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Q: High gain? Low gain? Quality difference? - Page 2

post #16 of 42
Quote:
Originally Posted by Rylo View Post


There's a difference between responding to a question with a question (which wasn't informative at all), and then what you just did, which is to explain why. As a complete noob myself, the rest of the thread explained a lot.

 

Quote:
"Hmm... same circuit, a pair of resistors swapped out for another set of different value... question is about "sound quality"? confused.gif"

 

Sorry, but I know this individual well and he is as knowledgeable as anyone around here..  He was trying to be instructive.  Changing the gain with a set of different value resistors - by definition, has nothing to do with the "quality" of the sound.  Perhaps he should've elaborated, but as I said earlier, the point was well made, IMHO.

 

Want to change the "sound quality" of an amp?  Then suggest changing the sound-affecting components - capacitors in the signal path, opamps, buffers, transistors (in zero-feedback topologies), etc.  However, changing gain does nothing but change the relative position of the volume knob in relation to the output volume.

 

Yes, there are instances where the gain may be jacked up enough that it's easy to tell that there's some residual noise or hiss in the output.  However, that is never going to change the sound signature of the amp.

 

Maybe that explanation helps?

post #17 of 42

Different resistors -> changing feedback loop -> different gain -> different performance (though not by a human-significant amount, especially if not looking at a CMoy or something where you'd be adjusting the gain of the output stage), not just amplifying signal and noise by a different amount.

 

Sometimes perceived sound quality differences are attributed to more trivial things than this though.

 

Though really, I wouldn't really expect anything much other than the difference in volume (or noise if you're adjusting volume to compensate).

 

 

Anyway, as for things that practically matter, as explained earlier, use a lower gain if volume is loud enough. Avoiding a hypersensitive and possibly channel imbalanced range of a volume control is a good idea. If you never listen that quietly with whatever source output level and headphones you're using, yet you don't hear any noise from the amp, then it's probably all moot.

post #18 of 42

sorry for resurrecting a very old thread.

 

Traditionally I was always wary of using high gain. First reason was raising the noise floor, but I remember reading (of course I can't find it now) that different gain setting change the inductance (?) of the output. One of my amps is the Marantz HD-dac1 and I think it was in that amp's forum that people where explaining this. It has 3 gain settings. And while something like the HD650 will work on any of the 3 gain settings it matches for example the middle gain setting better. I have no idea if this is true or the science backs this up. When people start talking about the math behind driver/amp impedance, phase, voltage needed to drive the coils vs watts, my head starts to hurt. 

 

From my experience: 

 

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. ANYWAY, turn the gain up on the 02 and this noise floor raises. Not really a big deal, and probably still not noticible under actualy listening condition (i.e., music), but it was one reason I never wanted to use high gain on amps. 

 

I just got my hands on the Valhalla 2 and I was running HD650 on low gain, I was listening to 90% power/volume on a few songs. The thing was running HOT! So I was thinking maybe I should run these on high gain instead. 

 

Did a bit of testing. Crank the Valhalla 2 up to 100% volume on low gain, no noise. High gain? No noise at 100%.

 

High gain it is for me with Valhalla and HD650. 

post #19 of 42

(Running on a Fiio E10k :P)

 

High gain is mostly used for a power hungry headphone, such as the AKG Q701 for example. If your amp is not powerful enough to drive the phones on L gain, then switching to H gain will add more volume. Be warned, the sound will start to distort at higher volumes on high gain, and you can actually run the risk of damaging your headphones.

 

So you wouldn't use something like a pair of M50s or Sennheiser HD598 on high gain, cuz it doesn't need it lol, and it'll probably cause some damage. 

 

In terms of sound quality, as I said before, it'll distort at higher volumes. Try testing the sound if you want, you'll probably hear little to no difference.

post #20 of 42
A potentiometer is nothing but a variable resistor... High and low gain set the starting point for this resistance using static reisitors before the pot takes effect..

Think of a pot as a water faucet... You turn it on and you get water... The pressure is determined by how much you turn the knob.. Now think of the static resistors (high and low gain) as the valve under your sink.. If you turn that valve down.. You will limit the amount of pressure you can get from your faucet using the knob.

Now think about that and then come to your own conclusion on if this would effect sound quality, outside of the beginning noise floor :P
Edited by kejar31 - 6/24/16 at 6:21pm
post #21 of 42

This looks like an old thread--not sure anyone is still watching. However, last weekend I went through quite a lot of testing of gain vs sound, and found surprising results.

