Th3Drizzl3
500+ Head-Fier
with no source. so powered on and headphones in but no rca or usb etc no music coming into it at all. and those cables disconnected.
Emotiva A-100
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KeithEmo
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We need to make a distinction here about what we mean when we say "no source".
Do you mean "the disc is playing but we're between tracks" or do you mean "the disc is stopped" or "the disc player is turned off" or "the cables are actually unplugged from the input connectors on the A-100"?
The circuitry inside the BasX A-100 is connected together pretty much the same way that analog integrated amplifiers usually are (digital processors usually use a different topology):
In the A-100, the actual amplifier section has a fixed gain.
This means that the signal being fed to the amp is always boosted by the same amount, and the noise floor on the amp itself pretty much doesn't change.
The Volume control reduces the level of the input signal - using a passive voltage divider (a potentiometer).
Being passive, the potentiometer adds no noise to the signal.
Therefore, assuming there is nothing physically connected to the input, we would expect the noise floor at the output to be the actual noise floor of the amplifier circuitry itself.
And, in principle, that noise floor would be exactly the same no matter where we set the Volume control.
There's nothing coming into the input, so it doesn't matter how much we divide down that nothing; the Volume control itself adds no noise; so all we're hearing is the inherent noise as the amplifier "amplifiers nothing".
In practice, this isn't exactly true, because, like most amplifiers, the A-100 is a tiny bit quieter when the input is actually shorted, as opposed to almost shorted, but the difference is only a few dB.
Likewise, at least in theory, if we connect a CD player to the input, but it is actually powered off, we would expect it to be "providing a zero input", and we would expect the same situation.
Again, in practice, the extra wire hanging on the input could pick up a little noise like an antenna, and the output of the CD player might not be a very good shot.
However, for the most part, we would still expect to be hearing pretty much only the noise floor of the A-100, which should be very low, and shouldn't change when we change the Volume setting.
(And, if there is some noise, and it DOES change significantly when we change the Volume setting, then we can assume it's coming in from the wire - perhaps due to a ground loop.)
Now, lets turn the power on to our CD player (or other source).
At this point, our source is now active, so we would expect to be hearing the noise floor of its output circuitry, being amplified by the A-100.
Some devices have a lower noise floor than others, and some actually ground the output when there's no music playing, but others do not.
If you notice more noise when the source component is turned on, and that noise level changes when you change the Volume on the A-100, then you're hearing the noise floor of your source component.
The same holds true if what we've got connected to the A-100 is a preamp, or the output of a smart phone, or the output of a DAC.
If the noise floor jumps up when you turn it on, and varies when you change the Volume setting on the A-100, then you're hearing the noise floor of your source.
Now let's actually press PLAY - or start playing our digital file - or whatever.
If the noise increases at this point, it could actually be due to one or both of two different things.
We could be hearing the background noise on our actual source file, or CD, or other input source.
This noise is going to go up and down when we turn the Volume control on the A-100 up and down.
It could also vary for all sorts of other reasons.... depending on the content itself....
- the noise could drop between tracks - or not
- it could even rise and fall during an individual track (as an artifact of how the track is mixed)
The other thing is that many devices, especially some digital devices like CD players and DACs, actually "sense silence"....
When the music stops, perhaps between tracks, they actually mute their output.
Therefore, a split second after the music stops, they basically switch off their outputs - and get real quiet.
(Because of this feature, you may notice that the silence between tracks is quieter on some players than on others.)
And, finally, it's worth remembering that the noise floor is additive....
What you hear is the sum total of all the noise floors of all the devices the signal is passing through.
Although you often only notice the noise floor of whichever component happens to be the noisiest - that may change depending on what's going on at the time.
(However, if you want to confirm what part of it is the noise floor on the A-100 itself, the only real way to do that is to disconnect the input cables from the A-100 itself.)
Do you mean "the disc is playing but we're between tracks" or do you mean "the disc is stopped" or "the disc player is turned off" or "the cables are actually unplugged from the input connectors on the A-100"?
