Pass Labs X600.5 Monoblock Power Amplifiers

DarqueKnight
DarqueKnight Posts: 6,760
edited April 2014 in Electronics
Introduction

X6005DarkMeter-s_zps0f160682.jpg
Figure 1. The X600.5 meter measures current draw. Some people wish the meter light could be turned off.
I like it.


The Parasound Halo JC 1 monoblock power amplifiers in my two channel reference quality audio system were recently replaced with Pass Laboratories X600.5 monoblocks. The X600.5's higher power reserves, faster transient response and lower noise characteristics facilitated a more realistic stereophonic sound stage with heavier images, greater delineation of space between images, greater image stability, greater detail, greater clarity and spectacular bass response. The X600.5s are nearly 2.5 times the cost of the JC 1s. In terms of enhanced stereophonic performance, I do not think that I paid a diminishing returns penalty with this purchase. In terms of listening pleasure, I think the X600.5s are the best audio investment I have made to date.

A few words regarding the design philosophy behind the X600.5 provide some insight. The following is taken from the X600.5 manual:

"The X.5 Series amplifiers have the tremendous dynamic range (>140 dB) to do justice to the high-resolution digital recordings of the 21st Century and the elegance to retrieve the micro dynamics offered by the most sensitive loudspeakers. The simple but powerful circuitry moves easily from total silence to explosive transient and back to silence without a trace and without information loss. Very unlike conventional high power amplifiers, they provide this level of power with a subtlety befitting some of the better tube amplifiers. This performance is consistence across the audio spectrum and the amplifiers are unconditionally stable into all speaker loads."


Furthermore:

"Listening to my amplifiers is like listening to tubes, but without the hassle." - Nelson Pass


The Luminous Meters

My meter needles remain stationary unless heavy bass content is playing. For example, on Whitney Houston's "My Love Is Your Love" ("Greatest Hits" CD) the meter needles moved back and forth about one millimeter. The movements were in synch with the song's Reggae-ish bass beats.

Break In

The owner's manual does not specifically address break in requirements. It only mentions that the amps require an hour to fully warm up. The Pass Labs website states the following regarding break in:

"Most improvement comes in the first 24-36 hours, after which the amps will continue to improve as long as they are left on."


The dealer recommended playing music for five days straight before doing critical listening. Music was supplied by analog and digital media during listening sessions and by a tuner at other times.

Right out of the boxes, the X600.5's increase in overall clarity, detail and sound stage characteristics over the JC 1s was immediately obvious. I was not pleased with the initial bass performance, which seemed disjointed from the rest of the sonic presentation and which did not have anywhere near the JC 1's bass speed, bass clarity, bass detail and bass articulation. The X600.5s did produce more tactile sensation. It took four days of playback for the X600.5s to equal the JC 1's bass presentation. After eight days, the X600.5's bass performance exceeded that of the JC 1s. I have not heard any changes or improvements, in any performance aspect, since the eighth day.

X6005Boxes-s_zpseecad9e0.jpg
Figure 2. Two big boxes showed up at my door exactly one week after placing the order.

Heat Load

The temperatures quoted in this section were taken after break in was completed (eight days on continuously, 145 hours of music play). The room temperature is maintained at 72 degrees F.

DigitalTherms-s_zps1a93c024.jpg
Figure 3. Temperature measurements were taken with a group of Accurite digital thermometers (made in
Red China (get over it), and purchased at Walmart for $5 each (get over that too!)).


X6005LeftInstall-s_zps43e2bec8.jpg
Figure 4. I had just enough room, 3/8" on each side, to slide in the 19" wide X600.5's. I found out that
those aggressively sculpted heat sinks are big for good reason.


