Soncoz LA-QXD1 Balanced DAC Review

[Brab]

Thanks for setting me straight. I have deleted the offending post. The forum remains unsullied.

 

[Brab]

Just noticed that the coax input is subject to external interference, e.g. if I switch my phono stage on or off, there is a momentary skip when playing a CD. There is no interference when the USB or optical input is used. Any idea why, and how to fix it?

 

[hyp]

Update:

After my previous posts regarding my broken LA-QXD1, I really didn't have any expectations for getting the DAC fixed. Having read other posts detailing similar failures, as well as noticing that I was out of warranty for over a year, my confidence in Soncoz doing anything was pretty much zero. (It'd been over 2 years since I made the initial purchase. With the warranty period being 1 year, I assumed Soncoz wouldn't do anything and just pass the issue on as "out of warranty", as most companies would've done.)

As you can imagine I was pleasantly surprised when @EMMA from Soncoz reached out to me to discuss the DAC. After several emails back and forth, they decided that as long as the problem was caused by the PCB design flaw of the first batch (the electrostatic discharge issue), they would fix the DAC and send it back to me, completely free of charge! This was incredible news! I don't mean to be rude, but I honestly didn't expect a "value-oriented" audio company from China to offer this. This is the kind of customer service I would expect from very high end audio products.

So I bundled up my LA-QXD1 and sent it to Emma 2 months ago. Yesterday, I finally got it back. After plugging it in and testing out both the XLR and RCA outputs, I can happily say that Soncoz have delivered spectacularly on both their technical and customer service front.

For now I've nothing but praises for the good folk at Soncoz for stepping in and taking responsibility for their products, even after the warranty period had long passed. I'd be happy to make another purchase from them in the future.

-Hyp

 

[Labjr]

I still would never buy anything from Soncoz. Way too many issues. Customers end up being the beta testers for designs which weren't thoroughly tested before going into production.

 

[Brab]

Can you power this unit from the USB input of an audio receiver?

 

[staticV3]

@Brab If the USB port on the receiver can supply at least 1A, then yes. What receiver are you thinking about?

 

[Brab]

Thanks for your reply. It's a Pioneer SXN30. I haven't been able to find any info on the USB port.

 

[staticV3]

Thanks for your reply. It's a Pioneer SXN30. I haven't been able to find any info on the USB port.

From the manual:

USB 1.1 is 0.5A or more. So the receiver may be able to power the LA-QXD1, but it's not guaranteed.

However, even if the receiver can output enough power, it does not support audio output to external DACs via USB, nor does it have other digital audio outputs.
So while you may be able to power the DAC off the receiver, you cannot play music on it from the receiver.

 

[Brab]

Thanks again. I just need it for the power.

 

[staticV3]

Thanks again. I just need it for the power.

In that case, try contacting the Pioneer support and asking them what's the maximum current draw via USB before the receiver will cut the connection.

Or, if you have the SX-N30 at home, then you can test the max current draw yourself using a USB power meter like this.
Just plug it into the receiver, then plug whatever USB accessories you have at home (external hard drives, phones, tablets, etc) into the meter and see what the maximum current is that they will draw.

Alternatively you can plug a variable USB load like this into the power meter, or get a variable USB load with built-in display like this,
Both will allow you to slowly increase the current draw until the receiver triggers over current protection.

 

[Brab]

I used an android app called Ampere to check the output of the USB input. The app is probably not that reliable, but I think it's enough to show that the amperage is well below that required by the Soncoz. Thanks again for all your advice.

 

[monochromedout]

My unit has had a dead RIGHT channel for a couple years. I found it on my bookshelf and decided to mess with it a little as it still drives me crazy that the unit crapped out all on its own just outside of my return window. After opening it up and probing around, I've come to find that when I pull my headphone jack out just right, the LEFT channel dies and the right channel comes to life. If I mess with it further I can get serious static on both sides.

This happens through XLR or RCA outputs so it's something before it reaches the output jacks maybe? This happens (obviously) with the unit assembled hence why I decided to crack it open.

Is this some kind of strange grounding issue that I can fix without having to throw this unit away? Any electrically inclined can tell me what I need to check with my multimeter? Any component that I can replace? I know how to build a throughhole guitar pedal so don't doubt I could tack something on. Would love to have a balanced dac back in action with my thx aaa 789 again!

 

[gvl]

There are four opamps in the lower part of the board as shown. See if the top left, or any other, is hot. Careful, don’t burn your finger. If it’s hot you need to replace it.

 

[Topaloff]

First you need to check the cables. You can use a multimeter or simply replace the cables with known good ones. You can also try swapping the RCA connectors. Maybe there is a break or bad contact in the 3.5mm jack.
The next thing to do is to check the quality of the soldering visually and at least measure the voltages of the capacitors on the right side of the regulators 7812 and 7912. The voltages should be at 12 volts.

 

[turbotuff]

Just noticed that the coax input is subject to external interference, e.g. if I switch my phono stage on or off, there is a momentary skip when playing a CD. There is no interference when the USB or optical input is used. Any idea why, and how to fix it?

I am also having this issue. Anyone have a fix?

 

[TwoEars]

Oh, crap. I just bought this DAC on Ebay yesterday for $219 (silver), which has been shipped from China. so I can't cancel. I should have read through all the postings before buying just from the measurements.

 

[KLang1]

There are four opamps in the lower part of the board as shown. See if the top left, or any other, is hot. Careful, don’t burn your finger. If it’s hot you need to replace it.

You mean those two to the right of the crosshair?
My left channel is producing static since yesterday evening.

 

[gvl]

two to the right of the crosshair

Yup. The bottom one as pictured often gets damaged by static electricity. It’s OPA1612 iirc. Looks like both are hot, the one on the top is not a common part, I couldn’t find it from the major US online part vendors.

 

[turbotuff]

My unit just lost the left channel as well. Very frustrating.

 

[Labjr]

Yup. The bottom one as pictured often gets damaged by static electricity. It’s OPA1612 iirc. Looks like both are hot, the one on the top is not a common part, I couldn’t find it from the major US online part vendors.

Maybe Arrow has stock? I've bought parts direct from TI too.