Installation Mission Impossible

The RAL DB25 cables are thick and stiff. I did not want to pull my 9,957 pound equipment cabinet from the wall, and I did not want to move my perfectly set up turntable and SACD player out of the way. That meant I had to lean over the cabinet from the center and work within the 5-3/8" space between the cabinet and the wall. That wasn't so difficult when working with the XP-30's connectors, since all the chassis were in a stack in the center of the cabinet. The XP-25's chassis were under the turntable and SACD player, therefore I had to contort a bit and lean over at an angle, all the while being careful not to bump anything. I tacked a hand mirror to the wall behind each Pass component's DB25 jacks and I used a headband LED light too see what I was doing. Things were further complicated by the tiny slot-head screws on the RAL connectors. The cables put up a good fight like a baby python, but I won.

005AudioSystemCabinet_zpsd473f360.jpg
Figure 10. Fond memories of wrestling my RAL DB25 cables into their new home.

009Energizer4LEDHeadband-s_zpsab46411e.jpg
Figure 11. My LED headband light was an indispensable tool.

010MirrorImageDB25-s_zpsc6213812.jpg
Figure 12. Part one of mission impossible completed! Five more to go.

The 1 meter length was just long enough to allow a comfortable bend radius of 5 inches at each end and a little bit of slack in the cable. In hindsight, a 1.25 meter length would have been easier to handle. I could have exchanged the cable for a longer length if I wanted. Foam blocks were placed under each connector for strain relief.
"So hot it burns Mice!"~DK
"Polk SDA-SRSs are hopelessly out of date both sonically and technologically... I see no value whatsoever in older SDA speakers."~Audio Asylum Member
"Knowledge, without understanding, is a path to failure."~DK
"Those who irrationally rail against something or someone that is no threat to them, actually desire (or desire to be like) the thing or person they are railing against."~DK
Post edited by DarqueKnight on

Comments

  • DarqueKnightDarqueKnight Posts: 6,539
    edited July 2014
    Listening Tests

    High quality stereo and mono recordings in CD, SACD, and LP formats were used in evaluations. LPs had been steam cleaned, then wet cleaned with a VPI 16.5 record cleaning machine, then stored in Mobile Fidelity anti-static record sleeves.

    RAL recommends a break in time of 250 hours and that critical listening not be done until after the 250 hour break in period. I prefer to begin critical listening immediately and document sonic changes during the break in process. RAL preconditions their cables for 60 hours on an Audiodharma Cable Cooker. The Cable Cooker's manufacturer stated that one hour on the Cooker is roughly equivalent to three hours of playing time, therefore I needed to go another 70 hours to meet RAL's specification. However, I typically continue the break in process until I reach a 48 hour period with no sonic changes. My evaluation process spanned 150 hours, with no changes discerned after the listening session at the 96 hour point.

    An RAL DB25 cable was first installed on the XP-25 phono preamp. Listening notes and sound stage image charts were first made with the stock DB25, then with the RAL DB25. Figure 13 shows the lateral sound stage chart for the 180 gram vinyl version of "Take Five" from Dave Brubeck's "Time Out" album. Before I listened to any music, I heard an improvement in one performance aspect. The close proximity of the XP-25's control chassis to an X600.5 power amplifier induces a faint hum. That hum appeared to be reduced by approximately half after the RAL DB25 cable was installed. There wouldn't be any hum at all if I placed the XP-25's control chassis on top of my equipment cabinet between the turntable and SACD player, but that option is not aesthetically pleasing.

    016RALDB25-Vinyl-7-5-14-s_zps5b0942da.jpg
    Figure 13. Lateral sound stage chart for "Take Five" 180 gram vinyl version. The +/- numbers indicate
    in feet how far ahead or behind the speaker plane a sound image was localized.