 

The reason was that I had purchased a used 2012 v.2 Matrix M Stage HPA-1 headphone amp/preamp, and was shocked at how good it sounded when I dropped it into my system (used as a preamp). I had purchased it to use in a desktop system I'm setting up for my brother, and had no intentions of using it my own desktop system--but after auditioning this thing, I realized that it would be perfect for my own system, so went out and found a really cherry 2013 HPA-1 for a routine test, expecting it to sound the same as the 1st one--but to my surprise, it was somewhat brighter (unwelcome IMO)...and seemed to require more rotation of the volume pot to get equivalent volume.

 

So I flipped the units over and compared gain settings (the HPA-1 has a 3 position gain setting for each channel: 0 dB; +10db; or 20dB). As it turns out, due to the very confusing labeling of the gain switch diagram, when I'd set the switches on the 1st unit, what I thought was 0 dB for each channel (ie, the lowest gain setting) was actually +20dB (maximum gain). By contrast, the second unit actually WAS set at the lowet gain setting.

 

So purely by accident, I discovered that the highest gain setting sounds slightly "warmer" (ie, less bright) than the lowest gain setting on the HPA-1. Bearing in mind that the HPA-1 is a relatively warm/euphonic HP amp/preamp to begin with, and that the amt of "brightness" I'm talking about is relatively small--it was still a surprising result, the reverse of what one would expect.

 

As mentioned earlier in this string, higher gain should theoretically be associated with lower noise; and to whatever extent circuit noise correlates with brightness, I would expect there to be less brightness at the lowest gain settings.

 

I'm still puzzled by this...

post #22 of 42

Weighing in from an audio engineering perspective - if you're working with an "active" system vs a "passive" one, gain will introduce more electricity into the signal, effectively "amping it up", more electricity introduced to the signal = more saturation / distortion.

 

So not only will the perceived noise floor be raised, the tonal characteristics, saturation / distortion, and harmonics will also be affected.

 

Additionally you may notice an increase in low end / mud as these frequencies require more electricity to be driven effectively - so there could be a loss of "clarity", but added warmth.


Edited by Seasho - 7/28/16 at 8:24am
post #23 of 42

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.

post #24 of 42

Wow--these are surprising & thought-provoking results, desik.

 

In my post above, I reported a very small subjective difference in "warmth" between different gain settings of the Matrix M Stage HPA-1 amp. But at no point in my comparison of various gain settings, using pretty good quality desktop speakers + subwoofer at a fairly loud volume setting, did I detect any subjective differencex in the bass at different gain settings. Not that I was looking for that, but I would have noticed, since the deepest bass can be felt as well as heard--and my 5-6 cut audition list happened to feature plenty of quality bass.

 

But with the evident quality of your equipment chain, and the fact that you heard this via headphones, which by their nature facilitate focus on details of the sound--also the fact that you apparently were looking at graphical depiction of frequencies you were hearing--well, it's kind of hard to doubt what you're reporting here.

 

Obviously this finding could be specific to the Gustard H10. Then again, I really need to compare those HPA-1 gain settings again, this time with a good pair of headphones.

post #25 of 42
Quote:
Originally Posted by desik View Post
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.

 

 

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.

 

I was wondering the same thing about myself. I kept noticing that higher gain made music seem to sound better and fuller on both my Violectric V281 and Schiit Lyr 2 for some reason. Thx!


Edited by FumblingFoo - 9/25/16 at 3:11am
post #26 of 42
Quote:
Originally Posted by FumblingFoo View Post
 

 

I was wondering the same thing about myself. I kept noticing that higher gain made music seem to sound better and fuller on both my Violectric V281 and Schiit Lyr 2 for some reason. Thx!


Yes, I actually first noticed the difference 2 weeks ago when listening to some symphonic metal. It was sounding a bit "fuller". Like gradual tonal transitions were more smeared out on low gain, but were more melodic on high gain. Then yesterday when listening to different songs I noticed that drums sound a bit sharper on high gain, and have their attack sort of blurred on low gain. But after repetitive listening I wasn't so sure anymore. Our brain tries to compensate what we hear with what we expect to hear, according to more knowledgeable folks.

 

After many more trials, bass tones provided the most unmistakable difference. How big the diff is? 20 hz on low gain sounds somehow in between 20 and 30 hz at high gain. Headphones still produce plenty of 20hz, but it is more mixed with higher harmonics I guess. Add to this lower hearing acuity at 20hz, and even a small extra distortion can make a big difference.