The X600.5s draw more idle current than the JC 1s, but run cooler than the JC 1s when idling and just a little hotter than the JC 1s when playing music. The X600.5s generate more heat, but dissipate that heat over a much larger case and much larger heat sinks. The JC 1s are biased into class A for the first 25 watts compared to the X600.5's first 80 watts. The X600.5's case encloses 3,895 cubic inches compared to the JC 1's 2,173.5 cubic inches (increase of 79%). In addition to larger size, the X600.5 case is much thicker and heavier, 132 pounds compared to 64 pounds for the JC 1. The current draws for the JC 1 and X600.5 are shown in table 1.
Table 1. JC 1 and X600.5 Current Draws.
JC1-X600-5CurrentDraw-s_zps174eb1ce.jpg

2CHEqCab-s_zpsda0d9042.jpg
Figure 5. The X600.5s are installed in a Salamander Synergy Triple 30 audio credenza with an open back and
metal mesh doors and sides.


FanMountedRear-s_zps9155dd81.jpg
Figure 6. Quiet (29 dB) fans were installed above the X600.5s, but they are not required during normal
operation. I cannot hear the fans when music is playing and can barely hear them when no music is playing.


(Refer to figure 5 for component location references.) During idling and playback at reasonable levels (85-90 dB-C) the X600.5's heat sinks and the cases of the other components do not reach unsafe temperatures. The X600.5's heat sinks reach an average idle temperature of 117 degrees F. The XP-25 preamp above the left X600.5 reaches a case temperature of 104 degrees F. The XP-25 preamp power supply above the right X600.5 reaches a case temperature of 95 degrees F. The components in the middle, going from top to bottom, reach temperatures of 96, 96, 94, and 85 respectively.

After four hours of playback with material with moderate to heavy bass content, The X600.5's heat sinks reach an average idle temperature of 127 degrees F. The XP-25 preamp above the left X600.5 reaches a case temperature of 108 degrees F. The XP-25 preamp power supply above the right X600.5 reaches a case temperature of 98 degrees F. The components in the middle, going from top to bottom, reach temperatures of 99, 99, 90, and 89 respectively.

The temperature on the top of the equipment cabinet reached 75 degrees F during idling and 77 degrees F during music play. The X600.5s do not dump a lot of heat into my 3570 cubic foot living room (21'L x 17'W x 10'H). I did not find them to be the "space heaters" that others have complained about.

Turning on the fans while playing music lowered the amp heat sink temperatures by 5 degrees F and the case temperatures of the other components by 7 to 9 degrees F. I would only run the fans in situations where I needed to play music for many hours and days continuously, such as when breaking in a new component.

WestekOutletSwitch-s_zpse7de98fa.jpg
Figure 7. The fans are turned on and off with a radio frequency remote controlled outlet switch.

An infrared outlet switch would have provided the convenience of using my universal remote to turn the fans on and off, but I would have had to put the switch in a line of sight location rather than out of sight behind the cabinet.

Fan model and vendor: PQ Fan, HomeTheaterCooling.com.
Outlet switch model and vendor: Westek RFK306LC, Home Depot.
15 Amp White Triple Adapter: Leviton R52-00531-00W, Home Depot.

Construction Quality

I usually can find something to complain about with regard to construction quality and/or aesthetics, but I'm stumped here. I could nitpick about my preference for black-faced components, but my amplification gear is behind black metal mesh doors...so the silver color is no big deal.

X6005Powered-s_zpsae3b5016.jpg
Figure 8. Initial power-up and function checkout.

X6005RearRv-s_zps40e63be3.jpg
Figure 9. Those handles really helped out with pulling the amps out of their boxes and with maneuvering the
amps into the equipment cabinet.


X600_5Inside2013-s_zpscd801673.jpg
Figure 10. The obligatory peek under the hood.

As I noted in my XP-25 phono preamp review, the XP-25 is more affected by magnetic fields than my previous Xono phono preamp. Putting four large sheets of cold rolled steel under the XP-25's control module cabinet shelf and four smaller steel sheets under the left side of the control module's chassis (where the input circuitry is located) significantly reduced the hum to a faint level. Adding more steel sheets did not reduce the hum further. I thought I would have more hum issues with the more powerful X600.5, but I actually needed less shielding. I achieved the same level of hum reduction using only the four small sheets under the XP-25's input circuitry. Apparently, the X600.5s use a better shielded transformer.
Proud and loyal citizen of the Digital Domain and Solid State Country!
Post edited by DarqueKnight on
«1

Comments

  • DarqueKnight
    DarqueKnight Posts: 6,760
    edited April 2013
    Listening Evaluations

    Refer to figures 11 and 12 during discussions of spatial properties.

