Pass Labs XA25 Anyone?

Discussion in 'Audio Hardware' started by avanti1960, Aug 18, 2021.

  1. avanti1960

    avanti1960 Forum Resident Thread Starter

    Location:
    Chicago metro, USA
    One more day of "burn in" and the serious listening starts. I have pages of notes commenting on how different recordings sound- the good with the bad.
    Truth be told at this point the Parasound a21+ sounds better overall to my ears. The Pass has some excellent moments but also too many that are slightly cringeworthy.
    The idea of one reviewer saying the Parasound sounds like grains of sand compared to the XA25 free flowing music is absolutely not what I am hearing.
    Definitely too much hype for the Pass Labs in the media which has led to some disappointment in my experiences with it. I am a little pissed off about that.
     
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  2. dividebytube

    dividebytube Forum Resident

    Location:
    Grand Rapids, MI
    Small-ish room, but I got by with only 20Ws of the Nelson Pass designed Aleph J amplifier. 88dB efficient KEF speakers.
     
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  3. Erocka2000

    Erocka2000 Forum Resident

    Location:
    Brooklyn, NY, USA
    Do you have a different preamp to try with it, just to rule that out?
     
  4. avanti1960

    avanti1960 Forum Resident Thread Starter

    Location:
    Chicago metro, USA
    my issue is not related to power- power delivery is excellent. it is related to harshness in the upper midrange / lower treble.
     
  5. avanti1960

    avanti1960 Forum Resident Thread Starter

    Location:
    Chicago metro, USA
    yes but I know it will sound worse :)
    tomorrow / next week i'll start experimenting with preamp cables.
     
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  6. Audiofan1

    Audiofan1 Well-Known Member

    Location:
    States
    Read those comments when deciding between the A21+ Pass XA25 "grains of sand " was something I had never heard with my non + A21 ! I was a bit baffled at this comment but did notice when weighing things out the overwhelming comments on the XA25 was a sometimes "lean sound" which I always attribute to upper mids / lower treble, while the A21 was not the last word here, it always came across with harmonic non offensive beauty in this range. This got me wanting the A21+ as any improvement on an already respectable sound should indeed yield a nice up tick, well a few more dollars saved and fetching a bit more for my A21 I went all in on the JC5 and while not a lot of reviews on it , most owners seem to have the same comments about it which is "its special" and what it has brought to my setup is more than expected that upper mid/lower treble response will always have two responses , one being maybe a different cable or reposition of my speakers? or a deep breath and exhale from a pleasing sound of beauty! which can lead to late night listen sessions and more music purchasing.
    When your done vetting the XA25 and find yourself still wondering I hope you consider the JC5 for audition, there is good reason why Mr. Curl uses one to drive his Wilson's.
     
    avanti1960 likes this.
  7. Morbius

    Morbius Forum Resident

    Location:
    Brookline, MA
    Clipping.
     
  8. Rick58

    Rick58 Forum Resident

    Location:
    Eagle, ID, USA
    Not to interject myself in EVERY posting ... but the Cary preamp is VERY well regarded (and drool-worthy!), probably among the best at any price. I can't imagine it isn't worthy or incompatible with the XA25 but of course anything could happen.

    Similarly, the JC5 is drool-worthy, even compared to my non + A 21. Maybe if I win the lottery ... and can also hire someone to install it! I do hope the XA25 proves itself in the end, hopefully a little more break-in will make the difference.
     
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  9. Erocka2000

    Erocka2000 Forum Resident

    Location:
    Brooklyn, NY, USA
    I didn’t mean to disparage the Cary. It was more a question of synergy. Just like I wouldn’t use a Shindo preamp with a top of the line solid state amp, some components, regardless of how good they are simply just do not mesh well.
     
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  10. bhazen

    bhazen Beware of soft-shoe shufflers

    Location:
    Newport Hills, WA
    A review of the XA25 by a fella whose opinion I respect greatly (and whose Sibelius loudspeaker is in my top 5 "most want to hear someday" designs.)

     
  11. Ontheone

    Ontheone Poorly Understood Member

    Location:
    Indianapolis
    I was thinking at first it could be a gain issue as the Cary preamp is definitely on the higher side of gain, especially in balanced mode (not applicable to XA25) but the XA25 is on the lower side of gain at only 20dB.
     
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  12. WildPhydeaux

    WildPhydeaux Picture withheld by The Authorities

    Location:
    A Parade in Dallas
    The Cary also allows for trimming the output levels, if that should be required. But the lower gain of the Pass shouldn't require that.

    Cheers,
    Robert
     
    avanti1960 likes this.
  13. pacvr

    pacvr Forum Resident

    Location:
    Maryland
    Your experience 'appears' very similar to Pass Laboratories XA25 power amplifier | Stereophile.com where Herb wrote:

    Break-in and cable issues
    Before the XA25 had even broken in, I'd almost given up on it. Its sound was unpredictable. I mean, dagnab it! How long should an amp take to wake up and play right? I had the damn thing on and playing music for at least four weeks, and still it occasionally sounded unsettlingly "different." But even on the first day I turned it on, I realized that the XA25 had an unusually solid midrange presence. Every day thereafter, I discovered more sonic wonderments—and more that I could not grok.

    Also to note: "During this extended break-in period I experimented a little with speaker cables, and quickly realized that the XA25's sound changed with the wire. I began with my usual Auditorium 23 cables: the sound was rich and natural, if maybe a bit restrained. When I switched to AudioQuest Type 4s, the sound tightened up but also became slightly grainy. When I switched to AudioQuest's GO-4, the XA25 seemed to have found its clear, open, vivacious channel."