 

I would like to know a scientific explanation of this.

post #27 of 42
Quote:
Originally Posted by desik View Post
 


Yes, I actually first noticed the difference 2 weeks ago when listening to some symphonic metal. It was sounding a bit "fuller". Like gradual tonal transitions were more smeared out on low gain, but were more melodic on high gain. Then yesterday when listening to different songs I noticed that drums sound a bit sharper on high gain, and have their attack sort of blurred on low gain. But after repetitive listening I wasn't so sure anymore. Our brain tries to compensate what we hear with what we expect to hear, according to more knowledgeable folks.

 

After many more trials, bass tones provided the most unmistakable difference. How big the diff is? 20 hz on low gain sounds somehow in between 20 and 30 hz at high gain. Headphones still produce plenty of 20hz, but it is more mixed with higher harmonics I guess. Add to this lower hearing acuity at 20hz, and even a small extra distortion can make a big difference.

 

I would like to know a scientific explanation of this.

 

Yes, I very much concur. My research tells me that gain simply makes the sound coming out of my amp at a given volume louder, so that if max volume at lower gain isn't enough, I can simply up the gain to get more power. And, that being constrained to the lower end of the volume is supposedly the range of lower sound quality for amps. But my brain tells me that even with gobs of power available in the higher end on a lesser gain, higher gain even at the lower end of volume adjustment makes for fuller sound with better bass. Google has not been my friend.


Edited by FumblingFoo - 9/25/16 at 10:29am
post #28 of 42

Update: today I tried to compare what makes a bigger diff to SQ: custom cable or higher gain setting.

 

Cables compared: ZMF stock 5 feet vs Silver Dragon 3 15 ft.

Gains compared: -6db vs +6db vs +12/db on Gustard H10+V5i

Headphones: LCD-2.1

Music used: one symphony and one heavy metal song.

 

Long story short:

In music: SD3/+12 > SD3/+6 > SD3/-6 > ZMF/+12

In bass depth alone: ZMF/+12 > SD3/+6

 

Volume was carefully matched this time.

In 20hz bass depth test tone I feel like cable makes smaller diff than the gain setting, possibly no diff at all.

 

But in music cable makes a bigger difference than gain settings. I believe I heard the pros and cons of both. Still prefer the extra female voice sweetness of SD3 to the extra bite of high gain.

 

Next time will try to compare different amps.

post #29 of 42

I really like the direction you're going in here, desik--not to mention the time & energy you're putting into chasing down these small (but significant) differences.

 

When it comes to cable changes affecting sound, we may get stomped for saying this (it seems to be controversial on Head-Fi). I've been messing w/audio for years, at times w/pretty high-end gear. And I can report that most times I changed cables (interconnects or speaker cables), I heard at least some differences; sometimes it was subtle, and occasionally it was anything but. Often the changes were beneficial, but sometimes not.

 

I never found any correlation between cost or design/engineering claims for the cable, and how much it improved sound (that would be too easy).

 

My experience w/headphone listening is less extensive (not quite 2 years), but I've already had one positive experience. Recently wwapped the stock cable on my Fidelio X2's for an equal-length replacement made by Ghent Audio (link below)--3M, 3.5mm on one end, 6.35mm on the other, thick and sturdy/well clad, costing just 16.50 (!). I already loved the sound of these 'phones and didn't expect to hear anything by swapping cables--but I did. A little hard to put into words...the sound just opened up a bit, with a little more bass & soundstage (already strong points of these headphones), maybe a touch more clarity and a little less grain in the treble. Not earth-shaking changes, but audible.

 

http://www.ghentaudio.com/part/d08.html

 

I recommend Ghent Audio. These are well made, inexpensive cables. Xu Ghent treats customers well. Can't tell if he makes the kind of cables used in ZMF Omnis, but I'll bet they can be ordered as custom (custom audio cables are listed on the site). I hope to get a pair of ZMF Omnis in the next 6 months or so; I'll check that out.

post #30 of 42

Nice findings, desik :normal_smile :, you've inspired me to do some testing of my own, finding similar results with the Violectric V281.

 

The test track I used as "Animals" by Maroon 5, using a pair of Beyer T90's on the Violectric V850 -> V281, a warm-neutral amp with lots of power. I adjusted the volume each time to my maximum comfortable listening level, which is ranged from 85 - 92dba within the track.

 

From -12 to 0 to +12 gain, there was increasing extension of lower bass in the 20hz range, with the low level hum gaining more presence and going from the background to more in line with the foreground, but well meshed. Bass response seemed to remain about the same.

 

I'll have to do more in-depth testing to tell whether or not there are other sonic differences, but I'm a bit of a newbie so I can't guarantee that I'll be able to listen critically enough to provide results.

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