    2Ch-Front-s_zps6a45c899.jpg
    Figure 11. Two channel audio system viewed from listening position.

    2CHLeft-s_zps71e68871.jpg
    Figure 12. Two channel audio system viewed from left side.

    (Refer to figure 11.) Replacing the veteran JC 1's with the brand new X600.5s resulted in an immediate contraction of the sound stage in all dimensions. The train sound effect from Sheila E's "Train A' Going" ("Writes of Passage" CD) normally starts at the left wall, which is three feet from the left speaker, continues along the top of the sound stage just under the tops of the speakers and fades away at the right side of the door arch, which is 7 feet from the right speaker. With the new, unbroken in X600.5s, the train started at the vertical and horizontal middle of the left speaker, continued along the top of the audio equipment cabinet, and stopped in the middle of the right speaker.

    (Refer to figures 11 and 12.) On Dave Brubeck's "Take Five" ("Time Out" SACD), the piano is normally behind the chair at the right, the drum kit extends from the left wall to the right edge of the left speaker, the saxophone is immediately at the right edge of the left speaker and the bass is in the center. With the unbroken-in X600.5s, the saxophone was pulled to the center and shared space with the bass. The piano moved from behind the chair at the right to the space between the right speaker and the right chair. The drum kit moved three feet to the right in front of the left speaker.

    It took three days for the sound stage to return to it's pre-X600.5 dimensions. After that time, there were no expansions of sound stage dimensions, but there were significant improvements in image weight, the sense of space between in sound images, clarity and detail. The improved transient response facilitated a greater sense of pace, rhythm and timing. The X600.5 was able to supply more power for demanding transients at the beginning of music passages. Since these initial transients had been previously muted, the impression was that the music sounder "faster" and "livelier" because it was starting "earlier" at points previously unheard.

    From the first note of playback on the first day, the improvement in high frequency weight and detail was immediately obvious. Saxophone reed sound and female voices acquired more clarity, weight and detail. I never realized how beautiful Whitney Houston's voice was until I heard it through the X600.5s...and I have heard her live in concert and I have heard her recordings on many high resolution stereo systems. Her a cappella into for "I Will Always Love You" ("Greatest Hits" CD) was both eerie in its realism and transfixing. I jumped back to the beginning of this intro many times before I allowed the song to play through. When the musical accompaniment began, her voice was clearly the most powerful and most articulate instrument in the sound stage.

    The scenario of repeating the beginning of familiar songs was repeated many times because I was hearing new details in the music. I heard improvements in tactile sensation, clarity, detail, bass articulation, and Krell-ish bass slam (which I did not think was possible with Mosfet transistors) up to the eighth day.

    I am particularly impressed with the clarity, weight and resonance of instruments that are plucked (bass and guitar) and struck (piano, Fender Rhodes, drums, xylophone). Apparently, I did not previously have enough power available to fully flesh out the notes of such instruments. I imagine that there is another level of realism to be discovered if I go even higher in amplifier power.

    In summary, the X600.5 "paints" a more realistic, more complete, more satisfying, more holographic, more emotionally thrilling stereophonic picture. The X600.5s provided Such Good Sound that I am now wondering what the X1000.5s sound like...but that question will have to be addressed in the future, when I am more dedicated to audio than I am now and when I have a dedicated listening room.

    2Ch-Front-Dark-s_zps4af1512e.jpg
    Figure 13. It's easier to reach out and "touch" the phantom images with the lights down low.

    JC1sBidFarewell-s_zps47ddee9e.jpg
    Figure 14. The JC 1s provided many hours of listening pleasure, but my stereo system evolution...like a
    shark, must continue to go forward. I'll sentimentally miss the JC 1s, even though I've moved on to better
    things.


    MysteriousMonolith-s_zps6f3251fa.jpg
    Figure 15. The Mysterious Monoliths respect the way that the X600.5s "handle" them.

    Historical Perspective

    So much has changed in my audio life during the last seven years. Careful and consistent listening causes your ears to evolve. As I studied and listened more, I became increasingly interested in the aural satisfaction brought by higher resolution stereo systems.

