Pass Labs Amplifier Fantasy

Discussion in 'Audio Hardware' started by mds, Nov 21, 2018.

  1. mds

    mds Forum Resident Thread Starter

    I've been using tubes for years and was beginning to think about solid state to rid me of tube nuisances and expenses now that I am retired. I am listening for hours each day and replacing tubes is just too expensive. I also thought my KEF Reference 3 speakers might benefit in the bass region from solid state. Pass Labs I believe would be a great compromise, tube sound, solid state reliability.

    My budget is the only constraint but for now I am exploring but not sure if I need to be class A or AB. In class A, new I am thinking of the XA30.8 and in class AB it would be the X100.8, however used I could move up one notch in power but it would be the .5 editions.

    I would love to be class A since from my research they seem to have the greatest tube sound, but would the XA30.8 be too low powered for my KEFs? Currently my tube mono blocks are 38 watts per channel and it seems plenty of power, my room is 13 ft wide by 15 ft deep. I tried a solid state 400 watt per channel amp and the bass was more detailed but wasn't sure if this was just a result of the amps being 3x more expensive and therefore of a higher quality being able to bring out more detail. Both the borrowed SS amp and my tube amps went equally deep just more detail and a bit sharper edged with the SS amp.

    Any suggestions / thoughts on power requirements and class in the Pass Labs line that would match with my KEF speakers would be appreciated. I use a Backert Labs Rhumba 1.2 preamplifier if that helps.
    Echoes Myron likes this.
  2. KT88

    KT88 Forum Resident

    The Pass amps are very expensive, so that's not a very good budget minded option. They sound very good. I like the pure class A amps, but they run very hot and maintenance can still be high due to that. I'd buy new to avoid age and abuse issues due to that. The FirstWatt amps are Nelson Pass designs and more affordable. Lots of other good sounding SS amps that are class AB and hybrid tube/D like the Rogue Audio Hydra, which is made in PA.
    Manimal, Mike-48 and jdsher like this.
  3. Mike-48

    Mike-48 Forum Resident

    Portland, Oregon
    As @KT88 said, the Pass Lab amps sound nice. Very liquid, to my ears. Be aware that even the Class AB ones run warm. For example, the X250.8 that I auditioned puts out 400 watts of heat at idle -- as much as a small space heater. For Pass (new and used), Reno HiFi in Nevada offers discounts and home trials. I found their service exemplary.

    IME, solid-state amps sound surprisingly different from one another. Others I liked were the Bryston 4B3 and Classe CA-2300, both of which should be available (and reliable) on the used market. (I have a VERY quiet room and occasionally could hear the fan of the Classe, but apparently that's not a problem for most. No review has ever mentioned that, and I'm the only one in an online forum I saw complain.)

    You might also consider the Benchmark AHB2. It doesn't offer tube "warmth," but it is extremely resolving, and I've never seen any complaints that it sounds cold or harsh. They offer a home trial.

    My points are: listen first if you can, and before buying Pass, make sure the heat won't be a problem for you.
  4. ejman

    ejman Music, fountain of life!

    I have a Conrad Johnson MF2300A which is one of the most "tube like" SS amps I've heard. I suspect the CJ SS series would probably work for your purposes.
    John, mds and Manimal like this.
  5. jonwoody

    jonwoody Forum Resident

    Washington DC
    mds likes this.
  6. TSWisla

    TSWisla Forum Resident

    There is no substitute for Pass Labs. If that is what you like, don’t let anyone try to change your mind.
    Pythonman, russk, sushimaster and 2 others like this.
  7. SandAndGlass

    SandAndGlass Twilight Forum Resident

    If you can afford Pass, then you can afford a good AC unit. :)
  8. DPR

    DPR Active Member

    I have a Pass 30.5 and an XP20 pre. It's wonderful gear. Their 30 watt class A amp are extremely underrated in power. It will likely have a lot more power than your current mono blocks. It's awesome gear, I highly recommend it. And it's extremely reliable. But it will definitely sound a bit different than you your tube gear.
    sushimaster and mds like this.
  9. Manimal

    Manimal Forum Resident

    Southern US
    Yep. Love my CJ ss amp.
    ejman, mds and SandAndGlass like this.
  10. Mad shadows

    Mad shadows Forum Resident

    Karlskrona- Sweden
    One way to get Pass on the chep is to look into Treshold gear. It's Nelson Pass original company.
    Fruff76, mds and SandAndGlass like this.
  11. KT88

    KT88 Forum Resident

    It isn't the same. Different designs. He has worked with a lot of designs over the years. Also much of that is really old now and service can be problematic and or expensive. If you want current Pass designs which are more affordable, then the First Watt name is what you will be looking at.
  12. Mad shadows

    Mad shadows Forum Resident

    Karlskrona- Sweden
    Threshold designs are as far as I know pretty ruged whit low failure rate and not that complicated to service. But I might be wrong.
    sushimaster likes this.
  13. Drew

    Drew Senior Member

    Columbus, OH
    mds and Mad shadows like this.
  14. Helom

    Helom I'll take the monkey coffins

    Try to audition a Yamaha A-S2100 or 3000.
    Thouston and G B Kuipers like this.
  15. G B Kuipers

    G B Kuipers Forum Resident

    In your situation, even if you manage to find an engaging ss amp (Pass or other) you will want to keep a tube option around. Because you will long for tube magic from time to time. So why not spread your budget to include both a nice ss amp AND a modest affordable push pull amp?

