iBasso Audio P5 Portable Amplifier

General Information

Main Features:
- Three Channel or Four Channel compatible architecture design.
- A total of 8 gold-plated DIP sockets for OPAMPs and Buffers allowing for opamp or buffer rolling.
- 3 Gain settings for impedance matching.
- Bass boost to enhance bass performance.
- Powered by dual 9V batteries, or the P5 power supply.
- High output power, 660mW+660mW into 32Ω when powered by batteries, or 1000mW+1000mW into 32Ohm when powered by the P5 power supply.
- CNC engraved aluminum housing, which can be opened with just one screw.
- Come with iBasso P5, P5 PS, rubber feet, copper connection cable, and OPAMP rolling kit.

Latest reviews


Headphoneus Supremus
Pros: Sound, Design, Bass Boost
Cons: Battery, Size
The P5 is iBasso’s latest release, and coming in at the price of $529, it is iBasso’s current flagship portable amp. With their DX50 and 90 models, they really managed to gain a lot of fans with their clean and detailed signature and they have grown into one of the established names in portable audio. Having tried their recently released D14, I was looking forward to see how their flagship amplifier would fare.
We haven’t seen a dedicated amp from iBasso for a while now, and the P5 is the successor to the old P4. Though I have reviewed numerous iBasso products in the past, this is the first iBasso amp that I have reviewed, and given my experience with their other products, I certainly had high expectations for this unit. Let’s go on with the review and see how the P5 performed, and hopefully this will give those who are considering it a bigger picture of what to expect.


I don’t really feel like specifications really matter, but here they are for anyone who is interested. The output impedance is low enough for very sensitive IEMs, I did not detect any bass roll off. I am pretty sure the output is under 1 ohm, which is the case for every iBasso device I have tried so far.
Power Source:Dual 9V batteries or P5 PS
Frequency Response: 16Hz~80KHz /-0.2dB
Signal to Noise Ratio:-121dB (A-wt.)
Crosstalk: -72dB@32Ohm
Total Harmonic Distortion: 0.0018% (with 32Ohm loading)
Output power: 660mW+660mW into 32Ohm when powered by 9V batteries, or 1000mW+1000mW into 32Ohm when powered by the P5 PS
Bass: 0dB/+6dB at 100Hz
Gain: 0dB/+4dB/+9dB
Battery Life: depends on the OPAMP and BUF combination
Battery Charge Time:  8~16 hours with the P5 PS
External Power supply:  +/-15V
Recommended Headphone Impedance: 8~300Ohm
Case dimension: 2.87W x 4.84L x 0.94H (inch)
             73W x 123L x 24H (mm)
Weight: 201g or 7.1oz (without batteries)

Packaging & Accessories

The P5 and the power supply both come in similar packaging to the DX DAP series. They do not come in one package, the P5 and PS are separate. The packaging is my no means extravagant, but it still manages to look attractive. The foam in the box protects both the P5 and the Ps very well, they arrived with no scratches or dings. Under the P5 are all the accessories that are included with the unit.
To be honest, I felt like the P5 was missing a few things that probably should have been there. Surprisingly there were no rubber bands, which I suspect quite a few people would like if they want to tie their P5 to a source to use as a portable solution. There were feet included, but they were the foam ones, and slid very easily, it would be much better if iBasso included rubber feet for their devices in the future. There are some OP amps and buffers included as well as an extra screw for the P5. Also included was a 3.5mm interconnect cable, it’s just a generic one and if you are going to shell out over $500 for the P5, you should probably invest in a nicer cable. The PS comes with a power cable and a wall power cable. The power cable connecting the P5 to the PS feels very solid. Overall, the P5 includes everything that is necessary, but misses a few things.