    2CH-2006-s2_zps7aa7c5e8.jpg
    Figure 16. Two channel stereo system - early 2006.

    The starting point - two channel stereo system in early 2006:

    Adcom GFP-750 Preamplifier
    Adcom GCD-750 HDCD Player
    Adcom GFA-5802 Power Amplifier
    Yamaha PF-800 Turntable
    Nakamichi CA-5A II Preamplifier Used As Phono Stage
    Yamaha MC-705 Moving Coil Cartridge
    Monster Z3 Reference Speaker Cables
    Signal Cable Silver Resolution XLR And RCA Interconnects
    Signal Cable MagicPower Power Cords
    Polk Audio SDA SRS 1.2TL True Stereo Loudspeakers
    Bello AT-4103 Audio Rack
    One Dedicated AC Outlet For Entire System

    The engineers at Adcom had a list of modifications that would address the cost-cutting measures applied to the GFA-5802 power amplifier. I still have a twinge of regret that I never got around to doing the mods.

    As I have moved up in amplifier quality from the Adcom GFA-5802, to the Parasound Halo JC 1s (4.5X the cost of the Adcom) to the Pass Laboratories X600.5s (11X the cost of the Adcom, 2.44X the cost of the Parasound), I have achieved more realism, more holography, more detail, more clarity, more musicality...and more thrills. Very large reserves of clean, fast, and stable power impart improvements in clarity, liquidity, tactile sensation and emotional impact to well-recorded music that must be heard to be believed.

    Performance Specifications

    Performance specifications provide some insight, but specs can be misleading if you don't know the design specifics. For example, the JC 1 has a slew rate of 130 V/usec compared to the X600.5's "mere" 50 V/usec. That might lead some to believe that the JC 1 is the faster, more agile and more nimble amplifier. Nelson Pass explained the X600.5's lower slew rate this way:

    "In the X600.5 the symmetric voltage gain stage will peak out at about 100 mA. We also take advantage of balanced output stages (halving the slew requirement), and last but not least, we bias the amplifiers high."

    Another thing to consider about specs is that you often don't know if the manufacturer uses rates performance based on average or typical use, worst case, ot ideal conditions. Pass uses conservative ratings, therefore the "typical" user will experience performance much better than spec. Regarding the slew rate spec previously mentioned:

    "...we rate the slew rate as 50 V/uS, but I took a look at one on the bench today and saw about 80 V/uS. You can get a sloppy 160 V/uS if there's no load." - Nelson Pass

    A spreadsheet comparing the JC 1's and the X600.5's specs is attached below.

    Associated Equipment

    Pass Labs XP-30 line level preamplifier
    Pass Labs XP-25 phono preamplifier
    Parasound Halo JC 1 monoblock power amplifiers (400 watts into 8 ohms/800 watts into 4 ohms)
    Cary Audio CD 306 Pro Version SACD player
    Teres Audio Model 255 turntable
    Graham Phantom I Tonearm with Phantom II titanium arm wand
    Ortofon MC Windfeld phono cartridge
    AudioQuest LeoPard phono interconnect
    AudioQuest Sky XLR interconnects
    AudioQuest Everest speaker cables
    Polk Audio SDA SRS 1.2TL loudspeakers (extensively modified, 4 ohms nominal impedance)
    PS Audio P10 AC Regenerator
    PS Audio AC 12 and Premier SC power cords
    PS Audio PowerBase isolation platforms under SACD player and turntable
    Black Diamond Racing Mark 4 isolation cones and Jumbo Pit isolation pucks under SACD player and turntable.