The circuitry inside the BasX A-100 is connected together pretty much the same way that analog integrated amplifiers usually are (digital processors usually use a different topology):
In the A-100, the actual amplifier section has a fixed gain.
This means that the signal being fed to the amp is always boosted by the same amount, and the noise floor on the amp itself pretty much doesn't change.
The Volume control reduces the level of the input signal - using a passive voltage divider (a potentiometer).
Being passive, the potentiometer adds no noise to the signal.
Therefore, assuming there is nothing physically connected to the input, we would expect the noise floor at the output to be the actual noise floor of the amplifier circuitry itself.
And, in principle, that noise floor would be exactly the same no matter where we set the Volume control.
There's nothing coming into the input, so it doesn't matter how much we divide down that nothing; the Volume control itself adds no noise; so all we're hearing is the inherent noise as the amplifier "amplifiers nothing".
In practice, this isn't exactly true, because, like most amplifiers, the A-100 is a tiny bit quieter when the input is actually shorted, as opposed to almost shorted, but the difference is only a few dB.
Likewise, at least in theory, if we connect a CD player to the input, but it is actually powered off, we would expect it to be "providing a zero input", and we would expect the same situation.
Again, in practice, the extra wire hanging on the input could pick up a little noise like an antenna, and the output of the CD player might not be a very good shot.
However, for the most part, we would still expect to be hearing pretty much only the noise floor of the A-100, which should be very low, and shouldn't change when we change the Volume setting.
(And, if there is some noise, and it DOES change significantly when we change the Volume setting, then we can assume it's coming in from the wire - perhaps due to a ground loop.)
Now, lets turn the power on to our CD player (or other source).
At this point, our source is now active, so we would expect to be hearing the noise floor of its output circuitry, being amplified by the A-100.
Some devices have a lower noise floor than others, and some actually ground the output when there's no music playing, but others do not.
If you notice more noise when the source component is turned on, and that noise level changes when you change the Volume on the A-100, then you're hearing the noise floor of your source component.
The same holds true if what we've got connected to the A-100 is a preamp, or the output of a smart phone, or the output of a DAC.
If the noise floor jumps up when you turn it on, and varies when you change the Volume setting on the A-100, then you're hearing the noise floor of your source.
Now let's actually press PLAY - or start playing our digital file - or whatever.
If the noise increases at this point, it could actually be due to one or both of two different things.
We could be hearing the background noise on our actual source file, or CD, or other input source.
This noise is going to go up and down when we turn the Volume control on the A-100 up and down.
It could also vary for all sorts of other reasons.... depending on the content itself....
- the noise could drop between tracks - or not
- it could even rise and fall during an individual track (as an artifact of how the track is mixed)
The other thing is that many devices, especially some digital devices like CD players and DACs, actually "sense silence"....
When the music stops, perhaps between tracks, they actually mute their output.
Therefore, a split second after the music stops, they basically switch off their outputs - and get real quiet.
(Because of this feature, you may notice that the silence between tracks is quieter on some players than on others.)
And, finally, it's worth remembering that the noise floor is additive....
What you hear is the sum total of all the noise floors of all the devices the signal is passing through.
Although you often only notice the noise floor of whichever component happens to be the noisiest - that may change depending on what's going on at the time.
(However, if you want to confirm what part of it is the noise floor on the A-100 itself, the only real way to do that is to disconnect the input cables from the A-100 itself.)
KeithEmo
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In that case, you should be hearing just the noise floor on the A-100... and it should change very little with the position of the Volume control.
KeithEmo
Member of the Trade: Emotiva
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It's also worth remembering that our ears have a sort of built-in automatic gain control... and it is actually remarkably effective.
When things get quiet, the sensitivity of our hearing gets boosted by a significant degree, and continues to boost even more with time.
There is an actual mechanism that adjusts the sensitivity of our ears themselves based on the average sound level.
This is why things sound real quiet for a few minutes after you turn off the lawn mower.
However, there is another mechanism that occurs in our brain itself, which causes us to stop noticing steady continuous noises - like amplifier hiss and your air conditioner.
