Pass Labs XA25 vs First Watt F7- The two newest Nelson Pass amplifiers go head-to-head

Nelson Pass releases two low-powered amps, and jelt2359 is ready with his trusty Hifiman HE6


The Sound

The F7 pulls you into its orbit immediately. It is vast. It transports you to endless outer space, and leaves you there to contemplate the notion of infinity. The sound is expansive, open, and joyful. But there are also downsides to this approach. You are forever in the orbit of the F7- and cannot get any closer. Like an iMAX experience, it’s a technicolour marvel; it’s a feat of engineering; but it’s on a screen, doomed to remain forever in front of you. Unlike Patrick Swayze in Ghost, the music never reaches out and puts you in its phantom embrace.

In contrast the XA25 stretches out its hand, and takes you on a journey. You will hear the venue as the music bounces back and forth from every inch of its four walls. Cue up a performance like Cirque du Soleil live in Vegas, and you’ll hear the corners of the auditorium, and every nook and cranny of the performing space. You’ll feel yourself there, transported in living colour as the show envelops and overwhelms you. It’s outside; it’s all around; and it’s even playing through you.

Again, though- it’s not all a free lunch. When the venue is not so impressive to begin with (for example, erm, a recording studio), the XA25 will sound comparatively flat and constrained. In these situations the F7 really shines, taking even the most mundane of settings and transforming it into an experience to be beheld. With the F7, you feel you are being whisked away on a magic carpet ride. A gorgeously live al fresco performance under the stars, you will never hear the reflections on the walls… But who wants walls to begin with!

What the XA25 manages- having the music unfold itself through you- is no easy task. You need to feel the rhythm of the performance. You need to be moved with a sense of urgency. Both of these are present in spades with the XA25. The music is dynamic, hard-hitting, and soul-searching. It is animalistic and instinctual. Nowhere is this more obvious than the bass. The F7 was always adequate in the bass, a solid B+, but bass lovers need not apply. The XA25 hits harder, deeper, and with more shades of black and grey. You see, hear and feel every low note in lush glory. On the other hand the F7 bass is a bit like a chocolate fondue. It’s always there, flowing like an endless fountain spring, so you will have no cause for complaints. But the chocolate cannot be too thick or rich, lest it slows the flow or starts to clog up. Instead it’s fast, light and caffeine-free.

The focus of the F7 in general is always on effortlessness, to a fault. The mids on the F7 are lean. They’re clean. They’re fast, and subtle. The XA25, in contrast, is velvety. It’s smooth, and it’s organic. The midrange notes it produces are rich, beautifully self-contained, and tungsten like a filament. The notes brim with desire on the XA25, whereas on the F7 they’re flat and thinner, with detail seemingly pushed aside to lighten the load on the music, and gaining that last ounce in raw speed. The XA25 is a sprinter, the F7 a marathon runner.

All this also means that the XA25 is bad at being a supporting actor. Its music calls to you. It has a distinct attention-sucking type of effect that makes for very bad background music. In fact, I had to turn off the XA25 in order to put pen to paper on this review, because I kept getting distracted by florescent musical notes sparkling their way into my ears. On the other hand the F7 is perfect for background. It’s always easy and never skips a beat, and when you want to take a break and relax a tad bit more, you can always sip on it and like a cup of soothing hot tea, it shows itself to be light, expansive and full of possibilities.

It’s the Fourth of July, and fireworks are in the sky. It’s explosive, it’s a treat, but it’s distant. You can see it, but you can’t feel it. It’s a beautiful experience but primarily a visual, not visceral, one. It will never engulf you. If this is the sort of contemplative experience that appeals to you, it is hard to say no to the First Watt F7. For that reason, I will be keeping this amp as well. I have rarely heard amps create as visual an experience as this, and its unique qualities are certainly to be lauded. The XA25, however, is richer, incandescent, punchier, and more dynamic. There’s something effortless and fast about the F7 that the XA25 cannot match, but the latter amp feels more organic, more emotional, and in the way it explores every venue of every performance, more true.