    References

    Pass-Labs-XP-30-Line-Level-Preamplifier

    Pass-Labs-XP-25-Phono-Stage-Is-It-That-Much-Better-Than-The-Xono

    The-Last-Amplifier-Project-Pass-Labs-X600.5-Monoblocks
    Proud and loyal citizen of the Digital Domain and Solid State Country!
  • nooshinjohn
    nooshinjohn Posts: 25,034
    edited April 2013
    ...but that question will have to be addressed in the future, when I am more dedicated to audio than I am now

    I seriously think you fell down that rabbit hole a very long time ago.:cheesygrin:


    Great review and congrats.
    The Gear... Carver "Statement" Mono-blocks, Mcintosh C2300 Arcam AVR20, Oppo UDP-203 4K Blu-ray player, Sony XBR70x850B 4k, Polk Audio Legend L800 with height modules, L400 Center Channel Polk audio AB800 "in-wall" surrounds. Marantz MM7025 stereo amp. Simaudio Moon 680d DSD

    “When once a Republic is corrupted, there is no possibility of remedying any of the growing evils but by removing the corruption and restoring its lost principles; every other correction is either useless or a new evil.”— Thomas Jefferson
  • polkfarmboy
    polkfarmboy Posts: 5,703
    edited April 2013
    I think you should freelance for magazines
  • zane77
    zane77 Posts: 1,696
    edited April 2013
    Your reviews are always so detailed and enjoyable to read, thanks for sharing.
    Home Theater
    Onkyo PR-SC5508 Sharp LC-70LE847U
    Emotiva XPA-5 Emotiva XPA-2 Emotiva UPA-2
    Front RTi-A9 Wide RTi-A7 Center CSi-A6 Surround FXi-A6 Rear RTi-A3 Sub 2x PSW505
    Sony BDP-S790 Dishnetwork Hopper/Joey Logitech Harmony One Apple TV
    Two Channel
    Oppo 105D BAT VK-500 w/BatPack SDA SRS 2.3 Dreadnought Squeezebox Touch Apple TV
  • Toolfan66
    Toolfan66 Posts: 16,834
    edited April 2013
    I think you should freelance for magazines

    Agreed!!
  • chris23120
    chris23120 Posts: 95
    edited April 2013
    Great Review! That's an awesome set up you have. What do you plan to do with the JC 1's ? And how far have you made the Needles move on the x600.5's?
    Samsung UN55C6500 55" LED
    Onkyo TX-NR3007
    Polk Audio RT5000
    -RT3000 front
    -CS1000 center
    -FX1000 dipole
    Polk Audio PSW1000 5.1 sub
    Polk Audio microPRO 4000 x2 5.2 subs:biggrin:
  • Jetmaker737
    Jetmaker737 Posts: 1,000
    edited April 2013
    Congratulations on your acquisition of those beautiful amplifiers. Excellent and informative write up as well. You've come a long way in 7 years!
    SystemLuxman L-590AXII Integrated Amplifier|Sonus Faber Cremona Loudspeakers|PS Audio Directream Jr|Sansui TU-9900 Tuner|TEAC A-6100 RtR|Nakamichi RX-202 Cassette
  • Drenis
    Drenis Posts: 2,871
    edited April 2013
    Great review! Enjoyed the read like all your write ups DK.

    I would be happy to try the baby models.
  • DarqueKnight
    DarqueKnight Posts: 6,760
    edited April 2013
    I seriously think you fell down that rabbit hole a very long time ago.:cheesygrin:

    No, I'm still standing at the edges trying to decide if I want to jump in.:wink:
    chris23120 wrote: »
    What do you plan to do with the JC 1's?

    Once I decided to keep the X600.5s, the JC 1s were traded in.
    chris23120 wrote: »
    And how far have you made the Needles move on the x600.5's?

    Three millimeters from the idle position. This was at a constant sound pressure level of 110 dB-C playing music with a heavy pulsating bass beat. The volume control was set at 75 (it ranges from 0 to 99 in 1 dB increments).
    Proud and loyal citizen of the Digital Domain and Solid State Country!
  • F1nut
    F1nut Posts: 49,708
    edited April 2013
    Sweeeeeeeeeeeeeeeeeeeet!
    Political Correctness'.........defined

    "A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."


