Q: High gain? Low gain? Quality difference?
Sep 25, 2016 at 10:09 PM Post #31 of 51
  Resurrecting this thread, because it has to.
 
Did an extensive test today on Gustard H10+V5i upgrade, LCD-2.1, Silver Dragon 3 cable.
Subject of comparison: gain setting -6 vs gain setting +12, volume matched "by ear".
 
After half a day back-and-forth with ~10 songs and test patterns, I finally settled on sub-bass test tones.
 
Result: on gain +12 bass extension is definitely better than on gain -6. The lower the frequency, the easier to hear the difference. On 40 hz I needed to repeat listening ~10 times t be sure I hear the diff. on 30 hz - 3-4 times. On 20 hz - it was obvious from first listen.
 
In all cases  I was using rather low volume. On 40 hz test it would be at ~15% with high gain, ~30% at low gain.
 
Conclusion: high gain could help even if you are far from maximum volume. It seems to increase total power which is most obvious in bass. But I also agree, on some amps, especially portables, high gain dramatically increases noise. So there's a trade-off involved.


Repeated this experiment today with matched volume. -6db @ 100% == +12db @ 30% in Windows.
 
This time it was much harder to figure out the diff. Yet something was there. At first I was not sure whether it's volume difference or depth difference. But on high gain, 20hz were putting more pressure on my ears than low gain same volume. I was able to confirm yesterday's observations only after listening to 25hz first, then 20hz. Took me 2 hours. Oh, I'm likely crazy.
 
This also confirms that differences are very subtle, that's why cable makes a bigger diff in my system.
 
Sep 29, 2016 at 11:23 AM Post #32 of 51
In my experience with the LCD-2 and some Schiit amps, the high gain mode always sounds better. At low gain, the sound becomes too soft, has less attacks, impacts. Generally it is a vague and too laidback sound. I dont know the reason.
I have not tried using amp with iems but i will in near future ^^
 
Sep 29, 2016 at 2:33 PM Post #33 of 51
The best gain is NO gain.

Old school thinking, with old school amps was that volume setting should be in the middle of the knobs range.

Also, many people thought that using too high a volume was bad.

However, the truth is, the volume control is actually an attenuator. That means that at the low end of the range, the incoming signal is being restricted heavily. Ie. It is being throttled.

Conversely, at the maximum volume range, the incoming signal is free to pass through the amplifier.

Gain is a stage that causes the incoming signal level to be multiplied (amplified). With that comes noise & distortion.

So, for technically better sound, no gain is better.

Gain only becomes necessary if the volume at maximum is not loud enough!

If you're hearing an improvement at higher gain, it's likely that the SPL is slightly higher, or that you're hearing a distortion that you like!
Proper comparative testing requires measuring the amp output level to match volume setting at different gain levels. The next best is using a sound level meter with white or pink noise.

- Elmura Audio

Android powered
 
Sep 30, 2016 at 10:30 PM Post #34 of 51
Gain only becomes necessary if the volume at maximum is not loud enough!

If you're hearing an improvement at higher gain, it's likely that the SPL is slightly higher, or that you're hearing a distortion that you like!
Proper comparative testing requires measuring the amp output level to match volume setting at different gain levels. The next best is using a sound level meter with white or pink noise.

- Elmura Audio

Android powered

Yeah, I know all the theory. Yet pretty much I hear an improvement at higher gain. Very subtle, yet audible. Looks like at least 2 other people do as well. I matched the volume using a sound meter + pink noise. When switching gain from low to high I would reduce the digital volume accordingly. My output is set to 24 bit, so this should not cause loss of resolution.
 
Oct 1, 2016 at 5:28 AM Post #35 of 51
Hmm.  I notice higher sound quality with my Bryston BHA-1 on the low gain setting with both Sony Z7 and Sennheiser HD800S.
 
Oct 1, 2016 at 6:27 AM Post #36 of 51
In my experience with the LCD-2 and some Schiit amps, the high gain mode always sounds better. At low gain, the sound becomes too soft, has less attacks, impacts. Generally it is a vague and too laidback sound. I dont know the reason.
I have not tried using amp with iems but i will in near future ^^


I'm not very knowledgeable when it comes to amps and for that matter much of anything else headphone related. I did notice with my current Schiit amp and AKG K702 that same experience with high gain sounding better. When I would switch to low gain, music just sounded dull to me. Have not tried my IEMs either. Will be something I will try later after this weekend. Will also try it again with my K7XX headphones, and my K553s when I get them.
 
