Confused about impedance and dacs/amps

Equipment / Electronics / Gear / Accessories Headphone Amps
1

Hi all, it’s me again.

I am trying to understand DACs and AMPs and output impedance and stuff but I am a bit confused.
My situation is that I currently do not own any high impedance headphones nor do I have such headphones on my wish-list, I do have the Koss Porta Pro and KSC75 and some IEMs with more on the wish-list. I own an E10K, and on my IEMs I can not turn the knob further than 1, if I use my EarBuddy I can reach 2, before risking hearing loss. On my Koss’s I can not go further than 2 without EarBuddy.
I do however hear a clear difference between the E10K and connecting my stuff directly to my PC/Laptop, so even if I don’t need an AMP I still need something, probably just the DAC part. What I’ve heard is that at very low volumes the sound is actually worse due to cut off dynamic range (not sure if this is true).

So I went looking on AudioScienceReview for AMPs and there output impedance, thinking that if I have a DAC/AMP with lower output impedance that I can actually use more of the volume control. However the E10K apparently has a very low output impedance. So now I’m wondering: what determines whether there is background noise (hisses and stuff) and what are the properties of the AMP and headphone that determine how far you can turn the volume control before going deaf.

Not necessarily looking for recommendations (though they are always welcome) but mostly more of a technical explanation so I understand and am able to get these things from reviews and specifications myself.

Thanks :slight_smile:

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2

Many things imo. Assuming you have an amp with low output impedance, the overall quality of power delivery and design of the amp can determine noise floor. The gain of the amp can determine volume control and affect noise floor as well. The way the volume pot is designed and how it’s configured will affect how much you have to turn it up to get the desired volume. Some of this stuff really isn’t listed in the specs and you would want to look at measurements to determine other aspects like the gain and noise (but imo it’s mainly listening tests that will give you the final info)

3

I can drive my FH7’s off my iPhone, the Micro on eco, normal or turbo and no hiss on any of them…how come?

4

What’s your ie match setting on?

5

:eyes:’s…Off, I’ve never used it :flushed:

6

Lol. Well TBH the ifi is a quality amp, and they designed it well so there really isn’t much in the way of extra noise in the signal. The unit also runs off of a battery which is helpful for removing mains noise or things like that

7

Cool the power modes make a massive difference in volume control obviously, the ie matches change both the volume and sound at the same power setting, if you then mess with both power and iem matches they seem to cancel each other out and sound the same to me…if that makes sense?

Edit…and no hiss on any of the above sttings

8

Ah well something like how the volume pot is designed I have never seen in a review, so that’s probably a difficult one to find out. It just bothers me a bit that I can only put it at the first level even though it’s in low gain mode, so I have barely any volume control whatsoever.

9

How is the volume vontrol with the iFi Micro? Afaik the FH7’s have the same impedance and almost the same sensitivity as my FA1s, so I guess these would be comparable.

10

Ok still listening to Styx on the Micro with the FH7’s no iem match… listening level on eco setting( the volume knob starts at 20 to…to 20 past o’clock don’t ask me lol) at 10 past is loud no hiss…Normal setting 12 o’clock loud no hiss, turbo mode 9 o’clock and (LOUD) no hiss.

11

Well I guess I better start saving up then. It’s roughly 3-4 times more expensive than I was planning to spend unfortunately.
Thanks :slight_smile:

12

I’m sure there’s lots of amp/dac’s that would be ok…just giving my feed back hope you find a cheaper cure :+1:

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13

SNR - signal to noise ratio: can also be a rough guideline for noise floor. typically higher SNR amps have lower noise floor. IEM can be tricky because they are typically more sensitive then most amps, which are designed for headphones and speakers with higher impedance and less sensitivity.

as an example: my lyr3. can’t hear a thing with any of my headphones. go low gain jack squat for volume(its a beast) and hook up iem’s, and its a buzzfest. the SNR of the lyr3 is crap, but headphones do not care because they are crap in efficiency.

Point though: all amps have noise floor, there is no clean amp. You can always design a speaker more efficient then the best amp and hear the noise it produces.

Also I am not an expert at all and I wish I could lay this out in better terms and technicalities. Amps for IEM’s usually have very high SNR’s so you do not get as much noise using IEM’s.

As far as how much power an amp has, most have a milliwatt or watt rating on them. some just have spl ratings, little harder to work with and figure out. most headphones and IEM’s have a rated power they can handle. most need very little juice to actually operate to decent volume levels.

also, like M0N mentioned, the pot can also have an effect. i have a cheap chinese amp that sounds great but has a terrible pot on it. the first 2 clicks only get you volume on 1 channel, and sounds like crap in general till about 5 clicks, then balances out and sounds great. I mention because I could never even use IEM on it as the headphone out has muscle and would be to loud by the time the channels balanced out the right way.

Also like M0N said, there really are A LOT of factors to determine on paper if an unknown amp may have noise. But honestly unless you are planing on some DIY or spending a ton of money, just do a quick search for top rated IEM amps. Pretty all of them will be quite, and like I said, unless DIY or $$$$$$$, theres no real need to even know the why’s and hows. plenty of others have figured it out for us =)

just one persons thoughts here that is by no means an expert, pretty far from it lol. Thats just my thoughts and conclusions thus far in exploring this wonderful rabbit hole of audio.

2 Likes
14

i think, and i could be wrong, but these work well with IEM’s

edit: and is 99$

edit 2: the ifi zen is 130$, not really portable, but has more beef is you decide to get headphones later and also is suppose to work well with IEM’s. I dislike the feeling of IEM’s so i personally do not use them, so i can only say things based off of what others say when it comes to IEM’s.

15

Thanks, this is very informative!
I kinda regret sending back the Zen DAC that I bought. I payed a lot for it, but at least it gave me more volume control than I have now. I felt when I bought it that it didn’t sound THAT much different and since the DAC and a balanced cable was €185 and I didn’t know how long I would be able to send packages I had better return it fast. The main thing I think is happening is that at this low volume the channels are imbalanced, because for some reason it seems like the right channel is just a bit louder than the left one I think. My other thought would be to buy the iFi IEMatch, which adds another 12 Ohm, so I could theoretically put the volume up to 3. I’ll also have a look at the DragonFly.

16

yeah, a common problem with chinese amps, the pots are garbage as a whole. you could also add in a cheap chinese pre-amp. It will give you more volume on the same device, and more control over the volume. the solid state ones are 30-40$, the tube ones are about 10$ more.

edit: What does a pre amplifier do?

A preamplifier ( preamp or " pre ") is an electronic amplifier that converts a weak electrical signal into an output signal strong enough to be noise-tolerant and strong enough for further processing, or for sending to a power amplifier and a loudspeaker. Without this, the final signal would be noisy or distorted.

from wiki on preamps.

17

So would I then connect my PC to my E10K and then the line-out of the e10k to a pre-amp and then my headphones to the pre-amp? That sounds counter intuitive since I’d logically not place a pre-amp at the end of a chain (I have to admit I don’t know what exactly a pre-amp does and how it’s different from a regular amp).

18

the pre-amp goes before the ek10. in between pc and ek10. you typically put the pre-amp after the DAC but before the AMP

19

So I’d have to get both a DAC and a pre-amp or an amp and a pre-amp.
I was looking at the Schiit Heresy earlier, I might consider that and then hook the Heresy up to the line out of the e10k, but I find conflicting opinions on the internet on whether that bypasses the amp in the e10k.

20

the pre-amp with have a volume nob on it. you could as an example, have it set to 50%, wich would limit the amount of juice going to your amp, thereby allowing you to turn the amp up past 3 to achieve a proper channel balance.