Yin, or yang. Which do you prefer? Me, I’ll be keeping both.



Both these new Nelson Pass amps are outstanding performers. The F7 and XA25 are both quiet enough, with low enough noise floors, to be used with headphones without any hiss. The XA25 is the better amp, but the pair are so different that fans of one may not enjoy the other.



Picture of jelt2359


When jelt2359's Shure earphones stopped working ten years ago he was forced, kicking and screaming, to replace them. He ended up with more than 20 new IEMs. Oops! jelt2359 flies to a different city almost every week for work, and is always looking for the perfect audio setup to bring along.


7 Responses

  1. Hi, wonderful review. I may pull the plug on the XA25 since I really want to listen to a Pass amp with my Susvaras. What other pre amps have you found that contribute to a relatively noise free listening?

  2. Yes, I must admit that with the EAR V12 amp, I admire it as much for its looks; as its sound! It is absolutely a work of art!

  3. That is super helpful! Many many thanks….

    EAR V12, great choice, I love EAR and it Jaguar engine like design:)

    All the best

  4. Yes, those other amps may be good options as well (F1J/F2J), although I have personally not tried them. Another thing to bear in mind would be the gain, the less the preamp has to attenuate the better. To this end the F7 has 14dB, the XA25 20dB, the XA30.8 has 26dB.

    I you’re really going to go down this route it’s probably worth picking up a Hifiman HE6. The Audezes are great options, very different presentation (more intimate, warm), but the HE6 really takes well to additional power, and is very insensitive so has less hiss on speaker amps than any of my other headphones. In this regard it’s simply the best headphone out there for speaker amp use. Unfortunately it’s been discontinued so you’ll need to look for a used unit.

    Apart from my First Watt F7, Pass Labs XA25, and Hegel H20, I also have two tube speaker amps- an Ear Yoshino V12, and an Almarro A318B.

  5. Thank you for the Reply! I pair the XA 30.8 with an XP 20 preamp so I guess it is not a preamp issue – which btw has a fine level adjustments very handy with the headphones – but as you are interestingly pointing out it is probabky an issue of the output noise of the XA 30.8 and I understand the better we are below 100 UV the better it is. I was just looking at some FirstWatt incanations which have 30 UV output maybe they sound fantastic with headphones….
    If I may and if you can, which amps are you currently rolling in your full headphones set up?
    Again thanks and take care

  6. Thanks for the kind words! The XA30.8 has more than four times the noise floor of the XA25 (200uV for the former, less than 50uV for the latter), and more than twice vs the F7 (100uV for the First Watt), so it’s not surprising you’re hearing more noise than I did. In general, headphones are much more sensitive to noise, and some amps end up sounding really noisy on my setup even though reviews of the same component say the opposite. There’s no way around this, unfortunately. One thing I have found helped, though- the quality of the preamp. On my Hegel H20, for example, with some preamps I hear it as really noisy, whereas with my Chord Dave’s digital pre I find it pitch black.

    I don’t think the problem is your choice of headphones. I own the LCD2 and LCD3 as well, and have used them with speaker amps to great effect as well. In conclusion: at this point, I own five speaker amps, and have nary a pair of speakers to my name. Some are noisier, some are not; and the preamp matters.

    Hope this helps!

  7. Hi, thanks first of all. I found your review very interesting. I do have an XA 30.8 and since my time to use it with speakers is diminishing (as I listen at late night hours) and I’m a big heandphones fan, I’m trying too to use my XA 30.8 as the the main amp to power up my headphones. I paired it directly via its speaker binding posts to the headphone cable using a tail adaptor (banana to XLR four pin female) to Audeze LCD 2 (pre fazor) and LCD 3 Fazor, which are quite power hungry, and though the sound/scale/dynamics were excellent the level of noise floor is simply to much. How di you made the trick? Aren’t the Audeze a good match?
    Thanks for your comments

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