Oct 4, 2016 at 9:09 PM Post #37 of 51
Does switching to high gain increase output impedence? I find bass to have more rumble and overall the music to have greater attack with it enabled on TEAC HA-P50. (It's different from simply turning the volume up).
 
Dec 29, 2016 at 9:52 PM Post #38 of 51
I'm testing the high gain vs. low gain theory for myself with a Cayin C5 headphone amp, a re-cabled set of GR07BE IEM's, out of an iPhone SE set at 80% vol, playing Spotify at HQ.
On Allan Holdsworth's "Clown", from SAND, all the low end stuff, like the intro keyboard swells, the toms in the drum into, and then the bass guitar seem to have more "weight" on high gain.
Low gain sounds clear, accurate, and open, with good low end, but high gain at the same volume just has a touch more beef to me.
I'm then wondering how adjusting the iPhone volume would affect it.
So at 50% iPhone volume on high gain, the beef is still there, but the openness of the low gain I heard is there.
Seems like it's high gain with 50% source volume that sounds best.
Less distortion maybe?
Great thread guys!
I'm ordering a set of custom JH 16v2 pros and a HA-2 SE next week, so the experimentation will continue...
 
Dec 30, 2016 at 4:25 AM Post #39 of 51
Captain here and here are the facts:

- Higher gain means more amplification, including noise.
- Volume pots aren't perfect and track better at the middle.
- Digital volume control doesn't degrade quality, usually.
- Subjective impressions are worthless.
- Louder volume sounds "better" than lower volume. It's demonstrated in experiments. This is why higher gain vs lower gain listening tests may become unreliable as the person must adjust volume. Without a way to measure volume, this is unreliable.

In a properly designed amp, gain adjustment will have higher noise at higher gain. The "sound quality" will not change because it cannot change unless there are issues in the circuit.

Most amps will never include gain adjustment as this requires changing the resistor values in the circuit. They might just add inline resistors to drop the input signal a bit (exactly what a pot dies).
 
Dec 31, 2016 at 2:15 PM Post #40 of 51
Just love this thread! A lot to learn here on a subtly confusing/non-intuitive topic.
 
One of these days I'll test the effect of higher gain on sound quality for myself. It will be less than perfectly scientific, since I'll only be able to match volume by ear.
 
Still, I'm interested enough to want to experiment w/it...
 
Mar 16, 2017 at 9:06 PM Post #41 of 51
With something like the O2 amp if you put headphones in (and no signal) and crank it it to max on low gain, you will hear noise. It was explained to me by JDS, that yes the 02 is "silent" but only up to something like 100dB or 105dB, which realistically is pretty much max safe listening levels and If you are listening to Skrillex at 105dB, you are not going to be bothered by a tiny bit of noise.

105dB safe listening volume? LMAO. With Skrillex at 105dB you're getting tinnitus in a jiffy.
 
Mar 16, 2017 at 10:26 PM Post #42 of 51
105dB safe listening volume? LMAO. With Skrillex at 105dB you're getting tinnitus in a jiffy.

 
I already have tinnitus--lots of it. I'm one of the lucky ones whose tinnitus is white noise-like rather than note-based. Still, it's a big factor in my headphone listening, which I've learned I can't do as often or at as high a volume as I'd prefer (if I push it, tinnitus flares, headaches come, and it becomes very clear "it's time to stop").
 
So consider my biases when I say some on head-fi seem to listen at levels that (to me, at least) are shockingly high. I've seen threads elsewhere on Head-Fi when people who own the same amps & headphones talk about what gain settings they use--usually in light of the output voltage of their source DACs. Sometimes when posters compare notes in this way, they discover that they listen the headphones for extended periods are volumes far higher than others are doing. Those threads are interesting and a little horrifying to me...
 
