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April the first, but this article is for real as I really lack the creativity to throw a successful April Fool. Now let’s get on to the review. I have mixed feelings about the new JDSLabs C5 amplifier. While there are improvements, going from the older C421, my ears still find the more laid back sound of the C421 to be more preferable. Though that may just be a personal thing. Anyway plus and minuses are normal in a review, so let’s get into the details to get a better picture of the new amplifier from JDSLabs.
A Digital Volume Control
Apparently one of the aspects about the C421’s performance is that the analog pot is not ideal for tracking stereo channel in low volume levels. Well, what analog pot is? The solution has always been to either use a different headphone/IEM that’s less sensitive, lower the gain of the amp, or switch to a stepped attenuator. Recently portable amp manufacturers tend to prefer digital volume controls, first seen in Ray Samuels’ The Shadow.
Sound Observations
The digital volume control implemented in the C5 eliminates not only the channel tracking problem, but also the sound is noticeably cleaner, less grainy, and with a tad larger soundstage. I didn’t really feel that the jump in technicalities to be huge over the C421, but they’re there on careful listening. A word on the soundstage, despite the C5’s being a little bigger, the more forward sound of the amplifier does sort of mask that fact. On the C421 with its more laid back sound, it’s easier for me to pick up an impression of a big soundstage, whereas the C5’s more forward midrange sort of put everything into a more focused stance and so I don’t usually associate the C5 as being large sounding.
The sound is more forward, but not Apex Glacier or Fiio E12 forward. This is one of the more forward sounding amps in the market, and a slight departure from the JDSLabs sound signature that I’ve heard on the CmoyBB and the C421. Upper midrange is definitely more relaxed on the C5 than compared to the Fiio and the Apex. However compared to the C421, the entire midrange is pushed more front and the resulting sound that you get is more upfront and with a slightly faster pace than the C421. It does make for a generally wider bandwith sound, as I can play faster-paced music better with the C5 even with something laid back like the HD650, than I can with the C421. Though the presentation is forward and the pace faster, the C5 maintains its composure well. The amp never gets shouty, honky, harsh, or bright in its presentation. At really loud volume levels, however, the amp does lose a significant bit of its composure. It loses control on the dynamics, and the upper mid starts to break lose, even as I’m using a relatively normal 300Ω Sennheiser HD650. For reference the C421 holds things better than the C5 at really loud volume levels. This sorts of puzzled me as the C5 is supposed to have the same power output as the C421.
I noticed some parts of John’s C5 blog writing about the fantastic THD+N numbers of the C5 when compared to the C421 and even to the Objective 2 amp. I really don’t know how superior THD+N numbers are supposed to translate to the audio waves picked up by my ears, but I don’t think that the C5, as much as I dislike the O2, can compete with the clean black background sound I hear on the O2 amplifier. The C5 is more musical to my ears, that’s for sure, but I wouldn’t really compare its technicalities to the O2. Likewise in reference to the C421, yes there are slight improvements on the technicalities as I’ve written earlier: slightly cleaner and less grainy, but it really is not a big jump over the C421.
A New Bass Boost
In between these mixed feelings, I do have a big crush on the C5’s bass boost toggle. This is not the average bass boost switch. What I’m hearing is a big gain in bass levels, yet with things still well in control and with the bass boost extending quite low to almost sub-bass region. It’s an extremely nice bass boost, easily the best in sub $200 amplifiers. What it does is not just bass quantity, but rather an extra HD650 effect to the already weighty HD650. You get an even fuller sounding lows, adding weight and bass fun into the sound, without the clouding of the midrange section. Again, even with the HD650, I keep the bass boost switch on, all the time. Music is so much more fun that way.
End Words
The biggest upgrade, I feel, is the enclosure which is now extremely solid and refined. Even with the red color far from being my favorite red color, I still dig the look of the amplifier tremendously. That thick machined faceplate really screams premium, and I wouldn’t be surprised if JDSLabs was to price this upwards of $220 (the C5 sells for $189). It really is a big step up in terms of build, and that is a big deal with portable amps, as much as you want your smartphone to have a great build quality.
However, spending time with the C5, I really haven’t been able to really blend with the sound, as much as I did with the C421. I know the sound direction that it’s going for, and it’s done a pretty good job with the tuning. More forward, slightly faster pace, wider genre bandwith. It just didn’t hit the homerun for me, though I’m not so sure if that’s John’s fault as the amplifier designer or it’s just my ears that prefer more laid back sound. I do think that if the C5 is going to be a more forward sounding amp, it needs a faster, tighter, and punchier bass section. Perhaps an AD8066 or an AD797 type of a sound. As you read through the review, you should be able to pick up positive points about the C5. Had I created a positive/negative checklist, the C5 should be a clear winner over the C421.





Adli Hakim
Nice looking photos, as always. Mike, can you compare the C5 and C421 for IEM use? As a full time IEM user, I’m wondering if C5 will give me significant upgrade compare to my C421. Cheers. 🙂
Guest
MIke, can you compare C5 and C421 for IEM usage? As a full time IEM user, I’m wondering whether the C5 would give me better performance compared to my C421. Cheers. 🙂
Mike
Thank you. Aside from the sound differences I wrote, you get a much more precise tracking of the stereo channel on low volume levels.
Adli Hakim
Thanks, Mike. Got problem with Disqus system.
Dave Ulrich
When you talk about it losing control at high volume, do you mean the amp’s volume turned up or loud passages in the music?
