My solution to overheating DAC dongles

If you like a little bass bump but with an overall neutral sound sig then here’s another option…!USD!US%20%2435.00!US%20%2435.00!!!!!%40211b88ef16813012839445114e0c79!12000030305713156!sh

Sorry i’ll pass this one, too expensive for me…

Got the JM6 Pro, it came in a neat package albeit with a bit too much plastic for my taste: foil wrapped cardboad box, plastic tray inside holding a tiny warranty leaflet and the dongle itself presented in a silky matte plastic bag and having a dust cap over its USB-C.

Sounds fine, has the powah, it was blasting my ears when I first plugged it in with 16-ohm headphones, system volume at max and YouTube volume at about 10%. Sounds good, has stereo separation, I will have to think of a setup to A/B it against the Hiby FC3 and the FiiO BTR3 because the JCally is the first one I got that only has USB-C male, and I wasn’t ready for that (still not using the new phone, that one needs more work).

One thing that worried me at first was that the headphone TRRS jack didn’t go all the way in, it left about half the S terminal outside the device. Turns out the corresponding springy metal contact is right on the edge of the JCally’s connector and touches the sleeve just fine, everything’s aligned, I get stereo music and a working microphone signal, everything works as intended, I guess they just wanted to make it as smol as possible or something.


Looks very sweet! I’ll definitely look forward with the updates

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OK, so I got more adapters and I could do the first round of A/B listening, JM6 Pro vs. FiiO BTR3. Headphones = Hifiman HE-400i pre-2020.

The BTR3 connected as an inline DAC to the phone I had to turn up to 100% + digital volume to 100% just to hear it loud enough to understand everything, and I would’ve still liked an extra step. When running on battery + Bluetooth it needed 80% digital volume for the same loudness, while the JM6 Pro needed 60%, so it was the most powerful of these 3 options and gave me some actual headroom to turn it up to disturbing levels.

Correspondingly, there seemed to be better dynamics and a more realistic/convincing presentation of vocals and natural instruments on the JM6 Pro, but not a big improvement - it could’ve been placebo from just knowing that it goes louder at max, or it was real but just a small improvement.

When I got to some busy electronic tracks with sizzly and sparkly things going on way up top I could hear the BTR3 does better, and it’s not placebo, it’s definitely more crisp and presents more “things happening” at high frequencies, where the JM6 Pro is veiled. (Can’t say how high that was, but I think my hearing currently rolls off around 14k, so there must be detail differences already below that, we’re not talking 20k here.) But I didn’t notice any of that on tracks with vocals and natural instruments, so for those the JM6 Pro might still be preferable due to the dynamics. I just like treble detail much more, so if there’s no practical constraint forcing my choice, for general/eclectic listening with Shuffle enabled I would still pick the BTR3. YMMV.

I couldn’t get both channels connected or any audio in some cases because I didn’t push the headphone jack all the way into the JM6 Pro. I worry that that female connector will lose the ability to hold the jack in position after not a lot of usage, due to this lack of “clickiness” at the end when you reach the right position. We’ll see.

Next I want to A/B vs. the Hiby FC3, but first I have to do Hiby FC3 vs. BTR3 because I rushed to put the Hiby up against much bigger boys to see if it’s a giant killer, and I was quickly brought down to Earth in disappointment (lack of power, lack of dynamics and realism of bass and low vocals vs. the Oppo HA-2). :slight_smile:


Very awesome! Thanks for such a long write and in depth testing. I see this as a good fit for my future AKG 701. Cheap dongles are getting so good dang, what a time to be alive for audiophiles.

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Did that. No shot. It barely has more power (goes 1-2 dB louder maybe) and loses completely on upper extension and detail. If I only had these two I think I would never touch the JCally. But it gets worse, unfortunately:

Yeah, that happened too today, sorta. I wanted to give it another shot vs. the BTR3 but used a different cable with a microscopically different 3.5 jack this time, and I couldn’t get stable stereo contact with this one - it would keep sliding out and losing the right channel. :frowning: This thing is gonna be a PitA with any 3.5mm it doesn’t “like”. Plus… I tried to play music from web players in the browser this time, and every time I wasn’t playing anything for half a minute or so it would start some horrible buzzing and regular popping sounds like I’ve never heard out of any DAC hooked to my phone ever.