    Some of the differences immediately heard with the RAL DB25 cable were:

    1. More rumble and growl texture to bass notes.
    2. More tactile sensation from acoustic bass and low piano notes.
    3. More image weight, definition and solidity.
    4. More bass weight, articulation, and clarity.
    5. More overall clarity.
    6. Music sounded apparently (but not measurably louder) louder due to lower noise floor.
    7. Larger and more defined ambient sounds.

    I usually go back and forth several times between an old and new cable, but I only "fell back" once in this case because

    1. The differences were so striking.
    2. My mind could not come to terms with bending over and reaching behind my equipment cabinet multiple times and dealing with the baby python, even though handling was easier the second time around because the cable had been bent into shape.

    Going back to the stock DB25 took away the increased image weight, enhanced ambient sounds, additional detail, and bass enhancements. The XP-25's RAL DB25 was reinstalled, permanently, and an RAL DB25 was then installed between the XP-30's control chassis and the right channel amplification chassis. There was an increase in image weight and apparent loudness on the right.

    Next, leaving the RAL DB25 only on the right, I switched to the SACD version of "Take Five" and was bitterly disappointed. I was shocked that Such Good Sound had disappeared like a thief in the night. The right side still sounded louder, but lacked in detail and clarity compared to the (stock) left side. There was also a shift of the center image to the left. In other words, the analog source sounded better on the right whereas the digital source sounded worse. I first thought the RAL cables were "overcooked", but I realized that, if that were the case, things would have sounded bad with the analog source too. I assumed that there was some electronic "imbalance" the SACD player was sensitive to and that the situation would improve by installing the XP-30's left side RAL cable. The sound did improve for the turntable, but it became much worse for the SACD player, as shown in figure 14. With both RAL DB25 cables on the XP-30, the sound stage almost collapsed when listening to the SACD player, yet the turntable was exhibiting a new fullness of life.

    015RALDB25-SACD-7-5-14-s_zps23b214d6.jpg
    Figure 14. Lateral sound stage chart for "Take Five" SACD version. The +/- numbers indicate
    in feet how far ahead or behind the speaker plane a sound image was localized.


    The sonic aberrations I was hearing with the SACD player were just like the ones I had heard previously when I had overcooked cables. However, I don't recall a case where things sounded "overcooked" with one source and sounded great with another. After 36 hours, the SACD player was back to normal, but not improved sound. With the SACD player, I began hearing some of the improvements heard on the analog side after the 36 hour mark.

    At the 72 hour mark, I did an A/B comparison of the vinyl and SACD versions of "Take Five" by pausing the SACD version on one of the initial beats, starting the record version and restarting the SACD version when the record caught up. The image sizes, image placement, and overall sound level were identical. The record had more bass weight, bass detail, and bass articulation. There was also a bit of sibilance on the cymbals and some saxophone notes.

    At the 96 hour mark, the sibilance was gone. At this A/B comparison of the vinyl and SACD versions of "Take Five", the SACD had more bass weight, bass detail and articulation. The SACD also had more high frequency detail and better ambient information presentation. Cymbals had more shimmer, decay, and detail.

    I did not hear further changes, on any recordings, at the 120 hour and 150 hour listening sessions.

    004AudioSystemAngle_zps4d3fc0a0.jpg
    Figure 15. Two channel system listening room. I often use Dave Brubeck's "Time Out" album for equipment
    evaluations because of the recording clarity, life size (on my system) images, and sound stage width. The
    drum set is placed on the left, in front of and extending leftward of the left speaker. The saxophone is in the
    center and projected forward of the speaker plane. The acoustic bass is just to the left of the right speaker.
    The piano extends from the right speaker to behind the chair at the right.


