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Review and Measurements of New JDS Labs Atom Headphone Amp

trl

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No, not at all, but I'll start reading the thread again...I'm sure i missed something. It's probably another NJM2068 that is actually the gain-adjust, sorry if this was already posted somewhere.
 
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Bought Atom from hifiheadphones.co.uk, shipping was fast and unit was well packet. But I got UK power adapter with it. I need to buy UK to EU adapter and will post thoughts after some testing.
 

JohnYang1997

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No, not at all, but I'll start reading the thread again...I'm sure i missed something. It's probably another NJM2068 that is actually the gain-adjust, sorry if this was already posted somewhere.
njm2068 is a dual opamp. And atom used two of those. So half of the 2068 used as input/gain stage and the other half is the composite amplifier with 49600.
It's essentially the el amp but cost down.
How do i know? I have el amp and i used multimeter to get the circuit.
So the signal path should be:
input - half2068 - volume pot - capacitor - half2068 - 49600
 
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You got lucky then :) - I ordered from JDS a week ago and it only just left Chicago in transit to the "next destination", whatever that is . Also, I'll have to pay another £20 in VAT when it arrives :(
Yeah I am still waiting on mine, it has had the status for nearly 3 weeks now. Hopefully it arrives soon.
 
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If anyone is interested at how cool the Atom runs - my room is at 22C and the warmest area of the case is running at 32C. It is the top left area where all the capacitors are. This is exceptionally cool for an amp, but if you are stacking something smaller on top of it (like the Topping D50), you may want to leave that corner uncovered. My D50 ran around 34C when stacked on top of the Atom and 29C when on its own. Still all well within safety margins for this type of equipment.
 
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Been touting the Atom on Gearslutz website (music gear/recording). One person says the 0.6dB imbalance between L&R is too high for critical mixing etc. However, this is worse case scenario right? How is the L&R imbalance compared to other headphone amps?
 

flipflop

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Been touting the Atom on Gearslutz website (music gear/recording). One person says the 0.6dB imbalance between L&R is too high for critical mixing etc. However, this is worse case scenario right? How is the L&R imbalance compared to other headphone amps?
JDS Labs Atom Headphone Amplifier Channel Imbalance Measurement.png
 
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yeah, I'd seen that, so according to that graph at many volume knob positions the imbalance will be next to nothing. Not sure how to read the graph with regards to knob position though to avoid the 0.5dB imbalance, but it appears that from 1/2 turned up till about 3/4 one would be getting negligible imbalance?
 

flipflop

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yeah, I'd seen that, so according to that graph at many volume knob positions the imbalance will be next to nothing. Not sure how to read the graph with regards to knob position though to avoid the 0.5dB imbalance, but it appears that from 1/2 turned up till about 3/4 one would be getting negligible imbalance?
Yes, the imbalance ranges from 0 to 0.3 dB in most volume positions. It's not something that will be noticeable during normal music listening and probably not something that could be detected by most people in a DBT either.
 

GoMrPickles

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yeah, I'd seen that, so according to that graph at many volume knob positions the imbalance will be next to nothing. Not sure how to read the graph with regards to knob position though to avoid the 0.5dB imbalance, but it appears that from 1/2 turned up till about 3/4 one would be getting negligible imbalance?
On mine, at the lowest volume I can hear, just for testing purposes, volume knob just above "off", the Atom's left channel is silent and there's sound from the right channel. At any volume I'd actually listen to, I can't perceive any imbalance. I do not hear this with the THX 789 AAA: I perceive the sound as equal in both channels until I can't hear anything. Simple sighted tests with music, not generated tones.

0.6dB imbalance between L&R is too high for critical mixing
I would argue that a $100 headphone amp is not designed for critical mixing. Or, I would wonder why one is mixing at barely audible levels.
 
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You got lucky then :) - I ordered from JDS a week ago and it only just left Chicago in transit to the "next destination", whatever that is . Also, I'll have to pay another £20 in VAT when it arrives :(
Yeah, I was so close to order from USA and pay VAT and duty costs, but they got it on time. You can always message JDS Labs and ask them to check your package status for you. I got a feeling that they are a very nice people willing to help.
 

amirm

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yeah, I'd seen that, so according to that graph at many volume knob positions the imbalance will be next to nothing. Not sure how to read the graph with regards to knob position though to avoid the 0.5dB imbalance, but it appears that from 1/2 turned up till about 3/4 one would be getting negligible imbalance?
The red line shows the output level which is near 500 millivolts. Worst case situation is around just 20 millivolts. The unit essentially mutes around 5 millivolts so you are pretty close to minimum setting on the volume control when that happens.
 

amirm

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Been touting the Atom on Gearslutz website (music gear/recording). One person says the 0.6dB imbalance between L&R is too high for critical mixing etc. However, this is worse case scenario right? How is the L&R imbalance compared to other headphone amps?
Some get it perfect but most of them have some deviation. One could get around it by setting the volume at max and changing the level upstream.
 
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yeah, I'd seen that, so according to that graph at many volume knob positions the imbalance will be next to nothing. Not sure how to read the graph with regards to knob position though to avoid the 0.5dB imbalance, but it appears that from 1/2 turned up till about 3/4 one would be getting negligible imbalance?
If u wanna try what chan imbalance really feels like , try some schiit gear ... than ull say the Atom is flawless
 
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