Will check if does that with anything other than my estat system, but the female jack is already a dealbreaker and I can no longer recommend this dongle (I mean in theory one could replace just the 3.5mm connector, but getting the new attachment point to be durable and not have the operation blow up the total cost… yeah nah).

I still believe the CX31993 is likely a great chip, it just doesn’t seem to have found its best implementation in this JCally JM6 Pro device. Back to the drawing board finding something cheap to serve as a backup for my Hiby, I guess. :face_with_diagonal_mouth:

Noo, not really, those are damn hungry, they need a good 250 mW to sound good, and that’s into 62 ohms, not 32. You basically need at least double what the JM6 Pro can put out, and that’s without any headroom to make sure you’re running the amp at its cleanest.

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Again, thanks for the long write!

Bummer, i bought it too. It has some issues with the female jack, can confirm. In my case my KZ cable just didn’t “click” properly. Ah well, it stays forever with my Samson SR850, i guess. It has “crunchiness” to it if the tracks gets very busy, at times cymbals sounded harsher and uncontrolled like distortion. Didn’t sound clean compared to my frankenBasso.

I also have some noise issues with it too, in my phone it quiets down with airplane mode (still hissing). In my computer tho, it has ground noise if i touch my feet to the floor (even louder with metal IEM like MD Aria). As if it has no noise attenuation if it doesn’t play anything, because it also happened to my old cheap unbranded Aliexpress DAC too.

Jesus Christ 701’s are hungry.

Yeah, I think that MAX chip is really degrading the DAC’s output, even though it ups the power. Classic trade-off. Hiby also did this in the FC4 vs. the FC3. Clean signal? High power? Low price? Pick 2. :stuck_out_tongue:

Yep, 102.5 (105 advertised) dB/V is not a lot of sensitivity even if it seems like a lot because it’s past 100. And it’s on double the impedance vs. usual.

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OmegaLUL, I thought let’s try it one last time with every jack I have, just to be sure I’m not crazy here, and right now every, single, one, fits, and clicks securely into place, with no part of it left outside. :exploding_head: Including the one I earlier today found to be the first one that couldn’t maintain a R-side signal. Maybe this connector just needed some break-in first? I can’t even.

So since the mushy upper treble and the noise susceptibility are not dealbreakers, I’m keeping this little bastard after all, it’s gonna fit exactly the role I had in mind for it. :sweat_smile:

The EM noise also went away once I got the full-click connection. These really were the high bang-for-buck that Andy.EF had made them out to be in his review, it just took some fiddling to find that out. (That’s the second time I thought I caught Andy giving bad advice and being a bad reviewer, only to be shortly proven wrong by direct experience with the device. :sweat_smile:)


hold my beer @SKC56


Now THAT is proper heat dissipation

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All that’s missing is a random fan mounted on top of that by driving self-tapping screws between the heatsink fins. :smiley: That’s how I stopped my Pentium III PC from crashing in games due to the passive-cooling-only 3DFX Voodoo 2 card always overheating. Stuck a small case fan on there with only one screw at one corner → stable system, gaming for hours liek a baws. :sunglasses:


@SKC56 Thanks for the inspiration btw - I remembered I had a dead GPU with a heatsink to spare, thought might as well…

@abm0 lol Touche - I just pulled it off my otherwise dead to rights Nvidia 7300GT lol.

But this should serve fine as passive lol.

Beats me though why the Tone 2 Pro gets hot - even with just DAC duty. Well, no more.

Course Samuel Jackson would be so pissed: “Say it’s a portable DAC again, I dare ya, I double dare ya mo****”


This. This killed me :rofl:

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