SPL Phonitor X DAC/AMP - Official Thread

Sort of …

I’ve done it with two separate ADI-2 DACs, one via RCA and one via XLR - something I chose to do because some sources (and/or amps) don’t always behave well when you make multiple connections between them. Additionally some sources don’t behave well if you connect more than one output at a time*.

While it is more work to compare, you should try listening to the single-ended output from your DAC feeding the single-ended input on the Phonitor X without the XLRs connected, and then swap the connections and try the balanced side (without the RCAs connected). This will ensure you’re not running into funky issues with the source and/or interactions with multiple connections to the same amp from the same source.

What DAC are you using, by the way?

With the Phonitor X, while the balanced and single-ended paths measure differently, I can’t reliably tell the difference in listening and generally use the balanced input and output on it as my primary connections.

(In case you’re wondering why I don’t use the balanced output from my DAVE into the Phonitor, it’s because I have that feeding my big tube amp).

*For example, my original Yggdrasil would not emit any sound if I had the single-ended output connected to my old WA5-LE and the balanced to an iFi Pro iCAN unless the Pro iCAN was switched on.


Thanks for taking the time to respond. I will give it a try.

I opened a ticket with SPL support and asked them what they think as well. It will be interesting to see how they respond. I assume the reason they amplify the SE input from “hifi to studio level” is so that one can switch between sources without having to volume adjust.

I did try connecting another similar sounding DAC to one of the inputs and the results were the same so I don’t think it’s the DAC that doesn’t like 2 outputs being used at the same time.

I will do some more testing.


So, Phonitor e is Phonitor x without the pre-amp, crossfeed and VU meters, and Phonitor xe is Phonitor x without the pre-amp?

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I am not sure about the Phonitor e but from what has been written elsewhere I think the Phonitor xe is the phonitor x without pre-amp but with additional headphone outputs on the back instead and VU meter attenuation switching on the front panel vs the dip switches on the x. The e offers crossfeed/matrix control but the speaker angle is fixed to 30 degrees with only 2 settings for crossfeed adjustment.


I attenuated the VU meters using the dip switches and connected my DACs using one output/input at a time as you suggested. The DACs I am currently using are the Schiit Modi Multibit and the Audiolab 8200 CD player, which has both balanced and SE outputs.

There is a consistent difference of about 4 db when switching between the SE input (peaks at 0 db) and Balanced input (peaks at -3db) on the Phonitor X, the SE input being 4db hotter, whether using the Schiit or Audiolab. This measured difference is quite audible to me, so I find it interesting that you wrote, " With the Phonitor X, while the balanced and single-ended paths measure differently, I can’t reliably tell the difference in listening".

I wrote SPL and this was part of their response, “I can not believe that you have a compressed or distorted signal, the maximum input level of the Phonitor is round about +32,8 dBu because of the 120V operation voltage … so compression or distortion at the input is not possible with usual equipment.”

While I am not quite sure I hear distortion using the SE inputs, it does sound hot (using both the Schiit and Audiolab) and there is definitely more headroom using the balanced inputs, which is odd considering that the Phonitor X does not have balanced circuitry.

I would appreciate having your thoughts on this, if you have time, before I consider taking the unit in for testing.

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Unless you’ve got measured/calibrated outputs feeding the input of the Phonitor X, I’m not sure how you’re deriving those numbers (I suppose a constant pink-noise-source at a known level would let you just compare off the meters). The Schiit DAC doesn’t have a balanced output, and the outputs on the Audiolab for SE/Balanced are a) going to be different and b) not necessarily referenced to the same level as the Schiit DAC for single-ended anyway.

So I’m missing something there …

My listening tests are done level-matched.

Qualitative listening comparisons are not very useful/reliable otherwise.

In the test I did with a pair of RME ADI-2 DACs, one single-ended, one-balanced, level matching was achieved by adjusting the output level on the DACs - as that facilitates switching inputs via the switch on the Phonitor X without then having to measure and trim the listening level on the amp. And in that situation I hear no qualitative difference between SE and BAL inputs on the X at all.

My reference to differences in measurements is to the higher noise/lower DR quoted for the balanced headphone output - which are real but below audible thresholds.


My interpretation of the difference in input levels is merely based on how I am eyeballing the VU meters. I have not calibrated/measured outputs feeding the inputs of the Phonitor X, nor was I using a constant pink noise source.

Using the same piece of music, VU meter readings peak at the -3db mark on the VU meters when using the balanced output of the Audiolab while peaking at the 0db mark on the VU meters while using both the Audiolab and Schiit SE outputs. While I realize that an attempt at qualitative listening without level matching is futile, my concern is with how the RCA input signal is being amplified to level match the XLR input signal and whether it might be adding too much gain to the signal.

