SPL Phonitor X DAC/AMP - Official Thread



Very comprehensive review. I think you should have top notch headphone in order to benefit this DAC/AMP.
Build quality is very important and as per review it is so quality.


@Torq, do you have compared the SE out to the balanced out? SE seems to measure better according to the SPL side, htough the difference is most likely not audible.
I’d also be curious about listening levels, if you use the RME with attentuation 0 it’s pretty hot and with the additional dbs of the Phonitor balanced its gets pretty loud from my experience. Do you use any additional attentuation?

I’m planning on getting a custom cable made for the HD650 and am debating if I use SE or balanced termination.


In general, the balanced version of an otherwise identical single-ended amp circuit will exhibit about 6 dB more noise (and consequently about 6 dB less dynamic range). Which is what you’ll see in the specs here. In real terms, this is no directly audible, but what is audible - if you have material that can demonstrate it, is a very slight improvement in image stability, detail and micro-dynamic resolution via the balanced output.

No, I am not using any additional attenuation.

The SPL Phonitor x has a huge amount of headroom on it’s inputs (up to +32.5 dBu). Even feeding it from the RME ADI-2 DAC at its highest output reference level (+19 dBu) at 0 dB attenuation (which gives it its best dynamic range/noise performance), you’ve still got a lot of headroom. So the input side is fine.

And in terms of the resultant output, there’s enough travel on the dial on the Phonitor x to give you usefully granular control and no channel balance issues (not that there were any even at super-low volume), even at normal listening levels (about 80 dB).

Bear in mind, you have more than way to control the output level of the RME-ADI 2 DAC. First is the output reference level, which covers a range from -5 dBu to + 13 dBu in single-ended output and +1 dBu to +19 dBu via the XLR outputs. The second is the digital volume control attenuation.

If you set the digital volume control (which is the level displayed on the unit’s screen) to 0 dB, and your reference output level is at -5 dBu then you’ll obviously have more room to move on the Phonitor x’s dial, even without digital attenuation changing the signal.

I’d go with balanced, even if only because a) it’s easy to then add an adapter if you want to go back to single-ended (which you can’t do otherwise) and b) because it’s a safer bet with the Phonitor x.


I’ll get a balanced cable then.
I’m using “auto ref lev” mostly, haven’t tried the other options yet. The RME has so many options is sometimes makes me dizzy.
Thanks for your help, again!


SPL recently announced a bit of the update to their line-up at Munich in May including the new SPL Phonitor XE https://spl.audio/professional-fidelity/phonitor-xe/?lang=en

Looks like an interesting mix of the E and the X!


That is very cool, I now need to research this lol


This looks very interesting. I can’t wait to see the reviews!


It’ll be very interesting to see how much of the XE is just a re-arrangement/prioritization of features vs. any audible improvement in its abilities as an amplifier.

I’m not sure how much use I have for additional rear-mounted headphone connections (the cable has to come around to the front anyway), vs. the pre-amp outputs on the X, but I do like the idea of being able to switch the VU meter attenuation from the front-panel (DIP switches are a PITA).

Aesthetically I think I prefer the slight, extra, fussiness on the X over the XE … but that might change in person.

The new DAC module should be interesting though, and is hopefully a good step froward from the competent, but uninspiring DAC192 offered for the current X.

Definitely something I want to audition!


I really enjoyed your review of the Phonitor X and I am attempting to decide between the purchase of a Phonitor X/XE and an iFi iCan Pro. From various reviews, including yours, I have the impression that both amps are extremely capable, regardless of the headphones one uses. As such, am I correct to assume that the major differences between the two amps has to do with the features offered, in particular the tube + option on the iCan vs the Matrix/Corssfeed controls on the Phonitor? If so, which would you say is more useful in terms of adding pleasure to the listening experience (my primary headphone is the Focal Clear)?


The Pro iCAN is going to give you the broadest array of different sound/signature possibilities, between its bass-enhancement control, crossfeed, and its tube/tube+ modes. As such it probably has the best overall potential for adding to any given listening experience.