These two mechanisms operate together - and sometimes produce interesting results.
You finish mowing the lawn and everything seems quiet for several minutes...
Then things return to normal...
Then the air conditioner turns on, and you notice the sound it makes for several minutes...
But, after a while, you stop noticing it - because you "become used to it".
(And also because, since the noise level has now bumped up a bit, the sensitivity of your ears drop somewhat again.)
In the case of listening to music, you tend not to notice the noise floor while the music is playing, because the music is much louder.
Then, after the music stops, and the sensitivity of your ears cranks up, you start noticing the noise floor.
Then, often, some minutes later, you again stop noticing the noise floor "because you get used to it".
It can be interesting to get yourself a sensitive SPL meter and see how the actual sound level correlates to what you THINK you hear
When things get quiet, the sensitivity of our hearing gets boosted by a significant degree, and continues to boost even more with time.
There is an actual mechanism that adjusts the sensitivity of our ears themselves based on the average sound level.
This is why things sound real quiet for a few minutes after you turn off the lawn mower.
However, there is another mechanism that occurs in our brain itself, which causes us to stop noticing steady continuous noises - like amplifier hiss and your air conditioner.
These two mechanisms operate together - and sometimes produce interesting results.
You finish mowing the lawn and everything seems quiet for several minutes...
Then things return to normal...
Then the air conditioner turns on, and you notice the sound it makes for several minutes...
But, after a while, you stop noticing it - because you "become used to it".
(And also because, since the noise level has now bumped up a bit, the sensitivity of your ears drop somewhat again.)
In the case of listening to music, you tend not to notice the noise floor while the music is playing, because the music is much louder.
Then, after the music stops, and the sensitivity of your ears cranks up, you start noticing the noise floor.
Then, often, some minutes later, you again stop noticing the noise floor "because you get used to it".
It can be interesting to get yourself a sensitive SPL meter and see how the actual sound level correlates to what you THINK you hear
Th3Drizzl3
500+ Head-Fier
keithemo please note i love mine and im totally happy with it. ive known the noise was normal sine i got it. just want to make sure you know i was simply trying to explain that to the other couple people saying they had noise.
KeithEmo
Member of the Trade: Emotiva
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Absolutely - and I'm glad you're enjoying it.... which is, after all, what really counts here.
I just have a feeling that a lot of people have very different expectations... and even a few different ideas about what noise floor is - and where it comes from.
The A-100 is not, and never will be, the quietest headphone amp on the planet.... that's not it's strength.... but we've had very few actual defective ones come back.
I just have a feeling that a lot of people have very different expectations... and even a few different ideas about what noise floor is - and where it comes from.
The A-100 is not, and never will be, the quietest headphone amp on the planet.... that's not it's strength.... but we've had very few actual defective ones come back.
garbulky
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I say for the right headphones, this is really a very good amplifier. It's the sense of ease with dynamics that it shines. I hope your upcoming class A balanced amp will sound as good.Absolutely - and I'm glad you're enjoying it.... which is, after all, what really counts here.
I just have a feeling that a lot of people have very different expectations... and even a few different ideas about what noise floor is - and where it comes from.
The A-100 is not, and never will be, the quietest headphone amp on the planet.... that's not it's strength.... but we've had very few actual defective ones come back.
I have one paired with Hifiman he-400i modded with flat cottonpads(I think the pads are made for ecigg) between the driver and ear. I also have angled hm5 pleater pads on them.
Sounds amazing in full power mode, with lots of room to adjust the volume.
I can barely hear the noise floor and it does not get any louder if I turn upp the the volume.
I am using aune x1s as dac.
I am truly in Love with this amp, thank you Emotiva!
Sounds amazing in full power mode, with lots of room to adjust the volume.
I can barely hear the noise floor and it does not get any louder if I turn upp the the volume.
I am using aune x1s as dac.
I am truly in Love with this amp, thank you Emotiva!
