PENON OS133 Type-C to 3.5mm Audio/4.4mm DAC/AMP

The Penon USB OS133 Type-C Dongle

Reviews:
You know I get sent stuff to review all the time, but every once in a while something super cool comes along. Now this item is one that I would have least expected to be writing about at this place in time. Why? Well I have about 7 other reviews in sequence to tell about. Yet, this little, yet big OS133 Dongle has jumped to the start of the line. Why, sound of course silly. We often judge stuff by price or by looks……..and normally bigger is better. Bigger TOTL Flagship IEMs, bigger more expensive desktops, heck look at the systems (the full systems) posted here on Head-Fi, and they take up whole rooms with $1000s of dollars in gear. And this OS133 Dongle review doesn’t go to undermine any of those efforts........as they are personable, and commendable for what they are…………..only most of this stuff never leaves the personal listening room, as it can’t.

Around 2007 Apple created the Apple Dongle and what was to follow was a complete shift in how we use tail technology. If you were wondering, Apple must have known at some point they were going to part ways with the 3.5mm jack audiophiles used for listening. I mean sure audiophiles have always been near the bottom of the Apple hierarchy…….seemingly this small group of fanatics who focus on every little detail of playback. The mainstream are after only ease of use and decent sound and when the two ideas are conceptually joined a marketable item is introduced. And sure I have nothing against the Apple Dongle, except I feel it is way overrated.




The Apple Dongle:
Sorry, but ever since the unit in question came out I have been on my soap-box telling the world that it is limited in quality. Many reviewers ended up being known for telling how the Apple Dongle is all you really need. They will quote specifications and talk of noise floor and crosstalk, that 48 kHz and 16 bit is all you will ever need in your life. As such use is totally convenient, and it is hard to grasp how darn spoiled we are up to this point, with so many low cost digital sources.

In fact I went at one point and tried to get a grip on just how resolving the Apple Dongle truly was……meaning I don’t care about specifications, as at times we don’t know why a product is so musical, but it is. So I took the Apple Dongle and amplified the signal and did comparisons to other amplified signals. And guess what I found? There was a limit to just how wide the stage was, there was only so much separation of imaging, and while neutral, there was only so far the Apple Dongle went to generate a fully involving low-end. I was looking at the Apple Dongle under an amplifier microscope. Of course that was in the days when there wasn’t all kinds of Dongles in 3.5mm and 4.4mm to be had.

So amplifiers are different. This may sound stupidly simple to say, only many still are found to hold out in there opinion. I mean if it has been your cause to enlighten the world since 2007 about the infinite specialness of the Apple Dongle, it is a little hard to backtrack now……so the best thing to do is shut-up………and that is what is taking place by the old promoters…….as you almost never in 2024 hear about anyone promoting just the Apple Dongle for pure sound quality alone. Now those promoters speak about size and convince………and later sound quality.

But what if, what if there was a new invention which changed the course of history once more? Is there room for it? Do you really need more than this Penon USB Type-C OS133 Dongle? Remember I’m a snob, in that I normally always gravitate towards more expensive gear being of higher quality. Yet audio is probably 10-20% psychology! Meaning when we look at the apparatus in place the sound magically improves, yep……more lights, more cost, more hype, better sound quality. Except not here……………

You see I learned a lot from this OS133 Penon Dongle we have here. But somehow I felt, I had an intuition about it, don’t ask me why. Intuitions are those things that are outside of logic, the messages we hear from our inner voice taking, and normally that inner voice doesn’t give reasons why it chooses to like stuff, it just does.

Again, this doesn’t totally make a whole lot of sense, except if you do glance at the specifications they are good and maybe seem to answer the reasons why this little piece of wire rocks?

One of the great ways to test a new piece like this is to combine it with a new great IEM. Now what that does is confuse the listener. Due to possibly liking the IEM tone and having it multiply the Dongle tone we are slightly disoriented as to where this quality is coming from. Sure reviews are about trial and error and using known devices to (still subjectively) test other newer devices. Except the opposite ways also are going around your expectation biases to form a kind of new bike Christmas party.

Those new bike Christmas parties are what Head-Fi is all about, never let anyone convince you otherwise.

