FDA: Alientek D8

A minor correction: this "DDX" thing is related only to the output PWM and has nothing to do with any processing or lack of it before output. So, yes, "Tone" is the only setting in D8 which bypasses the internal DSP, but "DDX" can be switched on or off in firmware regardless of the DSP settings. I suppose, in D8 it is always on.

thks for point-out DDX... Ok got it DSP.
 
Guys, I need a firmware for the XMOS version, help!

I've downloaded the driver from this site today:
Alientek D8 XMOS USB drivers and English: bravomail
works fine, but i''m not responsible if anything goes wrong :)

I have a few questions myself:

1) How to open the D8? I unscrewed all the screws, but the thing is still tight and not moving apart.
2) Which of the EQ positions i have to use to achieve the best sound? I assumed it was Flat, then read in manual, that it was Normal and someone suggested that it's Tone. I suspect the Tone is right, but it produces more bass than my Cyrus amp, so i'm not sure.
3) If i use weaker power supply (24v 3a), can it have impact on the sound quality (not the power)?
 
I've downloaded the driver from this site today
Driver is not firmware, these are two different things.

1) How to open the D8? I unscrewed all the screws, but the thing is still tight and not moving apart.
Pull off the turning knob, unscrew the front screws, then remove the front panel and pull out the white ribbon from the front panel socket (carefully!), then unscrew 4 rear screws and pull the rear panel with the PCB and the outer box apart.

2) Which of the EQ positions i have to use to achieve the best sound?
"Tone" is the most authentic (the least intrusive) EQ setting. Whether it is the best sound for you or not, only you can decide.

3) If i use weaker power supply (24v 3a), can it have impact on the sound quality (not the power)?
It should not until you try to get more power out of your amp then your PSU can provide to it.
 
What is it that makes it seem so to you?

By default STA326 alters volume smoothly when its Master volume register is updated. But in my case when I feed a tone to my Alientek D8 and then spin its control knob I hear clicks, which means that volume is changed in abrupt large steps. And that may mean that this register is not used. This makes sense from the designer's point of view, because it is much easier to tamper with the incoming digital stream at a single point than to update STA326 and some other chip controlling headphones' volume.

Also, changing the volume changes the height of the spectrum histogram on the D8's display, and this effect would come naturally if it is the incoming digital stream that is changed.
 
I am trying to ID afew of the SMD on D8, anyone knows what are these based on their print and pin#:
1. 4B2R - 5 pin
2. 6x1 - 3 pin
3. 2F75 - 6 pin
4. MOP - 3 pin
5. 775J - 3 pin

This probably is XC6204 - a 3.3V High Speed LDO Regulator with ON-OFF Control.

Thank you for the helpful lead!

High Speed LDO Regulator = is it a switching buck regulator or linear regulator? Interestingly its noise level is only 30μVrms at 10ma.

at 3.3v current output 150ma/each, can piggy back a-few together get higher currrent output?
 
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Bought one recently from AUDIOPHONICS, France, this month.
The analog input produces noise whether a source is connected or not.
The USB input also results in constant HISS, which is covered up by music, when potentiometer reads 20 or higher on the display.
The store says they are not aware of any hiss issues, and try to incriminate my source, a Samsung J7 (2016) smartphone.
Besides the hiss issue, I really enjoy the punch of this tiny audio amplifier. At low listening levels, unfortunately where hiss is loud and clear, my Jamo Alto speakers produce mid range and low frequencies I was not able to enjoy before. A final point : I had to use a laboratory 12 VDC power supply with the Alientek, in order to decrease the hiss to a tolerable level.
Any suggestions ?
 
With reference to AUDEO's suggestion of inserting an inductor between +VCC (25VDC) and +5V (from DC to DC converter), and his mention of allowing for at least 3 amperes, by applying Ohm's Law : Power = Voltage X Current one sees that the inductor is dissipating 20 V X 3 A = 60 Watts. It would means that half of the power supply's power would be wasted across the noise suppressing inductor. Has someone thought of another way of reducing that hiss ?
 
though bought the parts, yet to perform inductor surgery - having more thoughts for conviction bef doing so.

What: the suggested 3A inductor filters blocks off high-freq to supply +5V

Where does & how much current being drawn on +5V ?
Is it for control, logic, Xmos USB, spdif optical/coaxial; does these consumes 2-3 amperes?
 
Oh... I think wld just insert the 15uH inductor:
"Input power line" refers to the +Vin from the DC socket, and "5V DC-DC" refers to the 5V regulator +Vin, am i correct?

I am referring to the above comment. The +Vin from the DC socket stands at 25 VDC and the 5V regulator stands at 5V. There is a voltage difference of 20 V between the 2 points. Somewhere else among the posts, AUDEO suggested that the inductor should be able to take 3 amps. Once this is stated, it is a simple matter to apply Ohm's law : Power equals Voltage times Current.
Now, can someone confirm how the inductor is added to the existing circuit board ?
 
Oh... I think wld just insert the 15uH inductor:
"Input power line" refers to the +Vin from the DC socket, and "5V DC-DC" refers to the 5V regulator +Vin, am i correct?

do check with mod-originator AUDEO.

I am referring to the above comment. The +Vin from the DC socket stands at 25 VDC and the 5V regulator stands at 5V. There is a voltage difference of 20 V between the 2 points. Somewhere else among the posts, AUDEO suggested that the inductor should be able to take 3 amps. Once this is stated, it is a simple matter to apply Ohm's law : Power equals Voltage times Current.
Now, can someone confirm how the inductor is added to the existing circuit board ?

I believe 5V regulator was supply from another onboard SMPS (this SMPS was said to have caused the high-freq noise ripples), not directly from +Vin DC socket. Also voltage drop is by 5v voltage regulator, not by the inductor-mod (there is a little voltage drop due to inductance of inductor ~ nowhere near 20v). Thus this inductor just filter absorbs any high-frequency noise ripples turn it into heat to be dissipated. Also as mentioned, doubted 3A is needed for 5V to supply control logics, Xmos USB, Optical/Coax spdif, DAC.

to be sure, do verify with AUDEO.
 
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Before discussing further this point, one has to know how and where the inductor is connected, on the D8 circuit board.
On this capital point, the originator of that suggestion has not come forward.
Il this point is not ascertained, any further discussion is pointless. It is not a matter of believing, but of knowing and of applying known laws.
 
Before discussing further this point, one has to know how and where the inductor is connected, on the D8 circuit board.
On this capital point, the originator of that suggestion has not come forward.
Il this point is not ascertained, any further discussion is pointless. It is not a matter of believing, but of knowing and of applying known laws.

Like you say ~
It is not a matter of believing:

1- It is not +Vin from the DC socket that carries the high-freq ripple.
2- It is not at this pt, not as you consider 20v for Ohm's law
Filter inductor is not a voltage regulator, thus it does not drop 20v.

If you felt it is straight forward, go ahead then.
 
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