[Dreadhead]

[size=large]Review of the SPL Phonitor[/size]

Introduction:
Last year I started to read about this new amplifier from SPL with its exotic crossfeed and I had to hear it. SPL America generously agreed to send me a Phonitor sample for review on Head-Fi and in short I am extremely impressed with the amplifier.

On top of that the Phonitor has an amazing fully adjustable crossfeed circuitry that does an amazingly effective job at recreating a speaker setup. That’s the real purpose this amplifier: to replace speakers in the monitoring environment for professional mastering and recording engineers and my understanding is that it has been a hit among that crowd and I understand why!

Amplifier Features:
1 pair of XLR inputs
1 pair of Loop outputs
Single ¼” Headphone Jack
120 V Peak to Peak Output Voltage Swing (HUGE)
Fully adjustable crossfeed
Other monitoring features (see manual on the SPL Website)

Headphones Used: Sennheiser HD650, Denon AH-D5000, Sony MDR-SA5000

Similar Products Used: Headamp GS-X, Balanced Beta22

Sources: Bel Canto DAC3

Music:
O Brother Where Are Thou? Soundtrack, Various
In Rainbows, Radiohead
In Between Dreams, Jack Johnson
A Rush of Blood to The Head, Coldplay
Kid A, Radiohead

Fit an Finish:
The Phonitor is a utilitarian looking amplifier but SPL knows how to make utilitarian look and feel luxurious because everything about this amp is solid and professional. It’s an object made to be used and used well.

Listening Impressions:
This is a very detailed and accurate amp with a wonderful soundstage and draws out the details in any music and source you attach to it. This is how amplifiers should be in my book. Wire with gain!

Comparison with the GS-X:
Without the crossfeed I am unable to really find a good reason to pick between the Phonitor and my GS-X driving my headphones single ended (balanced drive appears to give the GS-X a slight edge). The sounds are very similar thought I would say the SPL is possibly (I am really not sure) a little less crisp up high than the GS-X but that’s about it. In the end it took many many trips back and forth and I’d be very very happy with either amp (well I already own one of them)

Crossfeed (Speaker Simulation) Functionality:
The idea behind the Phonitor is to have the professional engineer sit in their mastering/monitoring studio and tune the crossfeed until the sound field matches that of their room. I did this with my speaker setup and the results after much tweaking are downright impressive. It’s like listening to speaker but still with all the detail and crispness that headphones give you. You have to try it!

Measurements Etc.: (******* NOT PROFESSIONAL MEASUREMENTS ********)
I’ve done two different sets of measurements on the SPL Phonitor. The first set were done using the RightMark Audio Analyzer (RMAA) and my M-audio Transit USB to get measured response at the output. The other test measured the actual response of the headphones using my calibrated Behringer ECM8000 measurement microphone, headphone coupler, Room EQ Wizard Software (REW), and Edirol FA-66 audio interface. In both cases the source was my Bel Canto DAC3 and were done with no crossfeed on the Phonitor.

RMAA Results:
Frequency response (multi-tone): +0.08, -0.14 dB (20 Hz - 20 kHz)
Noise Floor: -87.8 dBA
Dynamic Range: 87.7 dBA (*** appears to be the dynamic range of the M-Audio Transit ***)
THD: 0.0013%
IMD + Noise: 0.0084
Stereo Crosstalk: -77.7dB

In general these results except for the crosstalk which is nearly 20dB higher than my GS-X. The rest are within the same sort of range exhibited by the GS-X though generally a little larger. The crosstalk is less of a concern with this amp because most users will use it with the crossfeed on and the crosstalk will be much higher then

.

**** update *****
One of the people from SPL contacted me and pointed out that my Dyanmic range number made little sense and I realized he was right. The dynamic range as measured from RMAA is going to come out about the noise floor because of how the test is set up and that does not necssarily represent the real dynamic range. SPL claims a dynamic range of 129 dBA and noise floor of -97dBu using their Audio Precision analyzer (drool)

REW Results:
This led me to wonder what the results would be with actual headphone response and here I compared the Phonitor with the GS-X after careful volume matching. Much to my surprise the measured response of the headphones (HD650 and D5000) with two amps was identical. This was suprising because the heaphone out of the Phonitor is supposed to be 9 ohms which should lead to a bass bump with the HD650s but I could not observe one at all in my REW measurements. I have attached a plot of the HD650 spectrum with two curves though you will see only one (I assure you that there are 2).


Summary:
Great amplifier and great crossfeed! Highly recommended.

I am sorely tempted to buy one of these amplifiers but I already have a headphone amp and have many others on the way so that will have to wait. I am talking to the product designers at SPL and hoping that they release just the crossfeed portion of their technology in a separate package that I can integrate into my system. I will miss this amp when I ship it out on Saturday.

 

[triode12]

Can you get the images to appear in front of you or are they still trapped within your headspace?

And does the crossfeed function increase soundstage depth and width as well?

 

[Dreadhead]

Quote:

Originally Posted by triode12 /img/forum/go_quote.gif Can you get the images to appear in front of you or are they still trapped within your headspace? And does the crossfeed function increase soundstage depth and width as well?

Yes the soundstage both expands and moves out infront of you.

For me it makes my headphones sound eerily like more detailed versions of my speakers.

 

[triode12]

Quote:

Originally Posted by Dreadhead /img/forum/go_quote.gif Yes the soundstage both expands and moves out infront of you. For me it makes my headphones sound eerily like more detailed versions of my speakers.

Thanks! Looks like I will have to check this amp out and others with crossfeed.

 

[LeMat]

I would be curious to know how this crossfeed compare to the PIC function of the last Lavry DA11.
Anyone got an idea on this ?

 

[suikodenii]

I would be interested in any differences between the phones in respect to the corssfeed/speaker simulation features of the Phonitor.

Previous impressions had indicated that the effects are more audible or impressive with open design hps.
In particular I am interested to understand how the Denons reacted to this.

Thanks for adding more impressions in that direction,
Chris

 

[Snacks]

Surprisingly, for me, I didn't read anything in the review that stuck out (+/-). Lookswise, the SPL Phonitor has a lot of old world charm going for it. As an added bonus, it's nice to hear that it sounds good to boot.

Good review, thanks for sharing!

Wish I was in the US so that I could hear a lot more of the great products for myself.

 

[Audio-Omega]

I thought Phonitor would be way better.

 

[mbd2884]

It's not as big as I thought it would be. From the first few pictures I had seen, I thought it would be giant.

But great review, sounds awesome. Wonder if vviranj (spelling?) will comment.

 

[achristilaw]

I have lived with the Phonitor for Six Months, and it's charms will only endear you further the more time you spend with it!

Most Amps take Music and extrude it out one end, much like a child's play-doe machine. Remember balling a bunch of clay and pulling the plastic handle down and watching a star pushed out waiting to be cut.

Music just appears and is displayed with a natural, unforced quality out of this amp. You listen for extended periods with great clarity not noticing any grit or grain. Manage the best Source possible and you will be rewarded!

The crossfeed is not a gimmick with this amp as it is with others. You can make shifts in the spatial response....without drastically altering the frequency response. Maintaining plausibility to the musical event, and that manages to keep the listening really engaging.

It's one of a kind and should be sought after!

 

[Voltron]

Nice review Chris! I am leary of sound tweaking, but it would be cool to compare the Phonitor with the Lavry DA11. Hopefully a Phonitor will make it to CanJam so we can do that because Lavry Engineering will be there as a vendor.

 

[Dreadhead]

Quote:

Originally Posted by Audio-Omega /img/forum/go_quote.gif I thought Phonitor would be way better.

I'm a realist when it comes to amps. "Way better" is nearly always and exaggeration when talking about them.

 

[Dreadhead]

Quote:

Originally Posted by Snacks /img/forum/go_quote.gif Surprisingly, for me, I didn't read anything in the review that stuck out (+/-). Lookswise, the SPL Phonitor has a lot of old world charm going for it. As an added bonus, it's nice to hear that it sounds good to boot. Good review, thanks for sharing! Wish I was in the US so that I could hear a lot more of the great products for myself.

For me the wire with gain is about as good as amps get and this amp excels at it. I'm really torn and may get one and then figure out what to do with it later.

Maybe HD800s + Phonitor == Dream work setup

Also I have it on good word that SPL are working on a cheaper amp with less monitoring features too.

 

[Kees]

Quote:

Originally Posted by Dreadhead /img/forum/go_quote.gif For me the wire with gain is about as good as amps get and this amp excels at it. I'm really torn and may get one and then figure out what to do with it later. Maybe HD800s + Phonitor == Dream work setup Also I have it on good word that SPL are working on a cheaper amp with less monitoring features too.

I would really like a smaller more simple model (and cheaper).
I heard the Phonitor and it definitely is the best solid state amp I heard so far. I would really like to have one, but it is too expensive for me right now.

 

[Caution]

Nice review, I'm looking into the Phonitor as a possible future amp.

So I take it with crossfeed on you prefer the Phonitor to the GS-X single ended? Did you test how the Phonitor with Crossfeed enabled stood up against the GS-X in Balanced mode?