The realities discovered:
So I don’t want to rain on the Penon Type-C OS133 Dongle parade so soon, but I really need to go over this concept even at this early point. The file server you choose, meaning the digital input will have a slight effect on how this guy sounds. Why……again we are bucking heads with the sound science folks who state that 1s and 0s are all the same, that any form of digital input is exactly the same. I review stuff now, but back in the day I was truly all about digital sources making a difference, not a lot of difference but it is there. Maybe it’s my hearing, or it could still be psychology that affects this………except what I believe is the digital source you use makes a difference. What that means with daily use, is that a small percentage of quality boost will come from a dedicated file server, that a phone with 10 things going off in the background will create digital noise, that there are clocks in place digitally that align the pace and instrument/vocal quality into slightly better resolve and better (faster) imaging. So in real time, going out of the house and hooking this OS133 Dongle to a phone is going to be great, but there is always a chance hooking it to a computer or DAP may allow you a clearer window, just slightly.

Tone:
This is a totally subjective thought. And once again this does not always go along with our preconceived ideas on the tone we ourselves normally like. You see I’m totally into warmer and more musical ways of hearing music. That in itself could be the reason I was only moved so far emotionally by the Apple Dongle, as it is by many accounts thin and sterile sounding, I needed to warm it up, to thicken it up, to basically mess it up, and put the sound into a bigger room. Yet what if I told you this Penon OS133 Dongle does something which even convinced me that I could get into its sound? Yep, resolution, and while the Penon Dongle has full-on thickness of sound, I have heard warmer tones……………I would even chance to call it neutral with technicalities.



Neutral with technicalities:
What is that? It is what you will hear when you find better up steam signals. Simply put everything is clearer so you hear pace and imaging effects clearer. You are closer to the actual source therefore walking into the middle of it. When finding yourself inside this zone, the overall effects are simply that things like reverb and transients take on a new level of separation, you hear this separation. Part of this can’t be easily put into words………and I’m sorry but using an old audiophile term just seems to work here, and I have no other choice but to use it.

Effortless:

Yep, effortless:

It means that there are subtle separations into the perception of stage which keys in on specific movements of speed into which we perceive the time domain. This time domain is where effortlessness comes from, yet it always has to be connected with an increase of detail to see it.

The end results are again an old audiophile adage……..sorry but no other way to write this down.

Transparent:
What this transparency does is offer that extra level. Now you may question what are the signposts of this illusion. And while of course it’s real, yet all this is a regeneration of the original recording, and therefore a delusion of reality, except the closer we can get, the real this virtual reality is. And of course detail is a huge part of that……….except what if I told you part of that detail is the construction of reverbs, and the transparency is the actual texture of those reverbs. Sure they have always been there, especially in the midrange and treble……..but the closer we are positioned the more intricate stuff starts to appear. And when you add separation to that (reverberation) detail, now those textures can be viewed holding 3D realms of size being forward and back holding air and their very own almost infinite drop-offs. Where sure most of all this is always taking place, only the spot lights were tuned-on and now all the trees and animals of the forest can be accounted for.

So? We are going somehow into the realm of both note-weight, transparency and neutral. Yet still holding enough 3D imaging to make this somehow beat out a murky overly warm example of music. So the musicality and the trigger of excitement is thoroughly simply from the details and balance here.

Take note:
Both of these Type A USB to Type C USB adapters do exactly the same thing, but the longer one is shown in the above photograph.



PENON OS133 Type-C to 3.5mm Audio/4.4mm Balanced 384KHz/32bit USB DAC AMP Cable Adapter for Android and IOS

Description
CX31993+ MAX97220 Type-C 384 KHz/32bit digital audio USB Amplifier

It‘’s a Type-C digital audio headphone USB adapter PCBA solution.

The built-in CX31993 digital audio codec chip and MAX97220 power amplifier chip support up to 384KHz/32bit sampling rate.
Excellent mobile compatibility Android

Specification
Interface: Type-C
Analog Earphone impedance: 32ohm
Decoding rate: up to support DAC 384KHz/32bit; ADC 96KHz/24bit
SNR @1kHz: 100dB
THD+ N@1 KHz: -93dB
Crosstalk suppression @1 KHz: -55dB
Cable material: 4 shares,single share is 133 cores.Black nylon sheath,OFC silver-plated cable with carbon fiber plug accessories
Cable length: 8-9cm (without plug)
Cable total length with plugs : 3.5mm is about 14-15cm , 4.4mm is about 15-16cm
Available type :
Type-C to 3.5mm Audio for Android and IOS
Type-C to 4.4mm Balanced for Android and IOS

Power draw:
My phone........I would have used the phone, but I could here the quality prepared from an Audiophile DAP as a file server to genuinely improve playback performance. Meaning phone playback was great, but there was the extra smidge of nice detail from the USB Type-C port of the HiBy R3 II. That meant that is was simply better and more listenable. As discovered the OS133 Dongle never even hints at changing temperature.....it never gets warm or ever hot? You would think there would be some clue as all this metal hardware at the decoding plug, but no it never changed. So no waist in power management, and the benefits of running most of the day at loud volume levels from the internal HiBy R3 II DAP. In fact it seems like it helped the DAC play longer as the DAP was not using power reserves for amplification?


