WATCH FULL REVIEW HERE: https://youtu.be/18WvYI6_gqY
One of the most important things that a reviewer needs to tackle in their reviews is comparisons. How else can you get a reference point without comparing it to its peers? But a struggle that we have is that the process of conducting A/B testing is keeping the variables the same. Particularly, volume matching is a very important factor due to the Fletcher-Munson curve where the higher the volume of something is, the more emphasized the low and top ends are and the overall sound becomes more V-shaped. This can shift the difference drastically and might the difference between two sets vastly different because of volume.
So when I got the opportunity to review a product that will make this process INFINITELY easier, I took that faster than a child puts an unknown object in their mouth. So did this really make the process easier? Does it fulfill more than just a “reviewer’s tool”? And why should you get this even if you don’t review but have a big collection of headphones?
OVERVIEW
Fosi is a well-known and respected brand that offers DACs and amplifiers. I can’t just mention one product since they’re well known not only in the portable audio scene but even in the speaker or home theatre scene. From the likes of the BT20A 2-channel amplifier (which I’ve previously reviewed) to the likes of the Fosi DS1 dongle DAC, they’ve basically got all the sources you need. And when I say all, I mean all because they have sources for reviewers and studio mixers with the product of today’s review, the PH05. So what makes this particular 5-channel amplifier such a stand out in today’s amplifier market? Let’s start with the unboxing.
UNBOXING
The unboxing of the PH05 is quite simple with the box featuring line art of the amp itself with the distinct red mute/power button. The amp itself is seated in a foam cutout that also features the 12v power supply, the 3.5mm to 3.5mm cable, and the paperwork of the product. They were laid in a very accessible manner that allows it to be put back after use without any problems.
BUILD
The construction of the PH05 is very sturdy with a metal alloy construction throughout the amplifier and plastic knobs
From the top, we can find all 6 knobs (yes 6) of the PH05. The smaller knobs on top are the independent volume knobs for each channel and the center knob is the master volume. You can also find the mute and power buttons on the left with a bright orange color.
In front, we can find the 5 3.5mm channels and the aux input to plug into your source. This is not a LO and works similar to an AUX jack where you plug in something like your phone and your laptop but also DAC/AMPs and DAPs. However, you can use it on LO, with certain caveats that I will mention later.
On the back, you can find the 12v plug to power the device.
SPECS
Here are the full specifications of the device:
- Texas Instruments NE5532
- 310mW @ 32ohms each channel
- 5 output channels
- THD: <0.001%
- SNR: 105dB
- Terminating Impedance: 16-300 Ohm
- Work Voltage: DC12V/1A
SETTING IT UP
Setting up the PH05 is quite easy. You place the PH05 on your table, make sure that all the volume knobs are all the way to the right, plug the 12v into a power outlet and the AMP itself, press the orange button and when you see the orange light on the right, you may plug in your headphones and slightly adjust the master volume (I recommend around 9 o’clock) and then turn the volume knob of the specific channel.
You can now also plug the AUX from your music-playing device like a smartphone, laptop, DAC/AMP or DAP. I will go in-depth with my findings with source pairings very soon.
I highly recommend playing around with the master volume first as this will dictate the base volume of each channel. Once you’ve set up a comfortable volume for your headphones, you may start plugging in the other headphones you intend to use.
If you need to mute or turn off the device, you may click or hold the orange button respectively. Muting the device will turn the LED from orange to blue and will turn off once it’s off
SOURCE PAIRING
One thing that I discovered with the PH05 is that not all sources are equal. While the amplifier has its own dedicated amplifier chip, the device you choose to plug the AUX cable into can also affect how much power you’ll be getting for your headphones.
For this testing, I used the Huawei Nova 7 SE (non-HiFi smartphone), Fosi DX1 (combo DAC/AMP), and HiBy R3 II (DAP).
I found that out of the three, the Nova 7 SE had the lowest output, followed by the DX1 on High Gain and the R3 II on LO.
However, the limit of the power is 310mW which means you can’t throw in a 1-watt amp and expect it to match that power. However, 310mW is more than enough for portable in-ear monitors and easy-to-drive headphones.
SOUND
The sound of the PH05 is relatively neutral. It was a very similar listening experience to the HiBy R3 II with a very neutral tone but didn’t compromise too much in the dynamics. It’s not as clean or dynamic sounding as something like the DX1 or as transparent or as crisp as the R3 II, but it does a fantastic job for its use case and especially the price. It’s able to bring out the nuances of IEMs and doesn’t sound compressed or dull at all.
The issue that I have with the PH05 is the noise levels. This shouldn’t be a problem with full-size headphones but might become an issue with very sensitive in-ear monitors. I used the Simgot EW200 which is a very sensitive IEM with 16ohms impedance and 126db sensitivity. When I plugged it into the PH05 and put the EW200s in my ears, I immediately got a flashback from when I owned the VE Megatron. It’s not as bad as the Megatron, but it’s definitely audible.
However, for a $39 5-channel amplifier, I would say the sound is acceptable. Nothing that will blow the water compared to more expensive, dedicated DACs, but nothing too compromising that can be immediately audible.