    Referring to figure 15, on Sheila E's "Writes of Passage" CD, there is an intro track called "TrainAComin'", which is the sound of a train moving from left to right. Normally, I hear the train begin at the left wall, move to the right just under the tops of the speakers, and end at the archway door. During the "crushed sound stage" episode, the train began in the middle of the left speaker, moved to the right along the top of the equipment cabinet, and stopped at the middle of the right speaker.
    "So hot it burns Mice!"~DK
    "Polk SDA-SRSs are hopelessly out of date both sonically and technologically... I see no value whatsoever in older SDA speakers."~Audio Asylum Member
    "Knowledge, without understanding, is a path to failure."~DK
    "Those who irrationally rail against something or someone that is no threat to them, actually desire (or desire to be like) the thing or person they are railing against."~DK
  • DarqueKnightDarqueKnight Posts: 6,539
    edited July 2014
    Prior XP-30 and XP-25 Tweaks

    The following prior tweaks were performed on both the XP-30 and XP-25:

    1. Chassis lined with Dynamat Xtreme vibration abatement foil.
    2. Stock power line fuse replaced with a HiFi Tuning Supreme audio grade fuse.
    3. Stock power cord replaced with a PS Audio AC 12 power cord.

    The RAL Passage Cryo DB25 power cords provided the most significant sonic improvement of any tweak to date. The price of the RAL cords was very reasonable considering their quality and performance and considering their prices were only 6.6% and 8.5% of retail prices of the XP-25 and XP-30 preamps.

    Power infrastructure Summary

    Stable and clean AC power is the foundation of good stereo sound. My two channel stereo system is fed by three dedicated 20 amp AC circuits, each terminated with a PS Audio Soloist Premier SE passive in-wall power conditioner and a QuietLine high frequency noise filter. Each component is fed by a PS Audio AC-12 power cord. The power amplifiers are plugged into the Soloists. The source components are plugged into a PS Audio P10 AC regenerator. All fused components, except for the turntable motor power supply, had the stock fuses replaced with audio grade HiFi Tuning Supreme fuses. The turntable motor power supply has a HiFi Tuning Gold fuse. I did not hear or measure a performance difference between the Gold and Supreme fuses in that application. The source components receive additional power filtration and mechanical noise abatement from a PS Audio PowerBase.

    Further Study

    It is fascinating how this cable upgrade provided an immediate and continual improvement to a pure analog signal, but the reconstituted analog signal from a digital source was initially severely compromised. In the future, when I am more dedicated to audio than I am now, I will seek scientific answers to this mystery.

    References

    Two Channel Audio System Equipment List And Photos

    Revelation Audio Passage CryoSilver Reference DB-25-Power Cable Review - (Martin T) Art of Sound Forum

    Revelation Audio Passage CryoSilver Reference DB-25 Power Cable For Pass XP-20 Preamp Review - (Bluefox) Polk Audio Forum

    Pass Labs XP-30 Line Level Preamplifier Review

    Pass Labs XP-25 Phono Stage Review

    PS Audio PerfectWave AC-12 Power Cord Review

    Vibration Abatement For The Pass Labs X600.5 Power Amp and XP-30 And XP-25 Preamps

    A Comparison Of The SACD, CD, and LP Versions Of Six Titles
    "So hot it burns Mice!"~DK
    "Polk SDA-SRSs are hopelessly out of date both sonically and technologically... I see no value whatsoever in older SDA speakers."~Audio Asylum Member
    "Knowledge, without understanding, is a path to failure."~DK
    "Those who irrationally rail against something or someone that is no threat to them, actually desire (or desire to be like) the thing or person they are railing against."~DK
  • ThortonThorton Posts: 1,240
    edited July 2014
    005AudioSystemCabinet_zpsd473f360.jpg


    DK, that is beautiful!
    _____________________________________________________________________________________________
    Source: Roon via ethernet to DAC interface
    DAC: Bricasti M1SE
    Pre/Pro: Marantz AV8805
    Tube Preamp Buffer: Tortuga TPB.V1
    Amp1: W4S MC-5, AMP2: W4S MMC-7
    Front: Salk SoundScape 8's, Center: Salk SoundScape C7
    Surround: Polk FXIA6, Surround Back: Polk RTIA9, Atmos: Polk 70-RT
    Subs: 2 - Rythmik F25's
    IC & Speaker Cables: Acoustic Zen, Wireworld, Signal Cable
    Power Cables: Acoustic Zen, Wireworld, PS Audio
    Room Treatments: GIK Acoustics
  • BlueFoxBlueFox Posts: 11,518
    edited July 2014
    Nice. I don't know how I missed this. Sometimes it seems new posts disappear from 'new posts' even if you never read it.