    President of Club Polk

  • headrott
    headrott Posts: 5,484
    edited April 2013
    Sounds like some excellent amps Ray! I'm happy for you.
    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
  • jumpindick
    jumpindick Posts: 428
    edited April 2013
    great set up. Congratulations! By the way, great review as well. Whay kind of speakers are those?
  • Ducati Guy
    Ducati Guy Posts: 160
    edited April 2013
    from my perspective you are at the end of the rabbit hole,
    thanks for letting us know what it's like there.
    can't imagine any more "updates" are in the works.
    Love, Love the system.
  • DarqueKnight
    DarqueKnight Posts: 6,760
    edited April 2013
    jumpindick wrote: »
    Whay kind of speakers are those?
    Polk Audio SDA SRS 1.2TL loudspeakers (extensively modified, 4 ohms nominal impedance)
    Ducati Guy wrote: »
    can't imagine any more "updates" are in the works.

    There's always something better around the corner.
    Proud and loyal citizen of the Digital Domain and Solid State Country!
  • mrbiron
    mrbiron Posts: 5,711
    edited April 2013
    There's always something better around the corner.
    With what you have, it's hard to imagine something better. From all the reviews you've put out, it seems the speakers aren't moving from their current location and now you're sitting pretty as Cleanup in the Major's with your equipment.

    With that said....what are in your sites next?!
    Where’s the KABOOM?!?! There’s supposed to be an Earth shattering KABOOM!!!
  • DarqueKnight
    DarqueKnight Posts: 6,760
    edited April 2013
    mrbiron wrote: »
    With that said....what are in your sites next?!

    Sending my Graham Phantom I tonearm to the factory to be upgraded to the Phantom II Supreme.
    Proud and loyal citizen of the Digital Domain and Solid State Country!
  • monepolk
    monepolk Posts: 1,140
    edited April 2013
    Great review, great system. Nice that you included progression of your system.
  • drumminman
    drumminman Posts: 3,396
    edited April 2013
    Great review as always. If you're not at the pinnacle, you can hit it with a rock from where you stand :wink:
    "Science is suppose to explain observations not dismiss them as impossible" - Norm on AA; 2.3TL's w/sonicaps/mills/jantzen inductors, Gimpod's boards, Lg Solen SDA inductors, RD-0198's, MW's dynamatted, Armaflex speaker gaskets, H-nuts, brass spikes, Cardas CCGR BP's, upgraded IC Cable, Black Hole Damping Sheet strips, interior of cabinets sealed with Loctite Power Grab, AI-1 interface with 1000VA A-L transformer
  • kayhikski
    kayhikski Posts: 1
    edited March 2014
    Hello there,

    Great article. I recently outfitted my Salamander Triple 30 with 2x JC-1 Monoblocks in the same configuration as your X600.5's. I am running them in low bias mode while they break in and while I await an order of cooling fans from HTC. I was wondering, how did you attach the fans .. are they simply bolted to the back of one one of the shelves?

    Thanks!
  • DarqueKnight
    DarqueKnight Posts: 6,760
    edited March 2014
    kayhikski wrote: »
    Hello there,

    Great article. I recently outfitted my Salamander Triple 30 with 2x JC-1 Monoblocks in the same configuration as your X600.5's. I am running them in low bias mode while they break in and while I await an order of cooling fans from HTC. I was wondering, how did you attach the fans .. are they simply bolted to the back of one one of the shelves?

    Thanks!

    Welcome to the forum. Sorry about the delay in responding. Due to a glitch in the forum software, I no longer get email notifications when someone responds to one of my threads. I only saw your question while revisiting the thread in preparation for a one year update report.

    I used clothes hanger wire to make "clips" to attach the fans to the rear of the cabinet shelves. I cut a 13" section of wire from the straight part of the hanger and bent it into a "U" shape with each side 6" long and the bottom 1" long. I then bent the sides inward toward each other so that the ends crossed over each other. The crisscrossing provided tension to hold the fan in place. There were holes at each corner of the fan frame. A "U" bracket was inserted into each of the upper corner holes and the fan was slipped onto the rear of the shelf.

