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Topping DX7 Pro DAC and Headphone Amp Reviewed

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amirm

amirm

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I had measured the filter response but forgotten to include it. It is now in the review:

index.php


I like #1.
 

Veri

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I had measured the filter response but forgotten to include it. It is now in the review:

index.php


I like #1.
That's odd Amir. Min and lin phase fast, min and lin phase slow are usually right next to each other. Here Apodizing and Linear Fast seem to have been switched. Documentation mistake, or is the corresponding filter programmed wrong?

Filter #1 appears to be apodizing in any case, using previous measurements (for example sabaj d5) as a reference. It has the same 'trail' pattern at the end, too..
 
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The UI for filter is a bit hard to use as it seems when you click the option, it already advances to the next one. But maybe it doesn't. Shift them up or down one and see if they are right. I did measure them in sequence and typed in what the manual says.
 
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I believe they switched #1 and #5 then. Possibly.
Ran them again and to my eye they look the same:

1571517566442.png


So unless you see a difference, either the manual or the firmware may be wrong.
 

gvl

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Ran them again and to my eye they look the same:

View attachment 36471

So unless you see a difference, either the manual or the firmware may be wrong.

I'm trying to grasp the concept of how white noise can be captured or produced at 44.1khz sampling. Isn't white noise spectrum infinite and we only have up to 22.05kHz per Nyquist?
 

MediumRare

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I had measured the filter response but forgotten to include it. It is now in the review:

index.php


I like #1.
Assuming any of us over the age of 25 cannot hear beyond 17k (at a stretch) wouldn't the brick wall filter sound the best due to removing the most energy above 20k from the amplifier load?
 
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I'm trying to grasp the concept of how white noise can be captured or produced at 44.1khz sampling. Isn't white noise spectrum infinite and we only have up to 22.05kHz per Nyquist?
The noise is not recorded, but created in digital domain. I can have a 0 and 32,000 next to each other and with it, have infinite bandwidth for example. All I need is a computer program to create it. The pixels you see on this forum likewise have infinite bandwidth and violate Nyquist.
 
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Assuming any of us over the age of 25 cannot hear beyond 17k (at a stretch) wouldn't the brick wall filter sound the best due to removing the most energy above 20k from the amplifier load?
It could but the level of aliasing is very small so allowing a bit of it while preserving the full bandwidth is not a bad idea.
 

gvl

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The noise is not recorded, but created in digital domain. I can have a 0 and 32,000 next to each other and with it, have infinite bandwidth for example. All I need is a computer program to create it. The pixels you see on this forum likewise have infinite bandwidth and violate Nyquist.

Gotcha. Thanks.
 

dmac6419

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Oh one note: this is a new product. I am not vouching for its reliability. Please don't buy it early and blame me if there are issues. :) My unit is working flawlessly so far.
So I need your advice Amir,whatever you recommend I'm gonna buy,should I get this?good stuff is coming at me too fast!!!
 

AndrewDavis

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This is going to be one of those DAC/AMPs that people buy just for the DAC, like the RME ADI-2.
 

antdroid

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@amirm is there any chance you can run measurements using the 4.4mm output? Output impedance being my biggest question mark on this unit. Otherwise, I'd love to have one of these at work. :)
 

MediumRare

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This is going to be one of those DAC/AMPs that people buy just for the DAC, like the RME ADI-2.
To address/clarify this issue (i.e, The DAC is great but the headphone amp section not so much), @amirm, could you an appendix to this review that evaluates the headphone amp performance in the context of other headphone amps, including the SOTA competition?
 
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amirm

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So I need your advice Amir,whatever you recommend I'm gonna buy,should I get this?good stuff is coming at me too fast!!!
I am going to use it for my everyday unit. You have to decide for yourself. :)
 
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@amirm is there any chance you can run measurements using the 4.4mm output? Output impedance being my biggest question mark on this unit. Otherwise, I'd love to have one of these at work. :)
I measured the output power versus distortion+noise already (50 ohm). I don't have a fixture for impedance measurement but it is going to be 2X higher.
 
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