Heavyboxer
100+ Head-Fier
I am interested in purchasing a unit for not just my headphones (6xx, 4xx and lcd-2) but also for a pair of bookshelf speakers, either the Elac debut 6.2 or dynaudio m20.
Questions:
1. Would this amp be a good match for either/or speakers?
2. Can I have the headphone plugged in while I play tunes on the speakers? I know this isn't normal, but i foresee myself forgetting to unplug often.
3. Which side can I have it stand on for minimal heat issues, since I have limited desk space and initially planned to place the R2R-11 on top (with little spacers so the vents are still functional)?
4. Can I order the amp with the jumpers in place and have noise floor checked and passed as acceptable Emotiva QC levels before it gets shipped to me 10,000 miles away? If additional costs are involved, I would be happy to pay.
Hope someone from Emotiva can answer some, if not all my queries.
Questions:
1. Would this amp be a good match for either/or speakers?
2. Can I have the headphone plugged in while I play tunes on the speakers? I know this isn't normal, but i foresee myself forgetting to unplug often.
3. Which side can I have it stand on for minimal heat issues, since I have limited desk space and initially planned to place the R2R-11 on top (with little spacers so the vents are still functional)?
4. Can I order the amp with the jumpers in place and have noise floor checked and passed as acceptable Emotiva QC levels before it gets shipped to me 10,000 miles away? If additional costs are involved, I would be happy to pay.
Hope someone from Emotiva can answer some, if not all my queries.
Povell42
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So Amazon says they are not available due to a problem with their stock. Anyone have any idea what is going on, or when they will be available to buy again?
Oh, and has anyone use the BasX with an Audeze LCD3?
Oh, and has anyone use the BasX with an Audeze LCD3?
Last edited:
vormhat
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Wow, I think I need this amp. This would be my second Emo product. My first Emo product was basically the first amp you guys ever sold back at av123.com, the almighty LPA-1 which I still use to this day!
garbulky
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I am interested in purchasing a unit for not just my headphones (6xx, 4xx and lcd-2) but also for a pair of bookshelf speakers, either the Elac debut 6.2 or dynaudio m20.
Questions:
1. Would this amp be a good match for either/or speakers?
2. Can I have the headphone plugged in while I play tunes on the speakers? I know this isn't normal, but i foresee myself forgetting to unplug often.
3. Which side can I have it stand on for minimal heat issues, since I have limited desk space and initially planned to place the R2R-11 on top (with little spacers so the vents are still functional)?
4. Can I order the amp with the jumpers in place and have noise floor checked and passed as acceptable Emotiva QC levels before it gets shipped to me 10,000 miles away? If additional costs are involved, I would be happy to pay.
Hope someone from Emotiva can answer some, if not all my queries.
1. WIthin its 50 watts of output, yes it does fine with speakers. I've drive Axiom m80 tower speakers with them and they didn't lack composure.. However note that 50 watts is 50 watts so I don't know how hard you plan to push them. But for me, since I live in a small room, I thought its power output was adequate. Most of the time one is listening at about 1 to 2 watts of power.
2. I don't know. I don't think so. The good news is that it's okay if you forget, as you'll remember because the sound is off
3. The best way is to stand it like it is pictured. There are vents on the side and top. However the amp produces very little heat. You have to leave at least a small gap though for air flow on the three sides.
4. I doubt it. I mean, maybe, you are going to want to call Emotiva and find out. But it's not super hard to do. All you need is a screwdriver.
MyPants
100+ Head-Fier
Yeah for what it's worth, it took me like ten minutes to put the jumpers in, and most of that was removing and then reinstalling the case screws.
Povell42
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Just got my Emotiva Basx A-100. So far so good. If I don't have it plugged into a power cleaner it has some humming noise even on zero volume.
Heavyboxer
100+ Head-Fier
Just got my Emotiva Basx A-100. So far so good. If I don't have it plugged into a power cleaner it has some humming noise even on zero volume.
Nice!
Power cleaner = power conditioner?
Please post a photo as I'd like to be prepared for any unwanted noise.
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