    In figure 6, you can see the wire protruding from the upper right mounting hole of the fan.
    Proud and loyal citizen of the Digital Domain and Solid State Country!
  • steveinaz
    steveinaz Posts: 19,521
    edited March 2014
    That's the stuff hi-fi dreams are made of. Spectacular!
    Source: Bluesound Node 2i - Preamp/DAC: Benchmark DAC2 DX - Amp: Parasound Halo A21 - Speakers: MartinLogan Motion 60XTi - Shop Rig: Yamaha A-S501 Integrated - Shop Spkrs: Elac Debut 2.0 B5.2
  • erniejade
    erniejade Posts: 6,288
    edited March 2014
    Great review! Sweet looking system and that turntable looks like a work of art!
    Musical Fidelity Tri-Vista 300, Audioquest Thunderbird Zero Speaker Cable, Tyler Highland H2, Audioquest Thunderbird Interconnect, Innuos Zen MK3 W4S recovery, Revolution Audio Labs USB & Ethernet, Border Patrol SE-I, Audioquest Niagara 5000 & Thunder, Cullen Crossover II PC's.
  • ZLTFUL
    ZLTFUL Posts: 5,640
    edited March 2014
    Yup...still hate Ray... (In the friendliest and most respectful sense of the word of course.) :wink:
    "Some people find it easier to be conceited rather than correct."

    "Unwad those panties and have a good time man. We're all here to help each other, no matter how it might appear." DSkip
  • DarqueKnight
    DarqueKnight Posts: 6,760
    edited April 2014
    Introduction

    One year out I am still thrilled with my investment in the X600.5s, which were installed on 4/10/13. The amp's sound significantly improved during the first 8 days of use, then reached a performance plateau, then after a month of being on 24/7, there was a further increase in image weight and bass weight. No further improvements or changes were observed until vibration abatement was applied in October of 2013 and no improvements or changes were observed thereafter. The amps have been left on continuously since installation and have only been turned off for very brief periods of time when switching components or cables during equipment measurements or trials.

    Pass Labs introduced a ".8" series of amps in January of 2014 that has higher class A output. In the case of the X600.8, it offers 100 watts of class A operation compared to the X600.5's 80 watts of class A operation. The X600.8 costs 18% more than the X600.5. Since I am still on a "honeymoon" with the X600.5s, it will be a while before I consider upgrading.

    Meter Gymmastics

    Those of you who are not Pass amplifier owners may want to skip this section since "meter movement" is somewhat of an inside joke.:twisted: The meter movement of a Pass Labs power amplifier indicates the state of bias current at a particular time. When the needle is stationary, the amplifier is operating in pure class A mode. When the needle moves, it indicates class AB operation.

    I only see my meters move under two conditions: (1) Heavy bass content during at normal listening levels. (2) Heavy bass content during higher than normal listening levels. Here are two example videos. The videos were taken with the following equipment and were posted to YouTube straight out of the camera with no video or audio post processing:

    Camera: Nikon D800 (Set at ISO 2200, 30 fps, f/3.5, 1080p)
    Lens: Nikon Nikkor AF-S f/2.8 24-70mm Zoom
    Microphone: Nikon ME-1 Stereo Microphone (70-16,000 Hz FR) mounted on a tripod.

    The music in the first video is "Isunova Pi" by E. S. Posthumous ("Cartographer" CD). The needle moved during the heaviest bass notes, most notably during the first 20 seconds. The average sound pressure level was 90 dB-C. The XP-30 preamp volume was set at 64.
    Video 1. Meter movement at normal listening levels.

    The music in the second video is "Your Love Is My Love" by Whitney Houston ("Whitney's Greatest Hits" CD). The needle moved constantly during the driving bass beats. The sound level was turned up to 72 to get an average sound pressure level of 104 dB-C. This resulted in easily noticeable meter movement (and the need to wear ear plugs). At normal listening levels the meter barely moved during the bass beats.
    Video 2. Meter movement at high listening levels.

    I was surprised the audio came out as well as it did considering the D800's relatively "noisy" audio circuits (which are optimized for voice) and the limited frequency response of the "cheap" ME-1 microphone.