If, however, your goal is the closest reproduction of the source, with the greatest transparency, the Phonitor X is definitely the better amplifier (it’s remains the best solid-state headphone amplifier I’ve heard, and for me bests the Pro iCAN regardless of what mode you run it in).

The Focal Clear are resolving enough to let you hear the difference between them, even when both are run in solid-state mode.

At the end of the day, they’re not so far apart that it’d be unreasonable to choose purely based on which features were of most interest and/or on price. I’ve chosen to keep both - mostly because at home I can have both the Phonitor X and my big tube amp, and in the office the Pro iCAN lets me have most of the best of both worlds, in a single compact unit.


Thanks for taking the time to respond. I would have no use for the bass boost as I either use a Schiit Loki or the Roon EQ and I was not impressed by the 3D (crossfeed) feature on the iCan SE that I once had but perhaps it is better implemented on the Pro. I am very intrigued by the Crossfeed function of the Phonitor since you, as well as others, say it works quite well. I also like the idea of adding a smell amount of 2nd harmonic distortion via a tube sage but the fact that you feel the Phonitor sounds better than the iCan regardless of which mode is engaged is a a convincing endorsement.

Have you heard the Pass Labs HPA-1? I ask because it is another headphone amp that some feel (Bob Katz for example) is one of the best SS amps around and I was wondering how it compares to the Phonitor X.

Considering how transparent and revealing of the source the Phonitor is, I assume that upgrading from a Schiit Modi Multibit to at least a Gungnir or RME ADI-2 DAC would yield impressive results and might even be necessary.


Let’s see …

For sure, all of the amps we’re taking about here warrant being fed by something more capable than the Modi Multibit (which is a lovely little DAC, but it’s no ADI-2 DAC or Gungnir etc).

If you’re considering the RME ADI-2 DAC, you might want to give it a try feeding the Clear directly from that before you spend the money on amplifier. An external amplifier of the level we’re talking about will definitely be better, but you may find the native output in the Clear to be as good as you need/want (they’re very easy to drive and due to their very dynamic nature don’t seem to be as affected by the slight dynamic compression the ADI-2 DAC’s native headphone output can exhibit).

For me, I would probably lean towards the RME unit as a DAC to feed the Phonitor X.

I would remove the Loki from the chain and use the RME’s EQ as it is more precise, despite being digital in nature.

And if you wanted to have some tube-flavor from time to time, then as long as the DAC you choose has dual outputs, you could do something like run the XLR outs from it to the XLR inputs on the Phonitor, and then run the RCA outs via something like the iFi iTube 2 and back into the amp. Switching inputs on the amp would then let you use the different tube options on the iTube 2.

I’ve heard the HPA-1, very briefly, but have not done a direct comparison between it and the Phonitor X. Using a Chord DAVE as the source, and comparing to its direct headphone output, the SPL unit is, so far, the only one I felt wasn’t losing anything and was simply bringing enough grunt to the table to drive headphones that DAVE isn’t quite powerful enough to get the best from.

It’s entirely possible with more time with an HPA-1 I would find the same is true there, but that wasn’t the immediate impression I had when I, again briefly, got to try one. And to be fair the situation wasn’t one in which that was a test I really could make with any degree of reliability. That’s something I’d definitely be game to try again properly, given the opportunity. But at least for me, the $1,000 price difference, and the lack of a few features I need in a solid-state headphone amplifier, I’m likely to stick with the SPL unit unless the HPA-1 was discernible (as an improvement) in a blind(ish) comparison.


It’s probably also worth noting that the majority of my at-home headphone listening, when its simply for pleasure, is either via my Woo WA234 Mk2 MONO or, when I want solid-state and the headphones I’m using at the time don’t require tons of power, straight out of my Chord DAVE.

The Phonitor X mostly comes into play for reviews, or when I want solid-state and am running things like my LCD-4 or the Abyss AB-1266 Phi CC, neither of which I find are at the best straight out of DAVE.


I’m between the Pro iCan and Phonitor X as well, but I’m unsure if I want to commit to balanced cables. How do they compare single-ended?


It’ll somewhat depend on your headphones and source, but on transparency and resolution grounds I would still give a nod to the Phonitor X.

It’s still pretty close though and, again, it’s hard to go wrong with either - and perfectly reasonable to buy based on price or desired features.

