Good when genuine. V shaped sound with accurate midrange.@half_dog what do you think about AKG E0-IG955? Good, decent, sub-par etc?
Good when genuine. V shaped sound with accurate midrange.@half_dog what do you think about AKG E0-IG955? Good, decent, sub-par etc?
All the mains related noise are either from your source or are picked up by the RCA cable or other components in your measurement setup. The mains noise measured using APx555B is typically at 60nV, max under 100nV. This is so far the best ever PS noise performance from any single ended devices that I know(except for battery powered)The Amp has a relative higher PS noise compared to its noise floor.
Here's the 50mv test (more real world than full volume test, as people may normally use that volume as full volume).
the final thd+n does reach the -94db in amirm's test. So I'm measuring it correctly as he did.
On the left hand side you'll see two spikes around 50hz (PS frequency at my country), which is just -104db lower than main tone.
The noise could be audible when listening quiet passages of your music with high dynamics (such as classical) with a regular listening volume (50mv as full amplitude ).
View attachment 81017
Pretty sure the PS main noise come from the Amp, rather than DAC (a topping E30), as turning either digital volume of the DAC or analog volume of the amp does not change the noise amplitude.
The accumulated noise is 0.2-0.3uV. The PS noise is 60nV. So no, power supply noise is not the main contribution of the noise. It's the resistor thermal noise and the inherent noise of the opa1612 that is the main contribution.> All the mains related noise are either from your source or are picked up by the RCA cable or other components in your measurement setup.
All other things are battery powered. Cables are already short enough --- I specifically used 10cm cables.
> Confirmed by Wolf's measurements.https://www.audiosciencereview.com/...asurement-of-topping-l30-headphone-amp.14252/
Wolf's measurements confirmed most of the -104db noise come from the PS tone rather than random one.
His 4V FFT shows 145 PS noise at 200Hz. at 50mv the main tone is 145- log((4/0.05)^2)/log(2)*3 = 145- 38 = 107db higher than PS tone.
well I can measure it, I can hear it, that all. My setup is already more controlled than most people's, with super short 10cm well isolated rca cable, and battery powered E30 and laptop (relies on its own battery). the only thing connected to the power cord is this amp.The accumulated noise is 0.2-0.3uV. The PS noise is 60nV. So no, power supply noise is not the main contribution of the noise. It's the resistor thermal noise and the inherent noise of the opa1612 that is the main contribution.
Doesn't matter. If you have a loop it can even come from the air.well I can measure it, I can hear it, that all. My setup is already more controlled than most people's, with super short 10cm well isolated rca cable, and battery powered E30 and laptop (relies on its own battery). the only thing connected to the power cord is this amp.
yea. I see amirm's test it's a lot better, even with lower output full amplitude than Wolf's.Or it's -150dB ref to 2V in Amir's measurement. Equals to 0.064uV or 64nV.
I think some of the graphs are from using the previous power supply. And there's absolutely no way at this level it's audible. If you think your power supply is faulty you may contact seller and try a new one. That's all I can say because this is one of the most important aspects in the design.yea. I see amirm's test it's a lot better, even with lower output full amplitude than Wolf's.
My PS noise is similar to Wolf's. His spike is lower in the FFT because full amplitude is 4V.
His test is even worse as the noise is at 200Hz, so should be more audible than mine.
As @JohnYang1997 said good when genuine.But it is a lottery, its sound can vary considerably. I have two units with me right now and have tested other two. 2 were bought from Samsung online store (at the same order), one came with my Galaxy S9 and the last were from a S8. The unit from S9 and one from Samsung's store sounds very similar (a little less bass, but keeping the sub bass and more piercing treble - quite annoying). The other unit from Samsung has the best sound - just as before, but less treble. S8's unit has a lot of bass and a little less of treble.@half_dog what do you think about AKG E0-IG955? Good, decent, sub-par etc?
And how would you get rid of such a loop?Doesn't matter. If you have a loop it can even come from the air.
Also you can do a calculation of how high of an noise that's going to be audible.
And how would you get rid of such a loop?
Loop only exists when you measure things. The headphone is open end essentially.And how would you get rid of such a loop?
As soon as I got the notification from them instantly ordered L30+E30. Now I just have to wait so more days.Audiophonics has L30 again in stock.
They have send mine today