Based on the manufacturer’s technical specs, Schiit and Audiolab output a maximum of 2 vrms and 2.1 vrms respectively at 0.1db from their SE outputs while the balanced output level of the Audiolab is 4.1 vrms at 0.1db. Yet audibly the SE input signal is noticeably louder than the balanced signal, which seems to correspond with how the input signals measure on the VU meters.

I get the sense that the SE input signal is too hot and on the borderline of clipping but as you said, unless I level match it is very difficult to tell. And, according to SPL, distortion would be impossible because “the maximum input level of the Phonitor is round about +32,8 dBu.”

Well, I’m not sure what’s happening in your particular case.

What I can tell you, for mine, is that feeding it a single-ended signal even at +13 dBu (about 9.78vpp), I get no audible distortion nor any apparent compression either directly or compared to an XLR input referenced from anywhere from +6 dBu all the way up to +19 dBu (~20vpp).

It most definitely isn’t exhibiting any signs of clipping even at those high input levels.

Using one RME ADI-2 DAC, and adjusting its output levels when switching between single-ended and balanced connections, level-matching, and listening also shows no audible difference.

I suppose it is possible (though not necessarily likely) that the extreme transparency and dynamic resolution of the Phonitor X is exposing other things in your sources, or their outputs, that you may not have heard before. It is certainly capable of revealing the differences, for example, in the level of background blackness and resolution between a Modi 3, an original Modi MB and the most recent builds of the Modi MB.

It also would not be the first situation I’d heard of where switching out an amp (or how it was connected) revealed aspects of upstream gear that suddenly were not to the listener’s liking. The trick of which is then generally figuring out whether the amp is doing something wrong, or if it’s just letting you hear what was always there but was masked at some level.

Regardless, if you’re not sure about it, or happy with it, I’d get it checked.


Thanks again for responding.

I must admit, before acquiring the Phonitor X I was not able to confidently differentiate between my two DACs (differences were always very subtle) and I have owned the Violectric V280, the Massdrop THX 789, the HeadAmp Gilmore Lite MKII, the Woo Audio Wa6 SE, the iFi iCan SE and the Burston Soloist SL MKII, all very competent amplifiers but other than the Violectric, nowhere near in the same league as the Phonitor X. For this reason I never gave much thought or priority to upgrading my DACs.

While perhaps more suitable for another thread, I am now giving this some serious thought but DACs are very difficult to properly demo, least of all because most dealers do not perceive a great demand for higher end DACs and as such do not carry much of a selection. My impression is that in terms of a real audible improvement, it would not be worth upgrading to something like the Artist R-2R but to make a leap up to a Schiit Yggdrasil A2 or something in that league. It’s a lot of money to spend though, without being able to hear it first.


While this may be the case for some, the real reason most dealers don’t carry higher-end DACs (especially online deealers) is that most companies in the DAC/AMP realm are direct to consumer or only allow Brick & Mortar sales. Since online retail is growing by 13% every year, hopefully we will see a shift in the next couple of years.

The other issue is that a lot of high-end DAC / Amp companies are located on another continent and either don’t have North American distribution or their North American distribution is not very competent. So then it comes down the dealer wanting to deal with warranty issues where they have to ship back to Europe and a repair process that can take up to 6 months which isn’t pleasant for the dealer or the customer.

Anyways, I’ve been really enjoying the Phonitor X discussion happening! Lots of great information being exchanged here!


I recently visited a local audio dealer and when I brought up direct to consumer manufacturers the owner of the store went into a rage. His face went red, he foamed at the mouth and used every profanity imaginable. I though he was going to have a cardiac arrest.

While it is very useful to be able to go to a local dealer and demo a piece of gear, unfortunately there are few dealers whom I did not feel were feeding me BS; marketing hype that they did not fully understand, akin to my experiences purchasing an automobile. And while the direct to consumer model removes the fast talking sales person out of the experience, in order to demo one often has to deal with restocking fees or if living in another country, import duties and even sales taxes charged by customs that are not refunded if the item is returned, as well as shipping fees, etc.

It will be interesting to see how the move to online, direct or indirect goes. Look at what’s happening with online car sales. . . .

How are you enjoying the Phonitor X?

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https://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Dvehicles&field-keywords= Yes Amazon has hopped back on the Online Vehicle Market so that is going to be an interesting market in the future. Can’t imagine when someone purchases an Audio R8 from a vendor and then utilizes Amazon’s no questions asked return policy and returns a bag of rocks instead which they still get a full reimbursement for from the FBA employee.

The Phonitor X is both @andrew and I’s favourite headphone amplifier. We got one last year as a demo with the intention of sending it back after a month and yet it is still in our office, sitting on my desk. The absolute silence with the noise floor is amazing and it has more than enough juice for any headphones we’ve tested with it.

Granted, we have not gone as deep with it as you or @Torq in regards to the DIP switches, measurements and such. But we did have the Naim DAC-V1 in the office before the Phonitor X and I will say I much prefer the Phonitor X.


