[bzippy]

There is surprisingly little talk comparing these two amps, and no dedicated threads that I found, so with the following wall of words let me be the first. Let’s hope this starts a fun debate.
 
 
I've been very happy with the E12 v1 for about a year now and during our time together it has survived a number of tough shootouts, including the E12 production model, the E12A and the Cayin C5. But I recently learned about the JDS Labs C5, which looked to have everything I like, including enough power to drive my HD600s, flat frequency response, variable bass boost, good battery life and affordability. So let's get into it . . .
 
All testing was done with line out of the FiiO X3 and my HD600's, and both amps set to high gain. Volume matching was unfortunately done by ear I’m sorry to say, but that’s all I can do. But it’s really not that bad because I just set each amp to the volume that I would normally listen and then make my judgements, so that seems pretty valuable imo. (more on volume matching in the detailed review below)
 
I have also been asked to disclose in all my reviews that I have mild tinnitus, which is a constant ringing in my ears at about 4 kHz that causes me to hear somewhat less in this frequency range than other folks.
 
 
Hi end and sound stage
The first thing that surprised me is that the JDSL C5 has a rounder top end which gives it imo a more forward presentation and less apparent space. This was obviously a surprise to me since everyone -- and I mean everyone -- says the FiiO sound is among the most forward and narrow of amps, and that the C5 blows it away in this regard. I am starting to think that soundstage is mostly a function of frequency balance, especially the balance of mids and highs, but lows also play a role. Comparing these two amps closely I heard a peak in the high mids / low treble in the E12 that I hadn’t really noticed before. The C5 on the other hand was more neutral and imo a lot more natural. The result is that there was absolutely no harshness in the high treble sounds in vocals (“s” & “t” sounds) nor in cymbals, yet still had enough high sparkle to sound realistic and not the least bit dull or veiled. In contrast, the E12 definitely had the tendency to cause me a bit of a wince every time a track had a sudden and/or prominent sound in these frequencies. In addition, I now heard a bit of graininess in the E12 that I hadn’t noticed before, which is a verification of everyone’s claim that the JDSL C5 is clean, clean, clean. Simple productions like a solo singer with a single instrument were absolutely captivating and realistic with the C5. I had no idea what I was missing with the E12. So bottom line: for rock, pop music, especially the more subtle & laid back stuff (indie, acoustic, jazz) the C5 is the clear winner for highs.
 
Then on to some classical music (only about 10-20% of my listening habits). I heard all the same things as with pop & rock tracks but my reaction was completely opposite. That upper mid / low treble peak in the E12 no longer came across as harshness but rather added life, air and space, especially with strings and woodwinds. This was initially disappointing because at this point I was so wowed by the C5’s ability to beautifully & naturally reproduce popular music that I had already decided to keep the C5 and dump my heretofore beloved E12. Classical music was now giving me second thoughts. But a reconsideration of volume matching brought this all into perspective and I’ll continue on this point after some thoughts on bass frequencies.
 
 
Bass, Bass Bass
There are two primary things I noticed comparing these two amps: (1) the unboosted low end is a bit more prominent and punchy in the C5 than the E12. As a result, I am speculating the E12 rolls off a bit down there while the C5 stays flatter. And (2) the E12 v1 bass boost is such more subtle than the Medium bass boost setting of the C5 (the C5 High bass boost setting is thunderous and way too much for me in all cases). In fact even the Medium bass boost on the C5 is often too much for me because it reaches up a bit too high and results in an overall thickening of the presentation, including the very low end of solo singers’ voices. Generally I like a more subwoofer like boost for my HD600’s. But that is highly dependent on the recording, and some stuff definitely benefits from the C5 Medium boost (eg. older recordings and much of my classical music). As we all know the E12 v1 bass boost is very subtle and confined to the sub bass region. It is so subtle in fact that I am tempted to say that it merely brings the E12 low end up to the level of the C5 unboosted low end, albeit still maybe just a tiny hair more. Anyway I was finding that with most recordings I was damn pleased with the C5 boost off. In contrast, the E12 bass boost was an “always on” deal for me, yet it still left me wanting a bit more for many recordings (again, this is the nature of the HD600’s). To make this more clear, here graphically is the level of bass impact I heard:
 
unboosted  E12 v1 -->(very small step)--> unboosted JDSL C5 -->(very small step)--> boosted E12 v1 -->(big step)--> JDSL Med boost --> JDSL High boost
 
