SPL Phonitor X Review (DAC & Headphone Amp)

[Zensō]

1. RME ADI-2 Pro FS R
2. Schiit Jotunheim w/AK4490 DAC module
3. Benchmark HPA4

Martin

Has Schiit fixed that DAC module? It reviewed poorly in the Asgard 3.

 

[Martin]

Has Schiit fixed that DAC module? It reviewed poorly in the Asgard 3.

Ouch! that measures as poorly as the SPL... I guess I'll quit screwing around and just buy the RME.

Martin

 

[Helicopter]

Ouch! that measures as poorly as the SPL... I guess I'll quit screwing around and just buy the RME.

Martin

Yeah, I think it is most similar to the Modi 2... they really need to update the card.

 

[AndreaT]

A disorganic project with an overall poor product under attractive skin. Thank you for the excellent review!

 

[Zensō]

Ouch! that measures as poorly as the SPL... I guess I'll quit screwing around and just buy the RME.

Martin

That would be my advice. I did the same and that cured my upgraditis for good (or at least until RME offers a new version).

 

[Rottmannash]

This is a review and detailed measurements of the SPL Phonitor X DAC and balanced headphone amplifier. It was kindly purchased refurbished by a member and drop shipped to me. There was a label on the unit saying it was certified back in 2019. It has some fine scratches so it was definitely used.

I must say, I have been lusting after the Phonitor X from the first time I saw it at an audio show:

View attachment 117114

Aren't those VU meters gorgeous? What is that? You can't read the labels? I could not either! You literally need a flashlight or desk lamp to see them. Gray type on red just doesn't work from contrast point of view.

From the back you see that there is a ton of connectivity and functionality provided:
View attachment 117115

You can see the DAC/digital inputs on the right. Alas, in the 15 minutes I had before lost my patience, I could not get the USB port to work. Windows would recognize it but I could not get audio. It could be pilot error but I tried a lot of things and it would just not produce sound. So I did my DAC testing using Toslink input.

As regular readers know, my focus here is on engineering and performance. As such, I am ignoring the functionality and value of crossfeed, etc. that this unit has.

Claim to fame of the unit is that it uses discrete amplifiers in order to be able to operate at a very high voltage of ± 60 volts. They say that brings very high dynamic range which it can do. But let's find out if there is a down side to this...

SPL Phonitor X DAC Measurements
I must say it was a huge let down to be greeted to this level of performance from the DAC subsystem:
View attachment 117116

View attachment 117117

On top of that, max volume was only 2 volts instead of 4 volts. I thought maybe it does better at lower voltages but it does not:
View attachment 117118

Dynamic range was not as bad but still, not remotely what it should be in this class product:
View attachment 117119

There was a lot of interference in jitter test:
View attachment 117120

I went ahead and tested for jitter rejection by programming my Audio Precision analyzer to induce 1 nanosecond of jitter at 1 KHz. Sadly there was no rejection of it:

View attachment 117121

So best to use a clean digital source if you are going to use Toslink input.

Let's move on before we get more depressed over the DAC functionality...

SPL Phonitor X Pre-amplifier Measurements
For this test, I used XLR input and XLR Output in the back. I fed the unit 4 volt and adjusted the volume control for 4 volts. Was disappointed to see the VU meter peg to the max with no range switch to avoid that. Anyway, performance here was quite uplifting relative to the DAC:

View attachment 117122

Frequency response was excellent:
View attachment 117123

While not state of the art, signal to noise ratio was very good as well:
View attachment 117124

I was hoping to finish this set of tests on a high note but was not meant to be when I saw the poor crosstalk performance:
View attachment 117125

Oh well.

SPL Phonitor X Headphone Amp Measurements
DAC and pre-amp modes were appetizers. We are here for the main meal which is the performance of the headphone output. Given the competent pre-amp performance above, I expected the same here but it was not the case:

View attachment 117127

How did we lose 10 dB of performance at 600 ohm load relative to 200 kHz ohm that is used in pre-amp test? The reason for this will become clear shortly.

View attachment 117130

Signal to noise degraded as well:
View attachment 117128

50 millivolt SNR is very poor in general let alone for a device this expensive:
View attachment 117129

Let's see what it can do into 300 ohm load:

View attachment 117131

Good news is incredible amount of power if you allow a lot of distortion. Before flat out clipping we have whopping 3 watts of power!

