JDS Labs C5 Portable Headphone Amplifier Review


It's not every day that we get to review an amp. And if you know anything about headphone amps it's that they make things sound...a whole lot nicer. Headphone amps made by JDS Labs are in particular a favorite of ours purely because they are engineered with a magical switch that reads "switch on for the ultimate audio experience of your life". Well not exactly, it's more of a bass toggle that takes your headphones into a whole new set piece of unimaginable, untapped potential. If there's ever was a small headphone amplifier company that knew exactly what portable headphone amp users were looking for it's JDS Labs. Much has changed since our review of the company's famous Altoids tinned CmoyBB amp from a few years ago. And in that time JDS Labs introduces a number of new and improved offerings including the C5, a portable headphone amp that's powered by Arduino firmware and built to audiophile standards with an explosive driving ability and great all-day battery life.

Want to take your headphones to the next step? Have you found the perfect pair of headphones that fit comfortably, look great and sound amazing, yet you still wish the bass was as impressively brilliant as the all the rest? Then be sure to check out the full review down below and we just might be able to help you find what you were missing out on this whole time!


Suffice it to say that every non-powered headphone without a built-in amp is in desperate need of amping. Let's just call it the turbo charger of headphones and in-ear headphones. You may think that your Audio-Technicas, your Sonys, or your Sennheisers sound good just they way they are now. But when you pair them with an external headphone amp, that's when they truly come to life. And if you ever wished your headphones had better sounding bass, or simply more of it, then you'd be very happy to know that the C5 amp will be your solution to your headphone woes. In fact, we think it's the perfect headphone amp for the job. If you thought you can achieve the same kind of bass tweaking with an amp like this using your digital EQ, think again. Of course we're going to come back to that shortly, but before that there are a few things you should know first.

Right now the most recent version of the C5 headphone amp can be had in either black or red anodized aluminum. It'll also set you back $189, considerably more than what you would pay for JDS Labs' guerrilla-style CmoyBB amp or NuForce's nano-sized MMP amp. Though there is merit to the C5's arguably expensive acquisition cost. It's a well crafted little pocket amp that despite its utilitarian looks, will put a big Joker smile on your face.


The C5 comes safely protected inside sealed anti-static wrapping along with a mini-USB charging cable and a detailed quick start guide inside a small cardboard box, which is a typical packaging choice for products you won't find sitting on a retail shelf. You'll also find a sheet with four clear adhesive rubber bumper feet to stick on the bottom of the amp for traction.


Without these rubber stick-on feet the C5's bare metal body will easily slide around on top of a table. So it's definitely a good thing they were included. What you won't find is an audio cable, so you should keep that in mind before picking one up. It's a shame that at this price you're not getting a simple audio cable straight out of the box. 


On one side, and accented by a user-removable brushed metal plate, are the C5's mini-USB charging port and power on/off switch. The C5 will not serve as a DAC when connected to a computer through USB. It can only be recharged unfortunately. If you are looking for an all-in-one package, there is the C5D, which is JDS Labs' headphone amp and DAC all rolled into one small C5-like portable package. But of course it's also going to cost you more than the C5 will at $249.


On the exact opposite end are all of your audio adjustment controls, ins and outs. On the far left is where you'll be plugging in your 3.5mm headphone plug, next to it is a little LED status indicator (solid green means the device is powered on, a blinking green light indicates low battery and a solid blue light will turn on when the unit is being charged). Right after that is where you'll find the C5's "pièce de résistance" - the three-level bass boost toggle (low, medium and high), followed by a 3.5mm audio source input and finally a volume adjustment toggle wheel, which also doubles as the dual gain level control (high or low - default is set on high) when pushed in. That's all there is to it. In a perfect world I would have liked these configurable controls to be more precise in the way the function in adjusting a certain value using fluid knobs that could give the user more control over the way things increase or decrease instead of pre-stepped toggles. That being said, it's important to note that you can change the volume gradually by holding down the volume toggle to the right or left.


