[zg1984]

Hi all,
 
I'm using the JH13v2 out of a Fiio X5 2nd generation DAP. Unfortunately, I'm hearing some hiss. Not something one could notice during the busier parts of a song, but when there is a single instrument playing, it is pretty clear. All of my audio is in FLAC format, with some tracks in DSD, but the presence of the hiss overlooks this.
 
In by no means an expert in audio equipment; just a gut that enjoys high-end sound. With that said, I would really appreciate if some could, first of all, clarify this input/output impedance thing and its relation to the sensitivity of the headphones in use.
 
On top of that, what are the possible solutions to this? Which of those you think is the best one and why? It would be great to get solution from different price categories.

Thanks!

 

[HiFiChris]

That hiss is not related to the output impedance. Sensitive IEM + DAP without super good hiss performance + rather hiss-sensitive ears = audible hiss. Assuming that the hiss is not coming from the recording of course, but as I've heard some users reporting the same (hiss w/ X5k and sensitive IEMs), there is no reason to assume that it is mainly coming from the recording. If you still want to be sure, load an empty audio file on the DAP (it can be created with free software like Audacity) and check whether it's the same amount of hiss.

Two things I'd suggest - either a hiss-free source (the iBasso DX90 is hiss-free but has got at best average battery life of around 6 hours; the Plenue D has really good hiss performance as well but is rather loud at the lowest possible volume setting; the FiiO X7 is also said to be about hiss-free but I haven't auditioned or owned that one myself) or a hiss-free Amp that you connect to the X5k's Line Output (gain-reduced Leckerton UHA-6S.MKII for example; the Vorzüge Amps are also said to be hiss-free but unlike the Leckerton, I haven't owned or auditioned any of their products yet).
 
 
Hope that helped a bit

.

 

[zg1984]

Yes, that helped a lot - thanks!
 
I have a followup question. It so happens that a friend of mine own an iBasso DX90 (he uses 1964 V6's) and after hearing my Fiio X5 he decided replacing his DX90 with a Fiio X5. So the simplest and definitely cheapest solution for me is to just switch players with him. There is one small issue though - I also like the warmer more lively sound signature of the Fiio X5 (especially when combined with the very natural signature of the JH13s) over the more flat sound of the DX90. On the other side, I con't be at ease and fully enjoy my music with that hiss, so this got to go ?
 
My question is would adding an amp (the Leckerton UHA-6S.MKII look very good and would probably be my choice) to the Fiio X5 preserve its warmer sound while removing the hiss, or will the sound signature change?
 
Another small thing I'd love to understand, which might be a dumb question but I'll give it a go anyway: Does an amp has its own sound card and when connected to a DAP, the amp's card overrides this of the DAP? Or does the amp just post-processes the (analog) sound produced from the sound card of the DAP?

 

[HiFiChris]

  Yes, that helped a lot - thanks!
 
I have a followup question. It so happens that a friend of mine own an iBasso DX90 (he uses 1964 V6's) and after hearing my Fiio X5 he decided replacing his DX90 with a Fiio X5. So the simplest and definitely cheapest solution for me is to just switch players with him. There is one small issue though - I also like the warmer more lively sound signature of the Fiio X5 (especially when combined with the very natural signature of the JH13s) over the more flat sound of the DX90. On the other side, I con't be at ease and fully enjoy my music with that hiss, so this got to go ?

 
That would be indeed the easiest solution. 

The slight warmth is in most cases caused by a somewhat higher noise floor or THD spikes in the upper frequencies (not much but actually just very little). Also caused by "noise floor modulation", according to Chord Elecronics (i.e. no measurably flat noise floor but a preference of a certain frequency band). So in most cases, the subjectively perceived warmth comes at some disadvantages (hiss in most cases).
 
 

 My question is would adding an amp (the Leckerton UHA-6S.MKII look very good and would probably be my choice) to the Fiio X5 preserve its warmer sound while removing the hiss, or will the sound signature change?

 
It always depends on the source device and with most, the subjectively perceived sound will be really flat and neutral through the Line Out, and the final sound will be dependent on the used external amp. I assume the sound out of X5k's LO will be subjectively pretty neutral (my X3's is).
Anyhow, I perceive my UHA-6S.MKII as very slightly on the smoother side of neutral (stock configuration with gain reduction). Depending on at what volume settings you are listening with your X5k, I would highly recommend to ask Nick (the guy behind Leckerton Audio, a really nice person to talk to) for a gain reduction of between 10 and 30 dB (as the UHA-6S.MKII uses an analogue volume potentiometer, there will be some channel imbalance before the 9 o'clock position reached).
If you want to conserve that smoothness with somewhat organic and warm sound though, the iBasso DX80 + an external amp would be a good way to go (speaking of the DX80 and an external amp as the headphone out is quite hissy). The DX80 is one of the rather few devices that also conserves its smoothness, analogue-ness and organic-ness over the Line Out.
 