Performance drops rapidly though when we go down to a 50 ohm load:

View attachment 117132

We have nothing to hang our hat on here. This amp simply doesn't low low impedance loads as we see in these series of sweeps:

View attachment 117133

Frequency response was also a bit more rolled off:
View attachment 117134

Channel matching is not good but there is a balance control which you can use to partially compensate for this:

View attachment 117135

SPL Phonitor X Listening Tests
As usual I started with my Drop Ether CX low impedance headphone. The Phonitor could drive it well but it was also easy to drive it into distortion.

I happened to have an HE-6 headphone on hand. So decided to test with that as well. Same thing happened here although distortion was a bit earlier. I tested the Topping A90 with it and had similar results.

Conclusions
SPL Phonitor X is a gorgeous looking unit with its pretty VU meters and nice industrial design. Alas, its DAC is a "phoned in design" that would be suitable to a $20 ebay special than anything performant. As a pre-amplifier it functions well. As a headphone amplifier though, it is only happy with very high impedance headphones. Its high voltage amplification helps a lot here. Below that, its performance is not competitive with amplifiers at much, much lower cost.

Given the high price, I just can't recommend the SPL Phonitor X. You can do so much better these days with modern designs. Get it if you like the looks, and have high impedance headphones.

------------
As always, questions, comments, recommendations, etc. are welcome.

Appreciate any donations using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/

What is its cost?

 

[amirm]

What is its cost?

$2,500.

 

[Rottmannash]

$2,500.

Holy *#%*! Thanks for saving some of us a bunch of money. ...but those pretty VU meters tho

 

[Martin]

What is its cost?

$2499 new / $1899 refurbished plus $300 for the DAC768xs module.

 

[Rottmannash]

$2499 new / $1899 refurbished plus $300 for the DAC768xs module.

Dude (couldn't resist), so sorry for your loss...

 

[YSC]

I am always tempted by their design and that it's german, plus the crossfeed circuit by them with decent specs for power. Luckily i never pulled the trigger on them with their price... this one really looks like a huge letdown

 

[Takanaka]

Wow I actually considered this bad boy a few months ago, seems I dodged a major bullet there.

 

[Jimbob54]

1. RME ADI-2 Pro FS R
2. Schiit Jotunheim w/AK4490 DAC module
3. Benchmark HPA4

Martin

Why the RME pro rather than the ADI 2 DAC? Fancy having an ADC?

 

[respice finem]

$2499 new / $1899 refurbished plus $300 for the DAC768xs module.

Factory refurbished, or is there a remote possibility of a "botched job"?

 

[Martin]

Factory refurbished, or is there a remote possibility of a "botched job"?

It was listed as manufacturer refurbished. The USB input does not work so it was obviously botched and not tested after "refurbishment." It is clearly defective. I opened a ticket with SPL and initiated a return with the dealer.

 

[Martin]

Dude (couldn't resist), so sorry for your loss...

"I'm the Dude, so that's what you call me. That or, uh, His Dudeness, or, uh, Duder, or El Duderino, if you're not into the whole brevity thing."

 

[YSC]

"I'm the Dude, so that's what you call me. That or, uh, His Dudeness, or, uh, Duder, or El Duderino, if you're not into the whole brevity thing."

Anyway with the headphone and pre amp it’s still half decent and usable

 

[Deolum]

Oh, why oh why they put switches underneath a box when they have so much room on the face panel? Anyway, I will look to see what it is set to.

Did you find it out?

Because it is balanced input and output which is all you should care about. How it works internally is not anything we should care about if it measures well.

Can you or anyone else who upvoted this elaborate a bit more on this? Because it's exactly contrary to what i know so i'm curious why using balanced ports in an unbalanced device makes sense.

 

[KenG]

"I'm the Dude, so that's what you call me. That or, uh, His Dudeness, or, uh, Duder, or El Duderino, if you're not into the whole brevity thing."

Whenever I read your posts, it's always with a Jeffrey Lebowski voice.
The SPL Phonitor really tied the room together, man.

 

[shal]

I took my SPL 2Control out of my system due to poor noise performance. My monitors would never go into standby, it was so bad. It's off to be refurbished now but I don't see it myself using it again. I did like the crossfeed a lot, though.

I can't agree on SPL build quality. This is one of the only products I've ever had break on me. A couple bad pots, the volume knob refused to stay tight on the pot, and the front lighting crapped out a couple years ago.

It is very, very pretty though.

I bought a used SPL 2Control and same thing, I sell it quickly because, when it was power on it send big "pop" to the amplifier
For a Control box directly connected on power speacher or power amplifier is mandatory to does not produce this kind of noise

Fortunately, I bougth at a very good price, so no difficulty to sell at the same price