The cable part:
Now let’s talk about the actual cable material used. Many of course don’t believe in cables, yet here everyday I experience differences. So it is safe to say even if you don’t hear differences, at least you're buying insurance that they are there, in case one day you do hear differences, or are beginning to hear differences.

The OS133 is a highly transparent conductor which Penon has specifically chosen to be put in use. As such many of us have had a history with the OS133 cable, only Penon has one upped the clarity. Yep, the question is how do you improve transparency. You simply double-up the transparency and the overall stage gets bigger, taller, wider, thicker. And that is what happened, as they 2X the cable material to make a Space cable to go with the Dongle.

Type-C:
Where of course you could use an adapter to make a Lightning connector for your OS133 Type-C Penon DAC/Amp except that adds extra connections and may or may not get the same exact signal. You see if you look here, there are less parts than a regular Dongle as no stand alone cable is needed the Dongle IS the cable.

Comparisons:


Penon Tail Dongle:
Simply thicker sound and while still very much like the Penon OS133 USB Cable. But there was a totally different sound to a point where not using the Tail resulted in a slightly less bass laden sound, yet not as thick meant that there was crispr imaging, and faster transients to boot…….and it was smaller. While you may not ever know it when using IEMs, the authoritative power of the Penon Dongle simply drives full-size headphones better. I mean sure you may hear a slight bit of this authority seeping in even when using IEMs, though that is what this whole review is about, the subtle gratefulness of the OS133 Dongle, making having both complementary and more necessary than you may first guess.

Shanling UA3 Dongle:
Maybe slightly softer and polished than the Tail and the DEW4X? Where the stage was definitely more relaxed and not so in-your-face as we have with other Dongles. The Shanling is refined yet holding a softer style of replay, still I love the UA3 and could never imagine life with-out it. Still this new Penon OS133 Dongle is way cheaper and still holds a style of personal magic, taking steps to bring the details slightly more forward and airy with increased vividness over the treble areas present and still adequate with the UA3.

SIMGOT AUDIO DEW4X Dongle:
Great wide stage offering again a well done performance, at while different, yet the same, the Penon cable simply was actually thinner but crisper again? The DEW4X offers up again more power to drive full-size headphones, really to a place you can't even try as it is so loud, but along with that we are given dampening which seems to increase low-end girth and stature? This same personality is still offered by the DEW4X into which the midrange is heard, simply more present and accounted for. Yet that is not the avenue we are driving down with the OS133 Dongle, we don't care about power, we simply want vivid clarity without the lower midrange baggage and slowness, we want what we have found is neutral with the OS133 Dongle.



Penon USB OS133 v the HiBy R3 II:
This is the hardest test of all. Only because we are also using the DAP to be the digital file server to our device in question. Set up like the picture shown, we are utilizing the Penon ASOS Cable, the Penon Globe and changing from the output of the DAP to the output of the OS133 Dongle. This in fact is a super easy way to judge sound because the time lapse between signals is about one second. The thing I want to emphasize here is that none of our Dongles and Dap were really that different, as none of them were exactly bad. We live in a beautiful age, really many are calling this the Golden Age of portable audio, being since 2013 huge changes have taken place in regards to the quality of personal audio. Basically it’s all good. The DAPs invented, the IEMs that have risen to popularity, the advancements shown at Head-Fi promote a lifestyle previously unknown in 2013…………….this has been a strong 11 years, no one will argue about that. The OS133 in ways outperforms the R3 II, yet it may be due to it's drawbacks that this takes place. Meaning because the OS133 is less powerful, it's cleaner and hold a more trim midrange, which just happens to promote top end detail.



It's personal leave me alone.........I want what I want.
Still all this is personal, it would be like smells of perfume at the perfume store, or vintages of wine, we have these moments of clarity and that’s mental clarity to where we relate with a tone, we are taken to this place between our ears inside the stage……….and whatever it is we relate at times to playback better than other playbacks. At times a thinner detail with less lower midrange stage can propel these small items of focus into the limelight, and it still is that perfume scent that is either loved by others or not……..really it is way lesser of an effect than the smell of perfume…….it’s almost nothing at all we are concentrating on. Yet those textures of decay, those effortless reverbs are real in our perception, so real we can remember those listening moments even days later. So that is real and meaningful, at least to us in our tiny little audiophile universe. As most would think we are slightly crazy, I would probably define it as obsessed. And not a little obsessed, a lot of obsessed. So the only way I can describe my experience is I took multiple days and long listening times, one because it was enjoyable, but two to make sure I was totally correct, at least to myself. So simply there are parts of the playback that are better with the OS133 Penon Dongle, that out shine what the HiBy R3 II does.