The P5 comes with 3 gain options – low, mid and high. It’s pretty self-explanatory, adjust the gain depending on what headphones you are using with them. There is also a bass boost, which I think is the first that I have seen on an iBasso device, and that’s about it.
The bass boost is one of the best I have come across though. It is probably also one of the most subtle increases that I have used, the boost is small, but noticeable. It doesn’t really darken the sound and it doesn’t induce and bass bleed whatsoever. I found that the greatest area it affected was sub-bass rumble, it was much more satisfying when used with more neutral BA IEMs than already bass heavy IEMs like the 1plus2. It’s nice to see iBasso implement a very useable and effective bass boost.


Let’s start with the negatives first. Size. This thing is damn huge for a portable am and when stacked with a DAP, don’t expect it to fit into your jeans pocket. The footprint is very big for a portable amp and the thickness is bulky as well. There is no other way to put it, the P5 is simply a large amp that’s more transportable than portable. The only other con I can think of is that if you want to use the P5 with batteries, there is no way to charge them other than to use the included power supply or to take them out, it is rather inconvenient, would have been nice for there to be a more portable charging option. The stock configuration with dual 500mah batteries will last you approximately 6.5 hours. However, there are some 9V batteries which are larger, and you could potentially use the P5 for around 10 hours off a single charge.
The P5 is the nicest looking amp I have seen in a while. The finish is simply impeccable and it really looks like a high end product. Both the P5 and the Ps are CNC finished and the brushed metal looks awesome. The amp looks sleek and all the edges are well finished, it feels as much as it costs. It feels very solid ad sturdy, and was actually a little lighter than I would have expected. The PS is quite heavy though. Not sure how easily this scratches, but I’d be very careful with it to keep it looking the way it does out of the box.
I only used the P5 with the PS because I wasn’t keen on using it outside due to the size anyway. The jacks feel very good, I think they might be the same ones as the D14, which are rated for 10000 cycles. They are a little bit recessed, but not by much. Most plugs, even right angled ones should have no issues. The volume knob also feels very solid, and it doesn’t turn very easily so if you do happen to have this in your pocket, the accidental bump shouldn’t change the volume dramatically.
On low gain, there was very slight channel imbalance at very low volumes but none past 7 or 8 O’clock. There was very slight noise on low gain, it’s not completely silent, but it was completely unnoticeable when music was on. With headphones like the ATH-R70X, you won’t be able to hear any noise, even on high gain. There was no EMI when I took calls, Bluetooth and used a lot of electronic devices around it.

Testing Gear

Most of my testing was performed on a Tralucent 1plus2 using the D14 as a source. The interconnect I used was a Toxic Cables copper cable. I felt there paired very well together, the detailed DAC of the D14 and the P5 really brought out the best in the 1plus2. I did, however, use several different headphones such as the ATH-R70X, DN-2000, MH40 and the rockets. As a source I also tried the DX90, but I felt that the D14 was better overall, so I mainly just used the D14 to feed the P5. I also gave it a short try with the SE846 and the Roxanne. I used the stock OP amp and buffer combination that came with the P5, didn’t change anything.


The P5 is simply the best portable amp that I have ever tried, overtaking even the 627X that I compared it with. I held very high expectations for the P5 and I was not let down whatsoever, but instead, I was pleasantly surprised by just how much control and authority the P5 had. It somehow manages to sound effortless yet incredibly detailed at the same time. The P5 really sets a new standard for me. This has been burnt in for over 100 hours.


Perhaps the area that the P5 impressed me the most in was the bass. I have never heard another amp be so controlled and clean in this area before. The P5 manages to produce both visceral and extremely fast bass. This is not to say that it is bass heavy, because it definitely isn’t, it’s one of the most neutral amps that I have heard. The impact is very satisfying and the sub-bass has significant, but not excessive rumble to it. Bass extension is excellent, there is not bass roll off at all for those who are looking for some extra oomph in the lower end, the bass boost is a very good solution without compromising the midrange and treble. Detail is exceptional, every little kick and string are very well rendered and the decay is always just right, not too long or too short. The bass response is simply flawless for me, it manages to conservative, yet remain exciting.