Dealers are definitely a mixed bunch. Some just want to soak up their 30-45% margin for doing little more than ordering you a unit that they don’t keep in stock in the first place. Others will loan you gear, or come setup entire at-home trials, without any fuss at all. Though this latter behavior is usually the product of having developed a proper relationship with them, usually over some meaningful period of time and actual purchases.

Removing the typical “local dealer” from the equation will typically do more than just remove the sales pitch/person from the deal though, as direct-to-consumer also removes their markup. Which is one reason why D2C units like the Yggdrasil are so hard to beat at anything like a competitive price when faced with dealer-stocked units.

Still the best way to hear a lot of the gear discussed on forums like this is via local meets. Stuff will show up in those that’ll never be available for loan and might not even commonly be seen at major shows. And having local friends in the hobby, even if not as local as one might like, makes a big difference in terms of what you can get your ears on.

Anyway …

If I was setting out on a search for a DAC worthy of the Phonitor X, I’d be starting to look around the levels of things like the RME ADI-2 DAC, Schiit Gungnir (DS or Multibit, though my personal preference is for the latter), Soekris dac1421 (or 1541), Chord Qutest, and work up from there.

Buying used, while a bit of hassle, is another way to sample DACs, at length, without much risk of loss. Most of the units I’ve listed above can be found used without much hassle and will then resell for little pretty much what you paid for them.


“Still the best way to hear a lot of the gear discussed on forums like this is via local meets.”

Unfortunately there aren’t any local meets that I know of where i live - Montreal, Canada. The only chance I have at listening to gear is at the annual audio show in the spring but conditions for auditioning gear are far from ideal.

“Most of the units I’ve listed above can be found used without much hassle and will then resell for little pretty much what you paid for them.”

Yes, most used Schiit Gungnirs
and especially Yggdrails I have seen are rarely discounted for more than 30% off retail, even the older versions. I don’t see many
Yggdrails on the used market though.

If that’s the case, it seems like a perfect opportunity to try and start something. It’s hard to imagine that you’re the only music-loving, headphone-using, soul in Montreal.

It’s not about how much cheaper they are vs. retail - it’s about the fact that once they’re used, they’re used. If a used Gungnir MB sells for $1,000 (instead of $1,295), and you pay $1,000, then if you don’t like it and want to sell it you’ll still be able to get $1,000 for it.


My point was that compared to other DACs, Gungnirs and Yggdrasils seem to retain their value better, especially Yggdrasils. From what I have seen, for most other products, once they have had more than one owner their resale value depreciates faster.

I meant to write, “more than one previous owner.”

I’m using a Phonitor e (+HD650 balanced) and am also debating the DAC question. Right now I’m using the RME ADI 2 DAC, single ended with ref level +1 (0,87 V RMS). This gives me a comfortable range between 8 and 11 on the amp volume control. I can go up to rev level +7 (1,73 V RMS) for music with a very high dynamic range.
I’m using bitperfect output without any DSP or replay gain etc.

What puzzles is how people use the Gumby (or simillar) with balanced output (that’s 4 V RMS) into the Phonitor using a HD650 with balanced headphone out and have any range with the volume control left. Do you handle this without any further attentuation?

Now I find the RME unit doesn’t deliver a very engaging experience, it’s good but not lots of fun.
What would be better, getting a new Bifrost Multibit and use it singel ended without further attentuation or get a Grungnir Multibit and use it single ended or using the Grungnir balanced with attentuation (passive or active preamp, replay gain preamp etc)?

According to the Phonitor e manual, " If you connect a HiFi audio device (e.g. a CD player) to the analog RCA input, you can amplifiy the signal from HiFi level to studio level with DIP switch 2. 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). DIP switch 2: ON = The RCA input is boosted from -10 dBV (HiFi level) to 0 dBu (studio level)"

I wish this option was available on the Phonitor X because the RCA input is always amplified to “studio level” (4VRMS). So in my situation, I find I have less volume range when using RCA inputs as the signal seems to be amplified to one that is greater than that of the XLR input fed from my Audiolab 8200CD at 4.1Vrms. Fed from my Modi Multibit (RCA, 2Vrms) I also find the signal to be hotter then fed from the XLR output of my Audiolab.

I think it would have been more useful if SPL offered input attenuation on its Phonitors than the meter attenuation they offer on the Phonitor X and XE. In your case, I would stick to the RCA inputs as with those at least you have a choice to amplify the signal or not. As well, I don’t think the Phonitors use balanced circuitry. That said, I do not know if the Gungnir Multibit performs differently whether using balanced or SE outputs. @Torq might be able to provide guidance on this.

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damn it… I need to leave this thread… makes me want a SPL Phonitor X/XE even more… :money_mouth_face::frowning_face::dizzy_face: