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SPL Phonitor X Review (DAC & Headphone Amp)

Martin

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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 :facepalm:
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 :)

There are also considerable anecdotal reports of these breaking under fairly normal usage.

The manual contains some ominous warnings:
To protect the headphone power amplifier stage and guarantee a long and consistent performance please note:
• Turn down VOLUME before swapping headphones.
• Never insert a mono jack plug into the front panel stereo jack.
• Make sure that the headphones stereo jack is fully inserted.
• If you use an adapter from 3,5 mm to 1/4" (6,35 mm) on your headphone make sure that the adapter is fully screwed on respectively fully plugged in.

The more I find out about this unit the more I believe it is just poorly designed.

Martin
 

Martin

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Not sure if anyone else posted this but looks like @WolfX-700 tested the Phonitor XE version back in December and got better results out of the Headphone measurements. That version of the amp does not have a pre-amp out.

https://www.l7audiolab.com/f/measurements-of-spl-phonitor-xe-headphoneamp/

I don’t read Mandarin so I used Apple translate in Safari. It looks like the results are slightly better but still not great, especially considering the price. Several “not bad” comments are not confidence inspiring. I wonder how it would compare to a $499 Schiit Jotenheim 2?

Martin
 

Dueprocess

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Not sure if anyone else posted this but looks like @WolfX-700 tested the Phonitor XE version back in December and got better results out of the Headphone measurements. That version of the amp does not have a pre-amp out.

https://www.l7audiolab.com/f/measurements-of-spl-phonitor-xe-headphoneamp/

These results do show ~135 dB of dynamic range, though (which matches SPL's listed specs). I guess that gives me confidence some of their other models might meet their posted specs, too (and maybe Amir's test didn't show that for this particular unit d/t issue w. the refurb).
 
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Harmonie

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I think the lesson from this is twofold.

1. Dont buy anything red
2. Find out what @Martin has and is planning to buy, then buy something else!

Poor @Martin
After all his issues with volume button, screen on his other dac, then the (Red) Yulong, now this ....

I have to admit, @Jimbob54 resumes it quite well :p

But finally, I think he made a good decision and it's Black ;)
 

Harmonie

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

That's the core point.
The "DAC" is an optional "module".
It gives the feeling of an added 9$ dongle - I know, I exaggerate, but still, that's the feeling I have.
 

Deolum

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These results do show ~135 dB of dynamic range, though (which matches SPL's listed specs). I guess that gives me confidence some of their other models might meet their posted specs, too (and maybe Amir's test didn't show that for this particular unit d/t issue w. the refurb).
Phonitor 2, X and XE are identical.
 
OP
amirm

amirm

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FYI the unit is packed to go back but I did look up the dip switches and #2 was on.

On getting 135 dB dynamic range, that is likely at full output which can be quite high. I measure mine at 4 volts as I do all others. Otherwise there is no way to compare one device to another.
 

Dueprocess

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FYI the unit is packed to go back but I did look up the dip switches and #2 was on.

On getting 135 dB dynamic range, that is likely at full output which can be quite high. I measure mine at 4 volts as I do all others. Otherwise there is no way to compare one device to another.

Very possible. Seems most testing done here was at 4v (https://www.l7audiolab.com/f/measurements-of-spl-phonitor-xe-headphoneamp/), but it's not noted explicitly re: the dynamic range measurements. It wouldn't surprise me if SPL is measuring it at a higher output to reach the quoted spec, either (in that I wouldn't put it past any manufacturer to use relatively unrealistic input voltages in pursuit of marketing material, based on what we've seen here...).
 
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restorer-john

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The manual contains some ominous warnings:
To protect the headphone power amplifier stage and guarantee a long and consistent performance please note:
• Turn down VOLUME before swapping headphones.
• Never insert a mono jack plug into the front panel stereo jack.
• Make sure that the headphones stereo jack is fully inserted.
• If you use an adapter from 3,5 mm to 1/4" (6,35 mm) on your headphone make sure that the adapter is fully screwed on respectively fully plugged in.

The more I find out about this unit the more I believe it is just poorly designed.

Have to agree with that. They are buck-passing the protection (or lack thereof) on to the end user.
 

Deolum

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FYI the unit is packed to go back but I did look up the dip switches and #2 was on.

On getting 135 dB dynamic range, that is likely at full output which can be quite high. I measure mine at 4 volts as I do all others. Otherwise there is no way to compare one device to another.
Thanks!

That means that its output was boosted by +22 dB. I only went to +12 dB and can confirm that this already sounds ****** so i can imagine that +22 dB sounds even worse.

However i don't find it fair to compare this with other headphone amps that have 0dB as their high gain. That also explains why i experience it as superior with sensitive headphones than with harder to drive headphones.

The stated 3,7 Watts are indeed in maxed out dB state and its clearly not the way the amp should be used to get good measurements.

With all respect to your measurements and the forum i think a bit more caution would be appropriate in those situations which means you should maybe first read the manual and your community should watch the measurements a bit more critical.

Measurement and all is fun but your forum has reached a size now that it has an economical influence on many brands you tested so your tests should be a bit more meticulous.

Thanks for letting me state my opinion here!
 

the_brunx

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IMO in light of this critical information I think the headphone amp section deserves to be retested. It will be a shame not to. preamp performed well I think the headphone section at different gain settings will too.
But I’m also pretty sure there are studios/people using this who don’t know about the gain settings underneath, it’s just seems unlikely that people will always be flipping such a big expensive well painted amp around each time when plugging different heaphones in.
 
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Zensō

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IMO in light of this critical information I think the headphone amp section deserves to be retested. It will be a shame not to. preamp performed well I think the headphone section at different gain settings will too.
But I’m also pretty sure there are studios/people using this who don’t know about the gain settings underneath, it’s just seems unlikely that people will always be flipping such a big expensive well painted amp around each time when plugging different heaphones in.
I have to agree.
 

Deolum

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IMO in light of this critical information I think the headphone amp section deserves to be retested. It will be a shame not to. preamp performed well I think the headphone section at different gain settings will too.
But I’m also pretty sure there are studios/people using this who don’t know about the gain settings underneath, it’s just seems unlikely that people will always be flipping such a big expensive well painted amp around each time when plugging different heaphones in.
Gain settings at the bottom is really useless. I basically had to uncable it every time, find a small tool to change the settings and then set the whole thing back up.

Given the distortion that comes with the elevated gain it's not really usable this way so it's better just left in standard gain mode.

I don't blame the headphone amp for the distortion though because i think it's just the nature of things that elevating the gain above 0dB creates distortion. Thats why usual headphone amps high gain caps at 0dB and low/medium gain is negative dB. However some people don't seem to notice that. I had another amp that also offered, additionaly to the normal low /medium/high gain, a +10 dB boost gain resulting in massive audible distortion and one guy told me the headphone now had "more headroom".

The amp itself sounds beautifully with normal headphones. That means zero noisefloor with IEMs and sensitive cans like Denon AH-D9200 and more than enough power for a HD600. For lower sensitive 600 Ohm cans and hard to drive planars like Susvara or HE-6 i think its suboptimal.

Volume can be controlled remotely. You can basically use every infrared remote lying around.

Crossfeed is very practical for me but i lack comparison to other crossfeed solutions here. Overall i used this one way more often than the Adis crossfeed. From what i've heard from guys who know their shit the Phonitors crossfeed is best in class and also the main selling point.

Three inputs (2 XLR and 1 RCA) are very practical. RCA is in standard mode reduced by -10dB but can be elevated to 0dB via a dip switch on the bottom which can be done without a problem since switching from negative to zero gain doesn't harm the soundquality (contrary to switching from zero to additional gain).

The amp is unbalanced thus using the SE connectors should theoretically have a slight edge compared to using the XLR connectors here which should induce some kind of distortion. However XLR are also perfectly fine.

Personally i've never listened to the dac and probably wouldn't use. I think there are better solutions.

If you want to save money just take the Phonitor 2 instead of the X. It's the same amp and preamp with a few more features and way less expensive. Only thing that it doens't have is the XLR out which is inferior to the 1/4 output anyway.

Personally i couldn't care less about the VU Meters and the build quality but coming from a way more expensive amp i think the Phonitor is actually a very good package. I'd also love to see it retested at 0dB gain.

I have a Topping D90 + A90 stack on the way and i'm looking forward to compare it to my current setup.
 

cursive

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Gain settings at the bottom is really useless. I basically had to uncable it every time, find a small tool to change the settings and then set the whole thing back up.

Given the distortion that comes with the elevated gain it's not really usable this way so it's better just left in standard gain mode.

I don't blame the headphone amp for the distortion though because i think it's just the nature of things that elevating the gain above 0dB creates distortion. Thats why usual headphone amps high gain caps at 0dB and low/medium gain is negative dB. However some people don't seem to notice that. I had another amp that also offered, additionaly to the normal low /medium/high gain, a +10 dB boost gain resulting in massive audible distortion and one guy told me the headphone now had "more headroom".

The amp itself sounds beautifully with normal headphones. That means zero noisefloor with IEMs and sensitive cans like Denon AH-D9200 and more than enough power for a HD600. For lower sensitive 600 Ohm cans and hard to drive planars like Susvara or HE-6 i think its suboptimal.

Volume can be controlled remotely. You can basically use every infrared remote lying around.

Crossfeed is very practical for me but i lack comparison to other crossfeed solutions here. Overall i used this one way more often than the Adis crossfeed. From what i've heard from guys who know their shit the Phonitors crossfeed is best in class and also the main selling point.

Three inputs (2 XLR and 1 RCA) are very practical. RCA is in standard mode reduced by -10dB but can be elevated to 0dB via a dip switch on the bottom which can be done without a problem since switching from negative to zero gain doesn't harm the soundquality (contrary to switching from zero to additional gain).

The amp is unbalanced thus using the SE connectors should theoretically have a slight edge compared to using the XLR connectors here which should induce some kind of distortion. However XLR are also perfectly fine.

Personally i've never listened to the dac and probably wouldn't use. I think there are better solutions.

If you want to save money just take the Phonitor 2 instead of the X. It's the same amp and preamp with a few more features and way less expensive. Only thing that it doens't have is the XLR out which is inferior to the 1/4 output anyway.

Personally i couldn't care less about the VU Meters and the build quality but coming from a way more expensive amp i think the Phonitor is actually a very good package. I'd also love to see it retested at 0dB gain.

I have a Topping D90 + A90 stack on the way and i'm looking forward to compare it to my current setup.

Your statement about most headphone amps being 0db gain in "high gain mode" is not correct in my experience. For instance the A90 on balanced output has 15db gain, smsl sh-9 10db high gain, thx 789 16db in high gain. I believe it's more common to see 0db as the low gain option, but there are some amps with three gain modes like thx 789 that have a negative gain setting.

All those amps have positive gain numbers without all the distortion and problems that the spl phonitor has, so I think we need to hold it to the same standards, of not higher standards because of the price.
 

dep14

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Thank you for this review. I have been strongly considering the Director MKII which is directly related to this unit. While I actually don't worry quite as much about Amp and Pre-Amp measurements as I sometimes like a little coloration, I do not want coloration or poor performance in the DAC. I like my source to be accurate, and I might color to taste from there...
 
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