I'm honestly not thrilled about the C5's aluminum-made enclosure. Yes it's a more permanent and more durable than JDS Labs' CmoyBB and the bead-blasted surface finish is nice, but it still lacks a touch of refinement around the edges and where the two end plates screw into place. It reminds me of an external hard drive enclosure you can buy off of eBay for next to nothing, which isn't flattering. I'm being overly critical about it even though it actually isn't a poorly built portable amp, and is acceptably good looking, but I would personally want more attention to detail when I'm paying as much as $190. For example, the plastic volume toggle is not acceptable at this price. It seems out of place, cheap and simply not very nice to use compared to a machined metal control knob you get when paying just as much for FiiO's sleeker E12 Mont Blanc amp. In comparison, the C5 has a more basic build quality and design. Still, it's what's on the inside that ultimately makes the most difference when time comes to hit the play button.

Unlike FiiO's E12, JDS Labs' C5 is made in the USA, has better battery life and is smaller than both an SSD and the E12, which is great because it fits in your pocket better than your smartphone does. You can toss it in your laptop bag if you're carrying a cable with you and you're good to go. You'll hardly even notice that it's there.


The difference between the C5 and the inexpensive pocket-sized CmoyBB is perfectly clear from an outside prospective. Things are different on the inside too. The CmoyBB isn't made for sensitive headphones and in-ear monitors, uses a user replaceable 9V battery and has limited sound configuration. While not as powerful as JDS Labs' O2+ODAC, the C5 is a more powerful and better made version of the CmoyBB with a built-in rechargeable battery that can last up to 14 hours, and offers more bass control as well as gain adjustment.

In addition, the C5 also features a cleaner audio output when using sensitive headphones thanks to its reference class hardware architecture that minimizes signal noise and delivers smooth volume adjustments. I haven't experience the same degree of low-volume noise when using the C5 compared to the CmoyBB. It runs very quietly even when nothing is playing. In fact, I haven't been able to pick up any noise using the C5 at normal listening levels. It's only when you really turn up the volume that you'll hear a very faint signal noise. Though to be fair it's very smooth and delicate. In terms of audio performance, there's no competition. The C5 sounds a lot better than the CmoyBB. Period. It has smoother sounding, thicker and more powerful bass – as well as more clarity injection.


From my experience using the C5 amp for a little over a week now, the performance I was able to get out of its 1200mAh-sized battery is more than acceptable. Having gone through quite a few cycles now, I do wish the battery life was a bit better, particularly when putting the C5 to its fullest using its highest bass boost level at moderately high volume output (or so I think). I was not able to get around to the claimed 14 hours during my testing, but instead roughly 10 hours - which is right about what you'll squeeze out of the FiiO E12. That should be enough to last you through the day if you're listening preference is similar to mine.


As mentioned earlier, the C5 offers three levels of bass - low, medium and high. The first will marginally improve your bass, the second will noticeably make a difference in the bass performance while the last setting will drop your jaw and blow your socks off with incredible deep bass you never thought you’ll be able to experience with your headphones. The highest bass boost setting on the C5 is indeed worthy of the legendary title, but in some cases it can be a bit too much, and I do love my bass. If you’re an addict, a true basshead, then this setting will make your brain vibrate and your plums tingle. Now it all comes down to your head gear and how capable the drivers are when introduced to more power than usual, but even Apple’s lightweight EarPods come to life when driven by the C5.

To truly put the C5 to the test, we gave it the seemingly difficult task of driving (amping) the least expensive and most bass-lacking in-ear headphones at our disposal - the Apple EarPods. That's right, we wanted to start with the basics straight out of the box, and what better way to put JDS Labs' legendary bass boosting engineering to the test than to pair up a pair of inexpensive earbuds with virtually no sound isolation with the C5 and its promising audio-enhancing capabilities. The end result? A night and day difference in audio performance, as expected. Without resonating bass, the EarPods were an outstanding pair for headset use. But with the C5 hooked up, the EarPods were given a brand new identity. One that shares a similar characteristics with higher-end in-ear headphones. The EarPods already has terrific clarity and a pleasing high-end, but all the needed was a slap of rich bass to make people want to use them more. I can definitely say that the C5 is more than capable of driving a delicate pair like the EarPods without distorting them, yet completely transform the way they output light-sounding audio, but instead allow them to deliver insanely impressive bass along with that fresh clarity their known for.


