This is a hardware review of FX-AUDIO DAC-X6 USB DAC. For measurement and listening tests go to this article: https://www.audiosciencereview.com/...c-compared-to-topping-d30-and-fiio-e10k.2097/
As noted in that review, this is an ultra low cost $58 DAC and headphone amplifier. They provide the overall block diagram thusly:
And that matches what is inside:
I have indicated with arrows the flow of signals. Following the USB input, we go into Via VT1603 USB interface. The digital data is then handed to Crystal Semiconductor CS8416 which is also the S/PDIF interface. The provides the serial interface to the heart of this device, the Cirrus Logic CS4399 DAC which costs about $6 in volume. The analog output then gets buffered through Ti/Burr Brown OPA2134. From there, this path splits. One goes to the rear RCA jacks and the other, to TI6120 Headphone amplifier. This path is rather optimal, keeping the analog output way away from digital path. Such is not true of RCA output which has to then travel way back to the back of the unit. This makes it more susceptible to noise pickup. In a larger enclosure, this could have been laid out more optimally.
Interesting to see a dedicated protection circuit IC (C1237HA). This guards against shorts in the headphone output causing damage to driver IC.
One of the concerns with Chinese products at these price point is usage of used or counterfeit parts. That concerns shows up clearly in this rusty switch:
It doesn't show up as well in the picture but that entire side is rusty red. Components like this would not rust so fast so my suspicion is that this is a used switch that lost its good life in another component. Or alternatively it is a poor quality switch as to rust so easily.
This story continues in another component:
We see the top of the capacitor is literally dented! Maybe it got damaged in manufacturing but whatever the cause, it doesn't inspire confidence.
At the other extreme, I was shocked to see an FX-Audio branded oscillator in there:
Maybe they have an employee with spare time and an engraver .
And oh, this is the revision number of the board in my unit:
Wonder what version 1 looked like.
They advertise high quality Elna capacitors in there:
Well, I see no sign of that. Here is what is there:
Even if it said Elna on it, I am not sure I would trust it.
The backside shows flux that is not cleaned and solder job that barely passes:
Summary
FX-Audio DAC-X6 is an impressive device as far as feature set and components at such low price. Underneath though it "smells" like low budget construction and suspicions of used parts. But what the heck, at these prices you could throw it away should it break. More money would have surely bought one better quality. My suggestion is to not open the box and look at it!
As noted in that review, this is an ultra low cost $58 DAC and headphone amplifier. They provide the overall block diagram thusly:
And that matches what is inside:
I have indicated with arrows the flow of signals. Following the USB input, we go into Via VT1603 USB interface. The digital data is then handed to Crystal Semiconductor CS8416 which is also the S/PDIF interface. The provides the serial interface to the heart of this device, the Cirrus Logic CS4399 DAC which costs about $6 in volume. The analog output then gets buffered through Ti/Burr Brown OPA2134. From there, this path splits. One goes to the rear RCA jacks and the other, to TI6120 Headphone amplifier. This path is rather optimal, keeping the analog output way away from digital path. Such is not true of RCA output which has to then travel way back to the back of the unit. This makes it more susceptible to noise pickup. In a larger enclosure, this could have been laid out more optimally.
Interesting to see a dedicated protection circuit IC (C1237HA). This guards against shorts in the headphone output causing damage to driver IC.
One of the concerns with Chinese products at these price point is usage of used or counterfeit parts. That concerns shows up clearly in this rusty switch:
It doesn't show up as well in the picture but that entire side is rusty red. Components like this would not rust so fast so my suspicion is that this is a used switch that lost its good life in another component. Or alternatively it is a poor quality switch as to rust so easily.
This story continues in another component:
We see the top of the capacitor is literally dented! Maybe it got damaged in manufacturing but whatever the cause, it doesn't inspire confidence.
At the other extreme, I was shocked to see an FX-Audio branded oscillator in there:
Maybe they have an employee with spare time and an engraver .
And oh, this is the revision number of the board in my unit:
Wonder what version 1 looked like.
They advertise high quality Elna capacitors in there:
Well, I see no sign of that. Here is what is there:
Even if it said Elna on it, I am not sure I would trust it.
The backside shows flux that is not cleaned and solder job that barely passes:
Summary
FX-Audio DAC-X6 is an impressive device as far as feature set and components at such low price. Underneath though it "smells" like low budget construction and suspicions of used parts. But what the heck, at these prices you could throw it away should it break. More money would have surely bought one better quality. My suggestion is to not open the box and look at it!