Balanced cables don’t have to be much of a commitment. A set of decent 3-pin XLR interconnects can be had for between $40 and $100, depending on length. And depending on the headphones in use balanced cables can usually be found for $60-$100 (unless you have HD800 or Utopia).

The benefit from getting the completely separate left/right channel connections is the most important one and dwarfs any concerns about fancy metallurgy and pretty braiding.


Sorry for taking so long to respond. Thanks once again for taking the time to provide advice. It is well appreciated.

I have decided to order the Phonitor XE as I would find a second balanced headphone out more useful than a pre out, even if it is on the back (it appears that they just replaced the pre outs on the back with headphone outs) . As well, the XE is less expensive than the X. The idea of adding an iFi iTube 2 to the chain is interesting. I had a Schiit Saga connected to my Gilmore Lite MK2 and it very slightly opened things up and added a nice little lift to the sound. I imagine the iTube would be more impactful. While being quite a bit more expensive than the iCan Pro I wonder how the iFi tube buffer in front of the Phonitor would compare to the iCan in tube mode? That would be an interesting comparison to read about if anyone has done it.

I guess a DAC with a tube section could also be interesting, like a Lampizator but now we’re talking very big bucks. Out of curiosity, do you prefer the RME to the Yggdrasil A2 when paired with the Phonitor X?



Nice to see that the Phonitor XE is now shipping! Interesting to see it comes in $500 less expensive than the “X” as well. Now I just have to wonder if they’ll be able to offer the new DAC module for the “X” model (for new customers) or whether it’ll only work on the “XE” (I imagine the board has had some layout revisions).

The iFi iTube 2 has a more audible effect on the sound than using a Saga as a buffer (Saga is very transparent, which is what you really want in a pre-amp), at least with the standard tube. Whether that’s good or bad is going to be down to the individual listener and their preferences.

I’ve heard (and owned) DACs with tubes in them … and the outcome of that has been a promise to myself to keep the tubes either in a buffer stage or the amplifier and leave them out of the DAC. The MHDT Labs line-up uses them to good effect, and is pretty affordable (I had a Stockholm V2 for a while in my bed-side rig), but otherwise tubes in DACs haven’t worked out so well for me.

Do I prefer RME ADI-2 DAC vs. Yggdrasil A2 into SPL Phonitor X?

No … I personally prefer the Yggdrasil A2 over the RME unit - and that’s true pretty much regardless of what it is feeding. Though in general I do not have the Yggdrasil A2 in that system. My SPL Phonitor X is currently getting a balanced feed from an ADI-2 DAC, and a single-ended feed from my Chord DAVE (the balanced output from which feeds my big Woo tube amp).



Do you know anything at all about the new SPL DAC other than what is on their website, which Isn’t much.


No, just what they’ve posted.

Hopefully they’ll use a different USB receiver chipset (in addition to the other changes) so that switching sample rates on the fly under macOS works, though.


I finally received my Phonitor but because of the delay in delivery time for the XE my local dealer offered me an X for the same price as the XE.

It is as you so thoroughly described! I am very impressed, especially with how well extended and detailed the upper registers are while not being harsh or unnatural sounding as so many SS amps that are not rolled off tend to be.

You mention that you your Phonitor X is currently getting a balanced feed from an ADI-2 DAC, and a single-ended feed from a Chord DAVE. Have you tried feeding the Phonitor’s XLR and RCA inputs from the same DAC and compared between the two inputs? The reason I ask is that I connected my DAC’s SE and Balanced outputs to the Phonitor and when I switch back and forth there is quite a noticeable difference, with the XLR input sounding rather compressed in comparison.

In the manual it is stated: “Signals at analog RCA input, will be amplified from HiFi level to studio level. The sources are then equal in level when you switch between XLR and RCA (provided that a studio signal is present at the XLR input).” My DAC’s RCA output level is 2.05 Vrms while the balanced (XLR) output level is 4.1 Vrms. I am not quite sure what SPL means by “studio level” but do you think the reason for the difference between the two inputs has to do with the fact that the RCA input signal is being amplified beyond the 4.1Vrms of the balanced signal?