A unified and projected stage:
Simply a unified and projected stage holding elements of wonderful detail inside. Those detail grab hold of instruments and tones, detail of room reflections and transients to create what we are all here for, a moving and detailed replay. Now I want to emphasize that every IEM is different and there are many different responses and synergies to be discovered. Yet the point of this paragraph is that nothing seemed left out here, even though this Dongle is only $34.90……I may simply like the decoding chip it offers, and my option could be something as small as that?



Driving full-size headphones:
While it is interesting to finally test this one aspect out. As I don’t necessarily use Dongles to drive full-size cans…..It is still a test as to their power. And finally it really hit home here…….I mean I was waiting to find the drawbacks to the OS133 and it hit home here. As far as being able to drive even the easy to drive MDR-Z1Z……nope it was a total failure. I mean if you were away and had to listen to it, it was nice but in no way comparable to the Penon Dongle, the HiBy R3 II or the Shanling UA3. Even the little SIMGOT DEW4X did one hell of a job better. So that is that. What happens here is you can even turn the OS133 up all the way and it just gets loud enough, though due to limited dampening power we are only given so much bass presence. Upon taking the OS133 cable off and restoring playback with simply the HiBy R3 II it showed really who was boss of the full size cans………the Hiby was…….with its warm styled M response we are rewarded with not only clear bass, but the soundstage that a full on powerful rig accomplishes.

Conclusion:
Look, the Penon OS133 Dongle is easy to use and a lot of fun. You can go anywhere and find audiophile playback. Never in Head-Fi history has premium grade audiophile playback been to easy to afford and use, you simply plug it in and go. Sure the market is flooded with Dongles a this moment in time, there is no denying that fact. And sure they all sound slightly different and slightly the same. Still in my limited experience I have never come across such an item? Maybe they are for sale out there, maybe not. I can simply guarantee you will be happy with the tone, I simply don’t know how you could not be? There is even a chance that you may find the magic like I did……..it started one evening then continued till another evening and another. I tried to compare with other digital sources and found that while the OS133 Dongle was maybe not totally the size of the others stage size, it still offered a purity and a cleanness that was rare, rare and clear! Rare and still a great forward stage and back, top to bottom in imaging. If you have got my point, or not……I have done the very best to explain it nonetheless…….cheers!

$34.90
https://penonaudio.com/PENON-OS133-Type-C-DAC-for-iOS-Android

PENON OS133 Type-C 3.5mm Audio/4.4mm Balanced 384KHz/32bit USB DAC AMP Cable Adapter for iOS/Android

Description
CX31993+ MAX97220 Type-C 384 KHz/32bit digital audio USB Amplifier

It‘’s a Type-C digital audio headphone USB adapter PCBA solution.

The built-in CX31993 digital audio codec chip and MAX97220 power amplifier chip support up to 384KHz/32bit sampling rate.

Specification
Interface: Type-C for Android and IOS
Analog Earphone impedance: 32ohm
Decoding rate: up to support DAC 384KHz/32bit; ADC 96KHz/24bit
SNR @1kHz: 100dB
THD+ N@1 KHz: -93dB
Crosstalk suppression @1 KHz: -55dB
Cable material: 4 shares,single share is 133 cores.Black nylon sheath,OFC silver-plated cable with carbon fiber plug accessories

Cable length: 8-9cm (without plug)
Cable total length with plugs : 3.5mm is about 14-15cm , 4.4mm is about 15-16cm

Available type :
Type-C to 3.5mm Audio for Android and IOS
Type-C to 4.4mm Balanced for Android and IOS


Disclaimer:
I want to thank Penon Audio for their love and the OS133 Dongle review sample.

Disclaimer:
These are one person's ideas and concepts, your results may vary.

Equipment Used:
Sony WM1A Walkman DAP MrWalkman Firmware 4.4mm
Sony WM1Z Walkman DAP MrWalkman Firmware 4.4mm
HiBy R3 II DAP in 4.4mm balanced output
Penon Tail Dongle in 4.4mm balanced output
SIMGOT AUDIO DEW4X 4.4mm balanced output
Shanling UA3 Dongle 4.4mm balanced output