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Review and Measurements of New JDS Labs Atom Headphone Amp

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Just in case you're not aware, ProQ's Q values are not the same as those provided by oratory1990: oratory1990's must be equated to ProQ's with an annoying equation, dependant on frequency, bitrate and Q value: q*(2*π*(f/b))/sin(2*π*(f/b))*√(2).This equation is seemingly only valid for peaking filters: I've not yet discovered the equation for shelving filters
 

Theriverlethe

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Just in case you're not aware, ProQ's Q values are not the same as those provided by oratory1990: oratory1990's must be equated to ProQ's with an annoying equation, dependant on frequency, bitrate and Q value: q*(2*π*(f/b))/sin(2*π*(f/b))*√(2).This equation is seemingly only valid for peaking filters: I've not yet discovered the equation for shelving filters
That is annoying. Any idea what EQ program Oratory1990 is using?

Edit: Are you sure? The graphs look pretty similar to me, except that I reduced the low shelf a little to taste.

https://www.dropbox.com/s/rp71fprbe1lmz7u/Hifiman HE4XX.pdf?dl=0
 
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That is annoying. Any idea what EQ program Oratory1990 is using?
Last I read, he uses menuBUS and AUNBAND (I think that's what it's called) on mac. ProQ is much better tho

Edit: Are you sure? The graphs look pretty similar to me, except that I reduced the low shelf a little to taste.
Positive. I had not only a lengthy discush on the ProQ forum1, but hours spent trying to find the precise equation and make an easy-to-use version on a calculator app. The differences in Q values are fairly small below 5 kHz or so: after eight, they become rather important. Make sure the calculator is in radians, not degrees

1: https://www.fabfilter.com/forum/3564/variable-q-values
 
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solderdude

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You can use it this way provided you have selected the right gain and have a good adjustment range and can get loud enough.
When your adjustment range is too small and you only can use the bottom part of the volume control then it is no problem to lower the volume on the source. This will/should not harm the sound quality.
 
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I would also use 24 bits if you plan to use the OS volume. That allows -48dB reduction without truncating 16 bit audio.
Yeah well I'm listening to everything using Tidal HiFi and I have windows set to 16bit 44.1hz. So I should change it to 24bit 44.1hz and leave the volume at 100%? also I'm using a topping d30 for my dac and not the onboard one if that matters.
 
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Yeah well I'm listening to everything using Tidal HiFi and I have windows set to 16bit 44.1hz. So I should change it to 24bit 44.1hz and leave the volume at 100%? also I'm using a topping d30 for my dac and not the onboard one if that matters.
If you use exclusive mode in Tidal it might control the hardware volume. I'm not sure. If not using exclusive mode the audio goes through the Windows mixer and you can set any bit depth you want (but Tidal won't switch sample rate when playing master files).
 
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If you use exclusive mode in Tidal it might control the hardware volume. I'm not sure. If not using exclusive mode the audio goes through the Windows mixer and you can set any bit depth you want (but Tidal won't switch sample rate when playing master files).
Yeah when I use exclusive mode windows and tidal stay at 100% volume and it can only be controlled further from the atom. I can still change the sample rate manually but the topping d30 isn't MQA compatible so I just leave it at 16bit. Is this correct?
 
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Yeah when I use exclusive mode windows and tidal stay at 100% volume and it can only be controlled further from the atom. I can still change the sample rate manually but the topping d30 isn't MQA compatible so I just leave it at 16bit. Is this correct?
The Tidal app can decode MQA in software up to 96khz. Personally I would use exclusive mode in Tidal and leave volume at 100% (or set force volume) and control volume with the amp. If using sensitive headphones or IEMs and having channel balance problems then it is fine to turn up the amp and use the software volume to attenuate as long as it's not too extreme you probably won't notice.
 
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And be careful you don't accidentally ramp the software volume up (my mouse scroll wheel does it if focus has not switched away from the volume control in Windows)
 
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The Tidal app can decode MQA in software up to 96khz. Personally I would use exclusive mode in Tidal and leave volume at 100% (or set force volume) and control volume with the amp. If using sensitive headphones or IEMs and having channel balance problems then it is fine to turn up the amp and use the software volume to attenuate as long as it's not too extreme you probably won't notice.
And be careful you don't accidentally ramp the software volume up (my mouse scroll wheel does it if focus has not switched away from the volume control in Windows)
Ok cool this is basically what I've been doing for everything. Exclusive mode with force volume set and I just change it from the amp itself. Just wanted to make sure I was doing the right thing. Thank you.
 

bboris77

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Matching DAC imminent! This is the latest from John Seaber on their blog: "The first batch of Atom DACs will be assembled, tested, and packaged this week."

I am actually very interested to see what this DAC brings to the table compared to the Modi 3 and the Topping E30.
 

Theriverlethe

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Matching DAC imminent! This is the latest from John Seaber on their blog: "The first batch of Atom DACs will be assembled, tested, and packaged this week."

I am actually very interested to see what this DAC brings to the table compared to the Modi 3 and the Topping E30.
They already have a DAC with aluminum chassis for $100. Maybe a plastic case with USB and SPDIF for the price of an SDAC?
 

bboris77

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They already have a DAC with aluminum chassis for $100. Maybe a plastic case with USB and SPDIF for the price of an SDAC?
It has to bring something new to the table in comparison to the OL DAC which is a fairly old design. I am assuming they will be phasing that one out. Say it is $99 and plastic - it will instantly be compared to the Modi 3 which has a metal case. I really hope it is not a simple cookie cardboard design that will just match the performance of the Modi 3.
 

Objectivist01

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I had in mind Oratory1990 thread on reddit, as its his main page. AutoEq implements it a bit differently. Oratory1990 only provides pdf with measurement and how to set it up correctly.

https://www.reddit.com/r/oratory1990/
One question: Do you guys measure the headphones response once again after the eq is applied to see if the eq itself isn’t causing any distortion due to the limitations of the headphones driver or can design?

Some headphone companies pursposefully leave the headphones with a non ideal response because since that response would be a balance between distortions due to the limitations kicking into to audible area.
 

magicscreen

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It has to bring something new to the table in comparison to the OL DAC which is a fairly old design. I am assuming they will be phasing that one out. Say it is $99 and plastic - it will instantly be compared to the Modi 3 which has a metal case. I really hope it is not a simple cookie cardboard design that will just match the performance of the Modi 3.
I do not understand this matching performance.
In this site there is no audible difference between well engineered DACs.
So I should buy this Atom DAC for the ugly plastic case only? No way man.
 

bboris77

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I do not understand this matching performance.
In this site there is no audible difference between well engineered DACs.
So I should buy this Atom DAC for the ugly plastic case only? No way man.
That is my point exactly - unless they somehow exceed the performance/functionality of their competitors at this price point, they won’t be able to make much of an impact with this product.

One way of stirring things up would be to shift the entire Atom lineup to a basic metal case. But what would be the point of the EL DAC and the EL AMP then?
 
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