    Increased Electricity Usage

    As previously mentioned, I prefer to keep my power amps on continuously. The X600.5s draw 25% more current and consume 25% more power at idle than my previous power amps, Parasound Halo JC 1s. Table 1 shows the differences in idle current draw and idle power consumption between the two amplifiers.
    Table 1. Parasound Halo JC 1 and Pass Laboratories X600.5 Idle Power Consumption
    JC1-X600-5CurrentDraw-s_zps174eb1ce.jpg

    Table 2 shows my electricity bills before and after (in red) the X600.5s were in stalled on 4/10/13. The June 2013 bill, which covered the period from April 23, 2013 to May 22, 2013 was the first full month of X600.5 use.
    Table 2. Electricity Bills Before And After X600.5 Installation
    ElectricityBills-AfterX600_5-s_zpsa8b38e15.jpg

    At $0.09 per kilowatt hour, the JC 1s cost $41.60 per month to run continuously. The X600.5s cost $55.66 per month to run continuously, which was an increase of 33.8% ($14.06) over the JC 1s...and it was/is worth it!:biggrin: All the amounts in red in table 2 would be $14.06 less if I still had the JC 1s.

    Audio System Upgrades After The X600.5s

    I've done a tweak hear or there during the preceding 12 months. Nothing major, just some further efforts in electrical and mechanical noise abatement. It's nice to be able to sit and listen without thinking about a bucket list of audio projects.

    1. Black Hole 5 vibration damping material for SDA SRS 1.2TL loudspeakers. (4/26/13)
    2. Dynamat Xtreme vibration damping material for XP-30 and XP-25 preamps and X600.5 power amps. (10/11/13)
    3. Dynamat Xtreme vibration damping material for Cary CD 306 PV SACD/CD player. (10/12/13)
    4. PS Audio AC 12 power cords for preamplifiers and source components. (11/09/13)
    5. AudioQuest Perfect Surface Silver jumpers for SDA SRS 1.2TL loudspeakers. (4/09/14)
    Proud and loyal citizen of the Digital Domain and Solid State Country!
  • TNHNDYMAN
    TNHNDYMAN Posts: 2,145
    edited April 2014
    Come on man you've had a week now.... where's the review on the AQ jumpers? :razz:
    2-ch System: Parasound P/LD 2000 pre, Parasound HCA-1000 amp, Parasound T/DQ Tuner, Phase Technology PC-100 Tower speakers, Technics SL-1600 Turntable, Denon 2910 SACD/CD player, Peachtree DAC iT and X1asynchorus USB converter, HSU VTF-3 subwoofer.

  • DarqueKnight
    DarqueKnight Posts: 6,760
    edited April 2014
    I sent it to the AVScience forum be reviewed for scientific accuracy before publishing it here.:razz:
    Proud and loyal citizen of the Digital Domain and Solid State Country!
  • headrott
    headrott Posts: 5,484
    edited April 2014
    I sent it to the AVScience forum be reviewed for scientific accuracy before publishing it here.:razz:

    Smart move Ray (if you like "objective scientific reviews"). :razz:
    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
  • ALSATIAN in USA
    ALSATIAN in USA Posts: 127
    edited April 2014
    with all the stuff you have now you need POLK LSIM707, BW802 or more! (I was astounished when I listen FOCAL GRANDE-UTOPIA 4 years ago) The big SRS are extremely good but some say here the best sonic polk SDA are the SDA-2 ???!!!...Also, I am sure, you're SRS sound marvelous with all this electronics.
  • ZLTFUL
    ZLTFUL Posts: 5,640
    edited April 2014
    If you think his electronics feeding them are awesome, you should check out the upgrades he has done to the speakers themselves.
    "Some people find it easier to be conceited rather than correct."

    "Unwad those panties and have a good time man. We're all here to help each other, no matter how it might appear." DSkip
  • DarqueKnight
    DarqueKnight Posts: 6,760
    edited April 2014
    with all the stuff you have now you need POLK LSIM707, BW802 or more! (I was astounished when I listen FOCAL GRANDE-UTOPIA 4 years ago) The big SRS are extremely good but some say here the best sonic polk SDA are the SDA-2 ???!!!...Also, I am sure, you're SRS sound marvelous with all this electronics.

    I have not heard the Focals, but I have heard the LSiM 707 and the B&W 802. I didn't hear anything during either audition that would make me want to replace my modified 1.2TLs.
    Proud and loyal citizen of the Digital Domain and Solid State Country!