USE CASES
So now, why should you even consider the PH05? Well, there are a lot of use cases for this product, so much so that I genuinely think that this is the most versatile amplifier that I’ve ever tried.
REVIEWING PURPOSES
First and the most obvious one is reviewing. As a reviewer, comparisons are some of the most important things to include in your reviews as they provide context and reference for the people reading or watching your review. If they have the IEM or headphones that you’re comparing this IEM to, they’ll have a better idea of whether they’ll like it or not.
However, there are many factors that come into play that might skew one’s perception and comparison. The most important one is volume. I’ve always believed that volume is one of the most crucial factors in how someone perceives headphones. This is due to the Fletcher-Munson curve that, for the sake of time, will try to simplify.
In basic terms, the higher the volume you listen to, the more emphasized the bass and the treble are and makes the overall sound more v-shaped compared to lower-volume listening. This is a MASSIVE simplification of a very complex topic and I highly recommend reading more on it, but that’s a gist of this.
Putting this into the context of the PH05, the PH05 has independent volume knobs on each channel which allows you to compare different headphones at the same perceived volume. You can go more technical and use dB sensors to know exactly how many dBs you’re listening at, but just having a consistent level of volume when comparing two headphones side by side is MUCH more efficient and easier than unplugging, changing the volume and then rinse and repeat. Obviously, this isn’t a scientific way of comparing as there are still other factors to consider. But this is arguably a much better option, especially for headphones with greatly varying impedance and ohms.
For Enthusiasts/Audiophiles
But reviewers aren’t the only ones who will benefit from the PH05. Enthusiasts and audiophiles with hundreds of headphones in their collections will have a much easier time comparing them with the PH05.
With it’s simple and easy-to-understand set-up, any enthusiast can use it to compare 5 headphones at once and share their findings with others or just note them down to get a better understanding of their audio journey and experiences.
For Audio Shops
The PH05 would also prove to be very useful in audio shops where you can demo headphones. I’ve been to our local headphone dealer many times before and my biggest problem is having to set-up my audio sources, borrow all the headphones, and compare them one by one with the right volume. This is very time-consuming not only for me but for whoever wants to demo next.
The PH05 can solve that issue as the headphones could already be plugged into that one source and all the headphones to the PH05. All you need to do is take the headphones off and put the other headphones in and compare to your hearts desires without the issue of plugging and unplugging and volume matching.
For Music Producers
Audiophiles aren’t the only ones who can benefit from the PH05. Professionals or upcoming professionals on a budget who need a cheap but good-quality multi-channel amplifier can use the PH05 when producing their music with a group.
I’m not an expert with audio production to really point out every use case that music producers can use this on, but I have dabbled with music production in the past and when collaborating with others, it helps have a consistent but high-quality playback that isn’t through an iMac (yes we mixed on GarageBand) speakers.
For Home Studio
Music listening is fundamentally a social thing. People jammed and danced to music even in the Stone Ages and now, we have the option to listen to music with people without bothering others who choose not to listen. That’s the beauty of the PH05 as you can plug in multiple headphones for your friends and family to listen to and enjoy music in a controlled but still enjoyable and solace environment. It may seem a little dumb when you first think about it, but I have experienced cases where my friend and I wanted to listen to this particular song or album but we were in a room where we weren’t allowed to play music through our speakers. The PH05 offers a great way to do this, as long as you have somewhere to plug it in of course.
But music isn’t the only thing you can do with the PH05. Watching movies or TV shows in silence is also a very common occurrence, especially in a household where you, your friend or your siblings are night owls and you want to watch movies but can’t blast your TV or speakers while doing so. The PH05 allows you to binge your favorite movies or shows without having to disturb the rest of the household.
For Other Social Events
There are specific social events like podcasts, classroom settings, social gatherings, and the like that the PH05 may be used to allow people to monitor their own voices or the content they are consuming in an easy manner. This is more for those who want max 5 people to listen to something in solitude without being bothered by the external world like in music class where the students may want to listen to the instrumentals in their own headphones.
CONCLUSION
The Fosi PH05 is one of the most versatile and practical amplifiers on the market right now. 5 independent channels allow for so much possibilities ranging from the audiophile use cases to monitoring.
While it may have some issues like the noise level being quite audible when plugging very sensitive in-ear monitors and the need to have a power supply in order to work (as it is an independent amplifier), its use case and price overshadows its cons. So if you’re looking for a budget-friendly but high-quality multi-channel amplifier, the PH05 is for you.
Thank you for reading my review on the Fosi PH05. If you would like to order one, consider using a non-affiliated link below:
Fosi Audio Shop https://fosiaudio.com/products/fosi-audio-ph05-5-channel-headphone-splitter-amplifier
Amazon US：https://www.amazon.com/dp/B0CYLSD4GJ?maas=maas_adg_613A775C7F46A4343219F738344AF687_afap_abs&ref_=aa_maas&tag=maas
UK：https://amzn.to/453fXLY
CA:https://amzn.to/452GdWI
FR:https://amzn.to/4c1AJ0G