 

 Another small thing I'd love to understand, which might be a dumb question but I'll give it a go anyway: Does an amp has its own sound card and when connected to a DAP, the amp's card overrides this of the DAP? Or does the amp just post-processes the (analog) sound produced from the sound card of the DAP?

 
A pure amp won't have an internal DAC (= sound card) but only analogue amplification of an analogue source (connected over the Line Out of the source). If you are however using an amp with integrated DAC (such as the UHA-6S.MKII), you can connect it digitally to the source if it has a digital output (the X5k for example has a digital coaxial output and the Leckerton both a coaxial as well as optical S/PDIF input).

 

[zg1984]

That was really helpful - highly appreciated .
 
I think I'll give the DX90 another proper listening followed by an A/B test with the X5. If you're saying the warmth mostly come with the price of the hiss (which I'm not willing to pay), then I guess it's a matter of prioritizing.  Worst case scenario, I can always add the UHA-6S.MKII on top of the DX90 later on. My bank account just suffered the price of the JH13s, so taking it one step at a time sounds reasonable. What do you think?

A pure amp won't have an internal DAC (= sound card) but only analogue amplification of an analogue source (connected over the Line Out of the source). If you are however using an amp with integrated DAC (such as the UHA-6S.MKII), you can connect it digitally to the source if it has a digital output (the X5k for example has a digital coaxial output and the Leckerton both a coaxial as well as optical S/PDIF input).

 
Say I do get the UHA-6S.MKII, to which one of the usage option (analog amplification or using the DAC of the amp) you were referring to for solving the hiss problem best? 
I guess this relates back to how good is the DAC of the UHA-6S.MKII compared to the DAC of the X5 or DX90...
By the way, how does the DX80 preform in terms of hiss? Is it a newer product than then DX90? What are the differences in the sound signatures?

 

[HiFiChris]

  That was really helpful - highly appreciated .
 
I think I'll give the DX90 another proper listening followed by an A/B test with the X5. If you're saying the warmth mostly come with the price of the hiss (which I'm not willing to pay), then I guess it's a matter of prioritizing.  Worst case scenario, I can always add the UHA-6S.MKII on top of the DX90 later on. My bank account just suffered the price of the JH13s, so taking it one step at a time sounds reasonable. What do you think?

 
Yeah, in many cases (but not always, e.g. I perceive the Shanling M2 and HiFiMe 9018d as playing on the moderately brighter side despite being very hissy) the warmth is coming from audible hiss.
 
I also think that it would be the best option to give the DX90 another shot. Maybe swap devices for one or a few days.
 
Sure, you could add an amp to the DX90 anytime, but imho it isn't necessary as it is very powerful, has extremely good hiss performance and a very clean output. And don't expect the UHA-6S.MKII to add much smoothness in terms of timbre, it is (to my ears) an extremely neutral sounding device with just a smidgen of smoothness.
 
 

   
Say I do get the UHA-6S.MKII, to which one of the usage option (analog amplification or using the DAC of the amp) you were referring to for solving the hiss problem best? 
I guess this relates back to how good is the DAC of the UHA-6S.MKII compared to the DAC of the X5 or DX90...

 
All of the source devices already have excellent internal DACs, so it wouldn't be necessary to use the Leckerton's internal DAC option (but for PC/TV/Films/Gaming, it is highly recommended). Using the analogue Line Out of the DAP and the Leckerton's analogue Line In, you also get much better battery life out of the UHA-6S.MKII.

 

[zg1984]

Yes, I'll give the DX90 another try. Being relatively new to the high-end auido equipment world, I think my ears (or, precisely, my brain) still gets used to enjoying neutral sound. Need to clear my perception from all the equalized garbage I've been listening to thoughtout the years.

How about the DX80 in the context of what we're talking about... Did you get a chance to listen to it and appreciate the hiss/sound sig?

 

[HiFiChris]

I'm actually really enjoying the DX80 after some initial scepticism. Yes, it is more organic/analogue and smoother than I am used to, but over time I really learned to appreciate it an frankly even admit that I kind of love its sound. Most of the time, I am using it on the go or in the office. Hiss levels are pretty high for me with sensitive IEMs, but on the go that is tolerable and stationary I am using less sensitive stuff (some dynamic driver IEMs and full-sized headphones for example) or just adding the Leckerton to the Line Out (the organic and analogue character isn't as present as from the headphone output, but surprisingly still there - it seems like a good amount of that organic, analogue character is coming from the DAC chips' implementation).

 

[zg1984]

I see, so the DX90 is a better option for my needs. I read somewhere that the DX90 is discontinued making the DX80 its successor. Is that true? 
 