    Anyway, I'm glad they worked for you. I just use my ears and memory for evaluation, and I am relieved your measurements and experience parallel my experience. I'm also glad I only had to use one .75 meter cable versus three 1 meter cables. :smile:

    Is this a typo?
    The RAL DB25 cables are thick and stiff. I did not want to pull my 9,957 pound equipment cabinet from the wall,
    Bud - Silicon Valley

    Lumin X1
    Sony XA-5400ES SACD
    Pass XP-22 pre, X600.5 amps
    Magico S5 MKII Mcast Rose speakers, SPOD spikes

    Shunyata Triton v3/Typhon QR on preamp, Denali 2000 (2) on amps
    Shunyata Sigma XLR analog ICs, Sigma speaker cables
    Shunyata Sigma HC (2), Sigma Analog, Sigma Digital, Z Anaconda (3) power cables

    Mapleshade Samson V.3 four shelf solid maple rack, Micropoint brass footers
    Three 20 amp circuits.
  • deronb1deronb1 Posts: 4,671
    edited July 2014
    Now THATS a post!......my pee pee shrunk up a bit. Enjoyable read and far above my pay grade, but made some sense
  • DarqueKnightDarqueKnight Posts: 6,539
    edited July 2014
    BlueFox wrote: »
    I'm also glad I only had to use one .75 meter cable versus three 1 meter cables. :smile:

    Yeah, the rabbit hole can be economically challenging at times.
    BlueFox wrote: »
    Is this a typo?
    The RAL DB25 cables are thick and stiff. I did not want to pull my 9,957 pound equipment cabinet from the wall,

    It was an exaggeration to emphasize how much I hate pulling my heavy equipment cabinet away from the wall. The cabinet and gear actually weigh 785 pounds.
    "So hot it burns Mice!"~DK
    "Polk SDA-SRSs are hopelessly out of date both sonically and technologically... I see no value whatsoever in older SDA speakers."~Audio Asylum Member
    "Knowledge, without understanding, is a path to failure."~DK
    "Those who irrationally rail against something or someone that is no threat to them, actually desire (or desire to be like) the thing or person they are railing against."~DK
  • Moose68BashMoose68Bash Posts: 3,578
    edited August 2014
    Somehow, I got the hyperbole in the "9,957" number. I guess I've been reading too many posts!

    Thank you for another exemplary post.

    DarqueKnight, when are you going to get more committed to two-channel sound systems? :~)
    Family Room, PS Audio PW Transport, DirectStream DAC; AQ Sky XLRs, Perreaux SM6 MKII Pre; AQ Sky XLRs, Perreaux Prisma 750 Amps or CAT 600.2 Dualmono Amp, Morrow SP7 Speaker Cables, SDA SRS 1.2tls (RD0198s, Dreadnought, Black Hole 5, Acousta-Stuf, Dynamat Extreme, JBWeld. Vr3 Mods: "The Abbot" Monastery-Level Xovers, Custom Internal Wiring, Binding Post Plates, & SDA ICs).

    Exercise Room, Wadia 171 iPod Dock, PS Audio PerfectWave MkII DAC, AQ Sky XLRs, Perreaux SM6 Preamp, AQ King Cobra RCAs, Perreaux PMF3150 Amp, Dreadnought, Supra Rondo 4x2.5 Speaker Cables, SDA 1Cs (Vr3 Mods Xovers).