The midrange has a sweet tone to it, but that is not to say that it is cold in tonality, because it is not at all. It is the typical iBasso midrange really, with emphasis on detail and clarity. While the midrange does sound quite flat, I don’t think that it is completely more neutral, to me it is very slightly on the brighter side of things. Vocals are the most natural that I have ever heard from a portable amp, the P5 manages to remain very clear without boosting the upper midrange. Pianos have a solid weight to then, they sound very natural and have a very realistic timbre to them. Instruments all sounded very euphoric and the P5 is very good at retaining detail from instruments and vocals. The P5 manages to sound natural, have excellent clarity without sounding sterile or cold at all. You’d be hard pressed to find something out there right now that tops this.


iBasso devices traditionally have a slight accentuation in the treble, but I didn’t really detect this with the P5. It is the first iBasso DAC or amp that I feel has a ruler flat treble. The extension is great, no roll off at all, and the detail is equally good. There was no sibilance in the upper regions at all. Initially, I actually felt like the treble was perhaps a little dark, even bordering on veiled, but after running it in for a while, it did open up. The P5’s treble really needs some burn in to sound the way that it should. Cymbals have adequate sparkle without sounding overly sharp. It excels in detail, just like the D14, it is one of the most detailed amps that I have heard and it really brings forwards the micro details in the background of the music. The P5 may not spear to be overly detailed at the beginning, but after burn in it is extremely good in the treble.

Separation, Detail & Clarity

The P5 is truly excellent in this area and completely trumps the already impressive D14. Separation is one of the main points I look for in an amp and the P5 does superbly here. Not once did I feel like instruments got muddled and with the SE846, it sounded amazing. Instrumental separation is its strongest area, with everything sounding remarkably coherent. Vocal separation is only slightly behind, but also very good. Nothing to pick out here, as good as it gets.
The detail is also immensely impressive. Compared to the HM-901’s internal amp, adding the P5 results in a significant and appreciable increase in detail which is very easily detectable. The microdetails are really revealed with a high end IEM like the 1plus2. Little rings and taps in the background that I didn’t notice before seem to pop up and it is certainly very impressive.
Clarity is great, partly due to the slightly elevated upper midrange and treble are that appears to be on most of the iBasso devices I have tried. It is because of this that I generally like their products, I prefer the slight upper midrange boost to improve clarity. Clarity on the P5 is second to none and it is truly impressive.

Soundstage & Imaging

With the Roxanne and 1plus2, the P5 pairing sounds like a full sized setup. The soundstage that the P5 presents is very wide and tall, but it is also somewhat three-dimensional. This makes the entire stage seem much more realistic and this is the main area where it is different to other devices. The HM-901’s soundstage was similarly expansive, but there was no depth like the P5. It is somewhat similar to the DX90, but it does it much more convincingly and you feel like you are in a concert hall and not listening to a pair of IEMs.
For imaging, the main IEM I used for testing was the Tralucent 1plus2 and it really highlighted the ability of the P5. The pairing is excellent and they sound awesome together, the imaging remained coherent even on the most demanding of tracks. The imaging was very accurate, and the best that I have heard from a portable setup.


This seems like it is going to be yet another successful offering from iBasso. It is brilliantly finished, feels like a true quality product and looks amazing. Then there is the sound, which is almost flawless for me. Yes, it could be slightly more neutral, and have a better battery life, but then it would sacrifice other areas. The P5 is by no means a perfect amp – nothing is perfect. It is one of the more expensive options out there, and its size restricts where you can use it. However, if you are looking for the best of the best, and money is not an issue, then the P5 is the amp for you. 
Very well written, clear and precise review.

I'm considering an upgrade from my D14 after having tried the Mojo for 2 weeks. Would you be able to compare the D14-P5 combo to the Mojo in terms of sound alone? As one of my good friends suggested, maybe the P5 would offer a good synergy being iBasso, and being comparable to Mojo price wise, I should probably try it out before I make my decision.

Thanks in advance, cheers.
Forgot to mention above that my main headphones currently are the Fidelio X2.

Any comments on my queries above, shall be greatly appreciated! Thanks again. 


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