    The Stereophile review did show that: "At moderate powers the XA25 offered low levels of distortion, but as you can see in fig.6, which plots the THD+N percentage against frequency at 8.9V—equivalent to 10W into 8 ohms, 20W into 4 ohms, and 40W into 2 ohms—the distortion did rise at higher frequencies, especially into lower impedances. This graph suggests that the XA25 not be used with loudspeakers with an impedance that drops below 4 ohms in the treble." But the Stereophile review of your speakers Harbeth Super HL5plus loudspeaker Measurements | Stereophile.com "Although the Super HL5plus has a specified impedance of 6 ohms, my measurement (fig.1) indicates that the speaker's impedance remains above 8 ohms for almost all of the audioband, and that the electrical phase angle remains relatively small. The HL5plus will therefore be an easy load for the partnering amplifier to drive, and a good match for tubed designs."

    Patience? More time to settle?
     
  14. Hope this rally pans out for you but have you thought about giving the 150.8 a shot?
     
  15. WildPhydeaux

    WildPhydeaux Picture withheld by The Authorities

    Location:
    A Parade in Dallas
    Et Tu, Khorn?

    Cheers,
    Robert
     
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  16. TEA FOR ONE

    TEA FOR ONE Listening to the world one note at a time

    Location:
    Rochester,NY
    Sometimes gear just just doesn't work out the way we'd like.
     
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  17. Seems like the X150.8 is a logical step while remaining in the Pass universe. Never know, it might be a very interesting listen.
     
  18. Tone?

    Tone? Forum Resident

    Location:
    San Francisco

    Just trust your ears man.
    In the end it’s you that is listening.

    I had the same personal experience with the NAIM X3.
    Everyone raved about it.
    I really disliked it.

    good on em for liking it. It just wasn’t for me.
     
  19. fully_articulated

    fully_articulated Forum Resident

    I'm sympathetic to your frustration @avanti1960, currently having a very similar experience with a self-built First Watt M2. Wonderful sound punctuated by moments of upper midrange harshness and dominant centre imaging. The first couple of days in particular was pretty rough. Reichert's thoughts (posted by @pacvr above) on the initial sound of the XA25 mirrors my own, less eloquent, comments made in my build thread.

    At least if the experiment fails we both have amps we enjoy to return to right?
     
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  20. mreeter

    mreeter Forum Resident

    Location:
    Midwest, USA
    Tony, I'm certainly pulling for the Pass to come around and provide you with a pleasing experience in time. But, if it doesn't, I know you were/are very fond of your previous Rogue St.100. Although they don't advertise it, Rogue will build you a St.100 "Dark". This is a nicely upgraded version of the original St. 100 that includes the following upgrades:

    -Ultra Premium coupling capacitors
    - Increased power supply storage
    - Hex Fred high speed diodes in power supply
    - Polypropylene bypass capacitors in power supply
    - Nude Vishay resistors in critical locations
    - Rhodium binding posts (Cardas)
    - Rhodium RCA jacks (Cardas)
    - Upgraded signal wiring (Cardas)
    - Telefunken and RCA small signal tubes

    Didn't know if you were aware of this or not, just something else to lose sleep over:winkgrin:
     
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  21. Slippers-on

    Slippers-on Forum Resident

    Location:
    St.Louis Mo.
    I was talking interconnects for the neutral/warm Pass Harbeths combo. The combinations of metals and the technology will be great for that combo. But the Speaker cables should be all copper as they are down stream so the Wireworld Eclipse 8 will help to balance it all out with a glorious sound. But I know your not ready to spend that kind of money.;)
     
    Last edited: Sep 18, 2021
    avanti1960 likes this.
  22. Slippers-on

    Slippers-on Forum Resident

    Location:
    St.Louis Mo.
    Bro….listen to yourself! You said the “Pass has some excellent moments, then it’s slightly cringeworthy”. Hahahaha! So why on earth are you fussing about the sound. That should tell you it’s still trying to find its self and not run in yet. My bro….it’s still changing…it will go back and forth, and when an amp is changing like that, it’s not found it’s self yet, but still running in…it will do that until it’s done. So lil bro….slow it down a bit and just wait it out. Maybe more than a weeks time but it will happen. Just to encourage you a bit, it’s isn’t the first time this has happen…others have said this about amps…..but they learned to slow it down, give the ears a vacation when it’s not ready and walk away. Give it a while bro…waiting has rewards.
     
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  23. Dream On

    Dream On Forum Resident

    Location:
    Canada
    I guess it's either going to come on point in the very near future or it will stay the same and you'll find it impossible to get past those objectionable sounds. Looking forward to seeing how it goes. I don't know much about this amp but just looked at it quickly. I must say I am surprised at how little it weighs for the power it puts out in Class A - 50 watts and all in Class A if I am reading that right, and the ability to drive difficult loads. I thought that much Class A power would necessitate a much heavier amp...like those old Classe power amps that weighed 70 pounds and still only put out 20 watts. Possibly there is more to what the Pass is doing. My old Sugden did 23 watts and it didn't like 4 ohm loads.

    I would love to hear the a21+ just based on how you rave about it. Parasound seems to just be really competent, no-nonsense design; lots of power on tap but still sounds great.
     
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  24. Audiofan1

    Audiofan1 Well-Known Member

    Location:
    States
    Definitely more run in time needed I'd say 400hrs to before passing any real judgement. I like to use the 12hrs music playback and 30 min rest (to drain the caps) till fully cooked. I use this method with all my new gear cables as well .
     
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  25. WildPhydeaux

    WildPhydeaux Picture withheld by The Authorities

    Location:
    A Parade in Dallas
    So you turn the amp off at the main switch while playing music in order to "drain the caps". Huh. How does that help to break in an amp which the manufacturer says to leave powered on all the time?

    And for cables also? What drains out of them and do you just use a little drip tray beneath them to catch the voltage drops?

    Cheers,
    Robert
     

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