From a regular $29 sounding earbuds, the C5 makes the EarPods sound as if you were using a much more expensive set of in-ears allowing them to shine with their brilliantly clear sounding highs, but with the much needed addition of deep resonating lows and polished mids. I think that it’s important to note that although the C5 is capable of introducing a much deeper, punchier bass - it does so carefully without distorting your highs and mids. It may sound overpowering, but doesn’t muffle or drown its friends in the process. I may not have the most experience in using amps, but from what I was able to pick up it's that the C5's most noticeable improvement to your audio will without a doubt be the bass. It's all about that bass. And of course this will vary from headphone to headphone, but you'll also notice improved detail, a more lively midrange surface, and of course much improved deep lows.


When it comes to hook everything up, there are a couple of ways do go about it. If you're looking for an on-the-go setup solution or simply don't want to use any additional cables other than your headphones, you can use this ridiculously small interconnect connector that JDS Labs will offer soon as an optional accessory. It is literally the shortest 3.5mm to 3.5mm cable you'll ever see. Now although the angled connector plugs are relatively slim, they won't fit every protective case that you may be using on your smartphone or iPod. This type of interconnection solution is best used with a device that isn't much bigger or thicker than the C5 itself.


The two will need to be used as if they are one device in a back-to-back arrangement like you see here. It's definitely not for everyone as it can make using your smartphone somewhat difficult.


Next, you have two other interconnect cables you can use to connect the C5 up to your audio source being that a computer or a tablet. There's the 4-inch short FiiO L2 interconnect cable, which will not give you much room between your amp and your audio source, but it will be a cleaner setup with less cables in your way. The second cable that JDS Labs offers is this nice and thick, durable cable with thick metal connectors which gives you more flexibility to place the C5 where you want it to be. Despite its thickness, the cable can easily bend like well cooked spaghetti. This 3ft-long iSimple cable has 24K gold plated connectors, but they're too bulky to fit into protective cases and other tight port openings. They do work perfectly with the C5's input connections though.


The only thing I dislike about this particular cable other than its bulky plugs it's that it has metal connector casings that can be unscrewed for access to the connector joint itself. And no matter how tight you screw them on, they eventually come lose which is very annoying. We would recommend a different inexpensive cable like the Mediabridge cable, which has slimmer case-friendly metal connectors and is available in a few different cable lengths as well.


I don't only use the C5 with my iPhone, MacBook Pro and iMac, but I also find myself using it with my PS4 while I'm gaming or just watching a movie. Because I use non-PlayStation supported headphones, I can hook in the C5 to my wireless DualShock 4 controller and then I'm able to control my volume more coincidently. I can also get higher volume levels compared to the weak volume output of the PS4/controller. It works just as well as it does when you're using it with other audio sources. The C5 will of course enhance the audio coming out of your console with your bass preference.


The C5 Portable Headphone Amplifier unlocks that hidden audio goodness in every headphone with a formidable bass injection

JDS Labs has done it once again. The C5 is a great little portable headphone amp with insanely good bass boosting capability, powerful and clean high quality audio output you wouldn't want to be left without the next time you pick up your headphones. Hearing how awesome my Audio-Technica M50x headphones sound when powered on by the C5 amp, the experience simply isn't as enjoyably engaging going back. And going back isn't something I plan on doing any time soon. It's not a cheap piece of audio gear, however, if you like deep impactful bass and can't get enough of it out of your current setup, then the JDS Labs C5 portable headphone amp is a solid choice. The C5's long battery life, multi-step bass injection, excellent signal to noise ratio and pure unhampered audio enhancement with virtually all headphone types make it a compelling portable amp we have no trouble recommending. The C5 also wins an Editors' Choice Award for being a gadget we actually like using on a daily basis.