    There's no amp that can do it all. At least IME.
    Bananas&blow, mds and Helom like this.
  16. jphabc54

    jphabc54 Forum Resident

    +1 for DIY. A premium First Watt F5 can be built for ~$700 (more than half of which is for the chassis and input JFETs).

    Even if you’re not confident in your building skills, you can probably find someone to assemble one of the multiple First Watt designs for you for under $1000.

    FW is an incredible service that Nelson Pass contributes to the audiophile world.
  17. avanti1960

    avanti1960 Forum Resident

    Chicago metro, USA
    Your preamp looks really nice and should be able to keep some of the tube sound stage if you decide to switch out your power amps. Tube rolling in the Backert will also help with that (try some NOS Amperex 50's / 60's Bugle Boys if you haven't already.
    Your current mono blocks use EL34s and have an output of only 78 WPC which is significantly under powering your Ref 3s IMHO. Not necessarily in volume but in dynamics, bass quality and overall refinement so I can see the desire for a solid state power amp.
    Pass Labs amplifiers are the best by rights and seem to be conservatively rated, but I would suggest your target power output should begin at 150 WPC @ 8 ohms, puts you at the Pass X150.8, current retail $6750 which is much less than I imagined. Go for it, you will not be disappointed.
    mds likes this.
  18. Doctor Fine

    Doctor Fine Forum Resident

    Lewes, DE
    The sweet spot for me has been the John Curl designed Parasound A21 amp that came out ten years ago or so.
    As many of you know John Curl is the "other" famous amp designer besides Nelson Pass. Curl did the original Levinson amps which were so famous back in the day.
    His Parasound A21 runs in class A for the first 8 watts or so and then transitions into a very nice sounding A/B.
    Heat isn't too bad at idle and it has an auto on/off setup that is signal triggered so you won't go off and leave your "space heaters" running in the room.
    The sound quality of the A21 has been championed as near the best by reviewers in both Stereophile AND The Absolute Sound.
    I have three of them at this point.
    I would even use them (250 watts @8) on small systems as, well, why NOT?
    They are cheap enough that if you have them lying around and find you have changed speakers to larger less efficient designs you can still run them.
    And with class A at low power they work great in small rooms where the class A will come in handy.
    Things they ALSO do well is run balanced OR single ended.
    Their power is consistent and doesn't budge over time which makes them ideal for bi-amplified setups where you need consistency to keep everything in tune.
    Even the cheap knobs for individual channel volume seem to hold their values pretty well and not drift. although frankly if you have to use these controls to balance the system they might benefit from a pot upgrade to avoid loading up the contacts over time.
    Best amp I have found in 50 years of searching.
    No need for ME to look any further at this point although perhaps YOU have other ideas (low flea powered weird tubes etc etc---hey everybody likes something "different").
    But for dependable transistor A-A/B and low price per watt I think we have a winner.
    Just my two cents.
    Sugar Man, JayNYC, Pythonman and 2 others like this.
  19. mds

    mds Forum Resident Thread Starter

    Won't the First Watt be a little underpowered? Yes the Pass Amps are very expensive and this puts them in the fantasy lane, however I am hoping to pull together $6K to $7K for amp(s) and want a solid state amplifier that has the reputation of sounding very tube like. I am also trying to make this my last purchase since all my other components other than the amplifier has been upgraded to the point of complete satisfaction, so I am willing to spend a little more on the amplifier budget to make this the last purchase in completing my retirement dream audio set up.
    rischa likes this.
  20. mds

    mds Forum Resident Thread Starter

    I am picking up then that the heat generated is going to be much more noticeable than the heat generated from my current tube mono-blocks? For some reason I thought it would be close to each other in terms of btu output and the current amps are not an issue.

    It seems that people are hinting that the Pass Labs amps may give issue in terms of long term reliability due to the heat, or am I misunderstanding. I do not want an amplifier that will give me issue in five to ten years. I am hoping to make this my last purchase.
  21. mds

    mds Forum Resident Thread Starter

    Thanks for the suggestion. I did not think of CJ solid state amplifiers. I will give them consideration.
  22. mds

    mds Forum Resident Thread Starter

  23. mds

    mds Forum Resident Thread Starter

    The reviews all rave, so yes I tend to agree with your thought. I need to be open minded though since I am hoping to make this my last purchase in a long process of upgrading my entire system for its finally since I am just retired now and will be going on a much tighter budget.
  24. mds

    mds Forum Resident Thread Starter

    Agreed. My room is air conditioned and does have a large five foot opening into the other portion of my house so air flow is good. I really did not think a class A 30 watt or class AB 150 - 250 watt amplifier would be a summertime nightmare, but I will check this factor out in the immediate future. The other benefit is heating in the winter will be less expensive.
    SandAndGlass likes this.
  25. mds

    mds Forum Resident Thread Starter

    The power output is my concern and I am believing that the conservative class A 30 watts will be more power than my present mono-blocks since I run them in the Triode setting which gives my 38 watts of power. I also believe that the XA30.8 goes into AB power after the 30 watt class A limit and continues to throttle up for some additional power which should take care of those power robbing transients. I also was under the impression that Pass Labs class A amplifiers are very tube sounding. Do you agree with my thinking from your own experience with your amp?

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