    Synology 713+ NAS on Gigabit LAN serving PW MkII DAC & DirectStream DAC.
  • BlueFoxBlueFox Posts: 11,518
    edited August 2014
    It appears either pin 1 or 2 isn't used. Is that correct, or is the diagram ambiguous? If ambiguous I can just imagine somebody making an incorrectly wired cable. :eek:
    Bud - Silicon Valley

    Lumin X1
    Sony XA-5400ES SACD
    Pass XP-22 pre, X600.5 amps
    Magico S5 MKII Mcast Rose speakers, SPOD spikes

    Shunyata Triton v3/Typhon QR on preamp, Denali 2000 (2) on amps
    Shunyata Sigma XLR analog ICs, Sigma speaker cables
    Shunyata Sigma HC (2), Sigma Analog, Sigma Digital, Z Anaconda (3) power cables

    Mapleshade Samson V.3 four shelf solid maple rack, Micropoint brass footers
    Three 20 amp circuits.
  • DarqueKnightDarqueKnight Posts: 6,539
    BlueFox wrote: »
    It appears either pin 1 or 2 isn't used. Is that correct, or is the diagram ambiguous? If ambiguous I can just imagine somebody making an incorrectly wired cable. :eek:

    Pin 1 is one of the left voltage + connections. Pins 2 and 3 are jumpered together and are one of the left voltage - connections.
    "So hot it burns Mice!"~DK
    "Polk SDA-SRSs are hopelessly out of date both sonically and technologically... I see no value whatsoever in older SDA speakers."~Audio Asylum Member
    "Knowledge, without understanding, is a path to failure."~DK
    "Those who irrationally rail against something or someone that is no threat to them, actually desire (or desire to be like) the thing or person they are railing against."~DK
  • BlueFoxBlueFox Posts: 11,518
    Have you noticed any further improvements? I have become used to mine and am starting to wonder where to get my next fix. :)

    I am now putting my effort into bringing up my HT/surround/spare stereo up a level.
    Bud - Silicon Valley

    Lumin X1
    Sony XA-5400ES SACD
    Pass XP-22 pre, X600.5 amps
    Magico S5 MKII Mcast Rose speakers, SPOD spikes

    Shunyata Triton v3/Typhon QR on preamp, Denali 2000 (2) on amps
    Shunyata Sigma XLR analog ICs, Sigma speaker cables
    Shunyata Sigma HC (2), Sigma Analog, Sigma Digital, Z Anaconda (3) power cables

    Mapleshade Samson V.3 four shelf solid maple rack, Micropoint brass footers
    Three 20 amp circuits.
  • DarqueKnightDarqueKnight Posts: 6,539
    I haven't heard any further improvements.
    "So hot it burns Mice!"~DK
    "Polk SDA-SRSs are hopelessly out of date both sonically and technologically... I see no value whatsoever in older SDA speakers."~Audio Asylum Member
    "Knowledge, without understanding, is a path to failure."~DK
    "Those who irrationally rail against something or someone that is no threat to them, actually desire (or desire to be like) the thing or person they are railing against."~DK
  • headrottheadrott Posts: 5,428
    I haven't heard any further improvements.

    Perhaps if you blind test it? :o
    Relayer-Big-O-Poster.jpg
    Taken from a recent Audioholics reply regarding "Club Polk" and Polk speakers:
    "I'm yet to hear a Polk speaker that merits more than a sentence and 60 seconds discussion." :\
    My response is: If you need 60 seconds to respond in one sentence, you probably should't be evaluating Polk speakers.....


    "Green leaves reveal the heart spoken Khatru"- Jon Anderson

    "Have A Little Faith! And Everything You'll Face, Will Jump From Out Right On Into Place! Yeah! Take A Little Time! And Everything You'll Find, Will Move From Gloom Right On Into Shine!"- Arthur Lee
Sign In or Register to comment.

Howdy, Stranger!

It looks like you're new here. If you want to get involved, click one of these buttons!