Mike
Amplifier volume turned up. Thanks for clarifying.
Andre
Great job on the review Mike. I’ve been waiting to hear your thoughts on the C5. Have you guys had to the chance to pair the Headstage Arrow 4g with the HD650’s and if so how does it compare against the C5 paired with the 650’s? Which do you prefer?
Thanks
Mike
The character of the arrow is quite different. I think it’s based on the AD8397? Opamp which is a more forward sound with a good tight bass but less spacious than the OPA2227.
The 3G Arrow I feel is the better amp of the Arrows. It was darker yet felt more coherent throughout the frequencies. The 4G had more treble that felt forced and feels dryer too.
I’d take the 3G arrow over the C5, but the 4G, I’m never a fan.
Andre
Good to know, I was choosing between the 3g and 4g and this just helped me out quite a bit. I’m moving away from my e17/e9k to something a little different. I’m going to try the USB Sabre DAC from HIFImeDIY and try either the Arrow or a Fournier Tube amp I found on eBay. The C5 was an option and seems like it is a great little amp but I think I’ll go in a different direction for the time being. Thank you again for the help.
Mike
You’re welcome, Andre
Benjamin Benito
How does C5 compare with E07k?
Mike
Benjamin,
The E7K has a signature more similar to the C421, though not quite as refined. The bonus with the Fiio is that you get a DAC built in.
AudioFreak
How do you compare it to the o2?to me the c5 lacks dynamics and soundstage is smaller compared to the o2
Mike
I don’t have the O2 here but I agree with those two points you mentioned, based on my memory.
François Côté
Hi Mike, I own a pair of Beyer T70 and I hesitate between the C421, C5 and the Fiio E12 to drive them properly… I’m searching for a more dynamic listening, just to gain up a bit the low frequencies, without destroying the balance of treble, highs and soundstage. Thanks
L.
The T90 sounds just right for you. Actually the C421 does lift the lower frequencies. The T70 is fairly easy to drive so you don’t need the E12.
Dave Ulrich
Not sure you can get the C421 new anymore.
Mike
Yes it’s discontinued
François Côté
Thanks for the comment! So for boosting the lows well for a pair of beyerdynamic semi-portable cans, keeping all good sounding and even improving the clarity and soundstage from an ipod, I can consider the C5? I also listen to low quality formats.. Which by the way sound awful with these cans without an amp
Mike
Definitely, yes!
Yi Wen
Hi Mike, very nice review! I just ordered a C5. Too bad silver ones are not available so I went for a red one. Preference wise, I found OPA2227 a nice sounding op amp. But comparing to OPA627, 2227 is not really that enjoyable. I sometime hope that JDS could a little open to some pricy op amps.
L.
Maybe they will in the future!
Ben Stewart
Hi Mike, I just want to ask, which one is better JDS C5 or Fiio E12? Thank you..
Ben Stewart
Sorry Mike for your information i need them to drive my Sony MDR-1R and will be pair with I Touch 5G
L.
if it’s hard to drive: E12, if not C5
Ben Stewart
Thanks guys, i think i will go for C5
L.
You won’t regret it
Mike
Hi Ben,
What Lieven said.
I think the 1R is quite easy to drive and the C5 should be better for it.
L.
I just received my brand new C5, it has a blue-grey finish. Very nice. The digital control is very good, finally no more channel imbalance at lower volumes with my iems. The bass boost is awesome and the high gain isn’t needed and won’t be used. I’ll see what I can write extra after a thorough listen
Dave Ulrich
So L, how has it been treating you?
L.
Pretty good. I completely agree with what Mike wrote about the C5. It’s good but besides the volume control which is excellent for iems, the tonality of the C421 was more addictive. Don’t get me wrong, the C5 sounds good too, but I’d like to have a mix of both. I have loaned out my C421 to CE, but they haven’t gotten back to me about it.
Dave Ulrich
I’m thinking of it though. All of my amps are laid back. Something a little more forward would make a nice change.
L.
The C5 isn’t really “Forward” sounding like other amps can be. I personally would not call it a forward sounding amplifier if you ask me, yes it is more forward sounding as the 421, but not compared to other amplifiers. Am I clear enough?
Dave Ulrich
Crystal, sir!
John Seaber
Thanks for the impression, L. I followed up with Mike after this review went live. C421 had a high output impedance, so it produced unique behavior depending on the headphones to which it was paired. C5’s output-Z is more ideal, and this definitely affects tonality. Good or bad? That’s up to you guys. Customer feedback is definitely more positive with a lower output-Z, so we have no plans to go back to the c421 sound.
Mike
Thanks John
Roy Bonjovi
compare it to the E17?
Mike
Pure amp vs DAC/Amp
Roy Bonjovi
so i assume the c5 is better in terms of sq?
Mike
Yes but if you’re playing from a computer the Fiio will yield a better sound
Roy Bonjovi
I see. Thanks for your fast response. I think the C5 would suit me better then cos I only want a portable rig and therefore I won’t use a com.
Mike
That’s right
harry lennon
which one shud i get?e12a or jds c5
Headfonia_L.
Depends how you’ll be using it
lenin reddy
which will be a better choice for HD650 : Jds labs C5 vs Fiio E12a Vs cayin C5
Im looking for a bassy and more sparkly one without disturbing mids on hd650
Headfonia_L.
The E12A wasn’t developed for full sized headphones. I don’t have the Cayin C5 but the C5 or Cloud nine are both good. I do advise the Cloud Nine over the C5 as it has a better SQ but it does only work with 9V batteries