 
Mids
Mids have always been a tricky for me to quantify because, at least for me, the prominence of the mids is so highly dependent on the lows and highs. Case in point: in the typical Treble Bass eq circuit, it’s very common to change the mids by adjusting T, B and volume levels. I can only say that I did not hear much difference in mids between the two amps and it did not really factor into my decision. Neither amp was scooped in any way, as one would expect from these two excellent audiophile design houses. (the glorious mids of my HD600's get much of the credit here, I imagine)
 
 
A few words on volume matching
I am more and more convinced about the primary importance of volume matching in matters of critically listening and subtle differences in equipment. So after going through all of the above I reconsidered my volume matching technique because I realized that I had been setting comfortable listening levels on the E12 based mostly on my tolerance for the high frequencies, which are a bit more piercing with this amp. The result was that the mids and lows of the E12 were being underrepresented, which gave an apparent widening of the sound stage. Matching volumes based on more middy passages I realized I could raise the C5 volume a bit, which revealed more high end presence and life of strings & woodwinds, widened the stage some and also raised the low end. Overall I now heard a more rich, full, & wide sound out of the C5. I might still call the C5 more "forward" than the E12, but I am open to more of this discussion.
 
 
Ouput Power and Battery Life
Everyone knows the E12 is a monster, both in power and also in the battery life I've experienced. In high gain mode I never set it much above 25% of the volume knob sweep. Since so many report the JDSL C5 to have more than enough power for my 300 ohm Senns I just accepted this as fact. Due to the C5's blind digital volume adjustment, I have no idea how much of the unit's volume range I use but it seems fine so far. I could get it plenty loud even in the C5's low gain mode, but just to be sure I keep it in high gain mode. C5 battery life is probably a bit less than the E12 according to my reading but I have not experienced this nor done any testing. It seems perfectly acceptable at least, but maybe even as good as the E12 -- I can't say for sure. Neither has a running battery level meter, which would be nice, but oh well. One thing's for sure, they both last a good deal longer than the Cayin C5 I had for a couple weeks.
 
 
Bottom Line
I am still experimenting, especially with volume matching, but do I prefer the C5 enough to make my decision and have put my E12 v1 up in the classifieds here. What I lose in string airiness is also a gain in realism & smoothness in non classical music. With its cleaner sound, the small extra bit of low end in the unboosted mode, and the overall more natural & engaging sound, the C5 is the clear winner for me. I have to assume that my tinnitus has previously served to smooth out some of the harshness and grit of the E12 up to now and without that I might not have kept it so long, but who knows.
 
Also worth noting that most of these impressions came from a good number of intense critical listening sessions. When I first received the C5 I was a bit disappointed because I really didn’t hear any significant differences from the E12. It was only after living with these two for a solid week that I am finally start to notice all this stuff. The differences are very subtle and these amps are both really great. The E12 served me well for a good, long time and I definitely have some reservations about giving it up. But off it goes just the same.
 
 
If you made it all the way to the end, thanks for your patient reading! I hope this was useful to some folks.
 
- Brian

 

[Sixpence]

Very nice review. What you've written here echoes all the other impressions of the c5 being the better amp overall, while the e12 has a better bass bump.

You are right that there aren't any dedicated threads to these two, but that's due to the quality of the C5. I know there was a bigger debate between the C5 and the Cayin C5. I'll post some links for your reading regarding that.

How long did you have the Cayin C5? Are you able to make any notable comparisons between it and the C5? I recall reading that if the Cayin had the bass bump like the E12 has it would be the best portable amp in its range.