This is not a "moral" issue. There's no right or wrong--just a continuum stretching from moderate volume music enjoyment all the way to headbanging volume & destruction of hearing. What's surprising to me is that people actively enjoy headphone listening at volumes that will pretty almost certainly cause hearing loss, now or later.
 
It makes me recall a number of very loud music concerts in my youth. In those days I actively enjoyed volumes that today would cause instant migraine. I didn't wake up to the danger of loudness until I hit my 40's. Oddly enough, it wasn't music that made me realize this--it was power equipment. I began routinely cutting the grass w/lawn tractors that made high decibel noise; also started using loud snowblowers; and doing frequent woodworking w/table saws, routers, planar, etc (planar & router in particular are extremely loud up close). Everyone recommended ear protection for these activities, so I dutifully began using sturdy/effective ear protection & have ever since.
 
Only later, when tinnitus showed up, did I realize the damage had already been years before. I now use ear plugs to listen to loud live music, have for ~10 yrs.
 
But here's a key difference between my volume issues & what I read about on Head-Fi: I never heard a pair of headphones in any serious way until ~2 yrs ago. My exposure to high volumes was almost entirely related to live music. But with headphones, one can easily dial it up to maximum volume, as often and for as long as desired. That's really playing russian roulette w/one's hearing.
 
Apr 12, 2017 at 12:33 PM Post #43 of 51
Thanks I actually used this as sort of a reference as to rather or not I should use a pair of low ohm headphones in my fiio e09k.
 
I wont, even on low gain setting I think I just might turn it on and hear a poof then nothing at all so better to be safe than sorry.
 
Apr 13, 2017 at 6:25 PM Post #44 of 51
  Does switching to high gain increase output impedence? I find bass to have more rumble and overall the music to have greater attack with it enabled on TEAC HA-P50. (It's different from simply turning the volume up).

 
Just re-reading some posts and stumbled over this one. When I first read it, I didn't understand its implications.
 
Right now on the ZMF Eikon & Atticus thread, several Head-Fi'ers have embarked on experiments regarding increasing/decreasing the output impedance of a given SS amp (using adapters w/high quality, appropriate-value resisters inside)--to see what effect this will have on the Atticus headphone in particular. This issue came up because a number of posts by different members suggested that:
  1. Compared to the Eikon, the Atticus seems unusually "picky" about the amps that drive it.
  2. A number of people get great results with tube HP amps, claiming that the midrange of this headphone "opens up." Note that tube amps on average have higher output impedance (ie, seen at the headphone load) than do SS amps.
    1. BUT...balanced outputs, which are said to sound wonderful with all the ZMF headphones, are only really available on SS amps.
  3. Paradoxically, even on super-powerful SS amps, some people observed that the Atticus did not open up as expected with all that power (amps like the Milo, Violectric V281, etc). So it's apparently not a power (voltage & current) issue. In other words, pure gain, up or down, seems to not matter as much as somewhat higher impedance.
  4. There is a SS amp with variable output settings (Garage1217 "Project Polaris: http://www.garage1217.com/garage1217_diy_tube_headphone_amplifiers_015.htm), and a couple of comments about this amp suggested selecting the 2nd or 3rd highest of the output impedance settings had a effect on HP sound (things like slight loss of bass impact traded for greater soundstage and midrange presence)
 
Those of us who obsess over the Atticus are watching that thread with great interest. I am extremely interested in the Atticus and own 2 uber-powerful SS amps (V281/balanced & Audio GD SA-31SE), as well as 1 moderate power one (Liquid Carbon/balanced)--so I'd love to know that I can use these amps w/an Atticus & vary output impedance via adapters to get better (or at least different) sound.
 
All to say this post by @stalepie is quite prescient/insightful, as it turns out...
 
Apr 13, 2017 at 6:48 PM Post #45 of 51
This is an interesting topic that I have just started to delve into. I noticed that, after volume matching, that I think the higher gain setting on my Schiit Audio Mjolnir 2 sounds better to me than the lower gain setting. I found out that Schiit is using more negative feedback in the Mjolnir 2 to get the lower gain. Once I found that out, what I was hearing made sense. After all, how can more negative feedback made the sound better? It might make the specs like THD look better. But I don't see how it could make the music better.  
 

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