If so, it's funny how the hiss level of the successor are higher - aren't they supposed to be improving the product and not the other way around...

 

[HiFiChris]

Yes, DX50 and DX90 are discontinued; the DX80 is their successor and replaces both.
 
Operation and menu are highly improved with the DX80 and with full-sized and not very sensitive headphones, hiss is clearly below the audible threshold. Was the Mercedes W210 worse than the W124, its predecessor? Some say yes, some say no and some areas were improvements whereas in others the older W124 was better. It's a matter of preference and imho the DX80 has got the better soundstage (more depth). Hiss with sensitive IEMs is bothersome nonetheless.

 

[zg1984]

Hi Chris,
 
Now I'm really confused. I've posted a similar question on the JH13v2 thread and didn't get too much attention there (nothing close to the beautiful information and explanations you've provided me with). But now, a guy named Uncle E1 said I should "add a resistor" and referred me to this link:  

http://www.head-fi.org/t/601669/impedance-adapters-cables-explained-listed​

 .
 
The goal of this resistor approach seems to reduce the sensitivity of the IEMs to get rid of the hiss. But isn't the sensitivity of the JH13 is what makes them so great from the first place? I'd love to get your take on this - would adding a resistor is something you recommend doing? How does this compare to adding and amp or going for a hiss-free DAP?
 
Thanks again for all the help!

 

[HiFiChris]

Adding a resistor adapter (e.g. a small cable with integrated volume control wheel) would indeed reduce the IEMs' sensitivity and therefore eliminate hiss from a certain point on, but this comes at the cost of a huge disadvantage: as you may have probably noticed, all of the devices I have mentioned (including the X5k you own) have got a low output impedance (even clearly below one Ohm). Your IEMs are multi-drivers with a crossover network and therefore don't follow a flat impedance response, wherefore a source with a low output impedance is required to achieve the "true" sound. Driven by a high impedance source or adding resistance to the output (what would be the case when using such a volume attenuator cable or cable with built-in resistors), the tonality will be clearly altered, following the impedance response's characteristic (e.g. if the IEM has a lower resistance in the treble than in the mids and bass, it will definitely lose treble energy when used with a high impedance output).
Don't use a volume attenuator or resistance cable - while it reduces the sensitivity, it also skews the frequency response of IEMs with non-flat impedance response.

 

[zg1984]

Got it! Wasn't even going to entertain the though without your OK on this. So that's off the table. It sounded fishy...
 
So bottom line, what's the best way to drive the JH13s to get their 'true' sound (as you referred to it)? Is it just the DX90 or my X5 with the UHA-6S.MKII amp? I've read around that JH13s owners testify that an amp really opens these guys up. All in all I'm after the best possible sound experience. Having invested over 1.5K in my equipment, I'm ready to go a bit further to lock it down.
 
If the amp is the answer, there have several op-amp options. Which is the right one for the JH13s?

 

[HiFiChris]

Depends on your preference. I haven't heard the newer FiiO devices so can't comment on them, but my classic X3 (which is said to have the lowest amount of hiss out of the X5, X5k and X3k) sounds pretty neutral to me with just a very slight smoothness (comparable to my UHA-6S.MKII). Volume-matched (metrologically and not by ear), the tonal and technical differences between various devices are usually not night and day but rather small most of the time. Metrologically, the best possible combination would be any source, the Chord Mojo as DAC and one of the Vorzüge devices as Amp. That could give you a bit more clarity and transparency, but don't expect super much. All of that goes at the expense of (trans-) portability and you are carrying a thick stack around.
Haven't heard that combo myself but know people who did and measured both (metrologically, the values are as good as it can possibly get, but the question though is how much of that is really audible in a correctly volume-matched comparison, as our ears are no super exact lab-grade measurement gear).
 
Personally, I am nowadays rather using an all-in-one device solution than carrying a large double- or triple-stack with me (which I used to do some years back), even if I am missing the last few percents of possible measured values.
Because let's face it, real volume matched comparisons make the once hugely perceived differences in terms of sound quality appear rather small and most modern dedicated DAPs like the X5 and DX90 are already extremely capable devices. Doesn't mean though that the (objectively speaking) rather small differences aren't worth to go the more inconvenient route to achieve the most pleasant sound sig to one's subjective perception. It's a personal decision in the end.

 

[zg1984]

A triple stack is definitely too much to carry around. For me, I think it boils down to either the DX90 or a DAP (the DX90 or my current FiiO X5ii) with the UHA-6S.MKII amp. Which one of those would you go for and if it's the 2nd option, which DAP would you combine with the amp?
 
By the way, could you please also comment on which op-amp option you think is the right one for the JH13s?
 
Thanks!!