Currently I'm considering the C5 and the Cayin, I do admit that the Cayin is more powerful for my needs, but I wouldn't put the C5 out of the question. What say you between these two budget amps?

 

[bzippy]

Thanks for the kind words. I'm glad you got something out if it.
 
I assume that the "bass bump" you're referring to means the bass boost. Perhaps I wasn't very clear on this point because I do not think the E12 has a better bass boost for my needs. What I tried to get across is that in unboosted low end of the JDSL C5 had more impact than that of the the E12, and further it was damn close to the E12 v1 with bass boost on (the v1 bass boost is very subtle). I found that for many of my recordings I craved a bit more thump than the E12 v1 boost offered, and for those recordings I do like that i now have the option to kick it up a small notch by engaging Medium boost of the JDSL C5. So I am definitely giving the nod to the C5 bass, both in unboosted and Med boost modes. Just wanted to be perfectly clear on that. (though I can't see myself ever using the C5's High boost mode). But if I may be super picky for a moment, my ideal would be to lower the frequency of the C5's bass boost peak down to around the 40 Hz range rather than the apparent 80 Hz that it currently seems to be, and also make the right side slope a little steeper so as not to bleed into the high bass / low vocal range as much. As I recall the E12A IEM amp had a bass boost that was kinda just right for me, but it lost out to the E12 v1 in too many other ways, most notably a lack of overall liveliness & impact probably due to insufficient power to drive my HD600s.
 
And now to your C5 vs C5 question. I would like to have the Cayin back to compare directly to the JDSL C5. All I can do for you right now is to compare them by trying to connect my findings when comparing the E12 to the two C5's individually, which may or may not be valuable. Rereading my post comparing the Cayin C5 to my E12 v1 (here's the link), I described a number of things that made me prefer the E12 overall. One major issue was that the C5 boost was just too heavy handed and therefore unusable for me. That alone was a deal breaker. I did find the Cayin C5 sound stage to be wider and more spacious, but this may have been due to the fact that it was a bit brighter than the E12 and also seemed a bit relatively recessed in the mids to my ears, especially with vocals and guitars. I also reported hearing very little difference in the amount of unboosted bass impact between the Cayin C5 and the E12. But now that I better understand the importance of careful volume matching, I wonder whether I might revise/refine some of my opinions in that post. I don't know. I only had the Cayin C5 for about a week. All that said, I do still trust my initial findings enough to believe that the JDSL C5 suits my ear better than the Cayin C5. The JDSL C5 seems to mate so well with rest of my rig -- it just sounds right. So I probably won't ever bother to acquire another Cayin C5 for verification but instead I intend to simply lose my self in the velvety sweetness of the JDSL C5, well until the honeymoon period wears off that is.
 
I am indeed interested in any C5 vs C5 discussions you found. I vaguely remember looking for this once and not really coming up with anything,

 

[Sixpence]

I actually cannot find the C5 vs C5 now. I'll take another look and edit this post.

I understand the bass boost concept you mentioned, in some of the comparisons, people mentioned if the C5 had the correct response from the bass boost (like the E12) it would be a perfect amp in this range.

You've put me in a vice grip here, both options are great, but the choice must come down to one. One last thing, do you miss the Soundstage of the Cayin compared to the C5?

 

[bzippy]

. . . One last thing, do you miss the Soundstage of the Cayin compared to the C5?

 
that's hard to say, maybe, maybe not. i'm not convinced i know what creates the illusion of space, but i'm guessing it has something to do with the amounts of high end and mids (assuming you're talking a clean amp and using high quality source material, both of which has been true in all the tests i've mentioned above). my reports remind me that i found the Cayin's mids (especially vocals) to be a bit recessed compared to the E12 and it was also a bit brighter. if these characteristics are indeed the reason for the Cayin's apparent wide stage then i happily take the trade off. so, no, i don't miss it. but again, i'd really love to get my hands on a Cayin again someday to conduct a battle of the C5's! if such a thread does already exist, i'm amazed it doesn't have permanent Page 1 status here.