[Reactcore]

I've been searching the net and it seems to me there's only 1 2-channel DAC chip and it's using some "trickery" to convert the 2 channel signal into balanced. Is this correct?

I only need the DAC feature. Thanks

True. it has one DAC chip feeding a balanced Amp section.

 

[mrjayviper]

True. it has one DAC chip feeding a balanced Amp section.

But it also has a balanced output at the back. I'm guessing the "trickery" extends there (I think that's called IV converter?)

 

[Reactcore]

The amp is a 2 stage design.. after the 1st stage it goes balanced to xlr pre and to HP amp stage

 

[BlackOWL]

Hi everyone. Now I have Hi-X60 headphones powered by Lake People G111 mk2 and Soncoz LA-QXD1 DAC. How do you think, should I replace my stack with CMA 400i or replace just a DAC with SMSL SU-10 to get more clarity, control and punch?
CMA 400i is twice cheaper, but is it really good? Also I read about problems with this model.

I am willing to consider purchasing a CMA 400i in Europe. Or purchasing a faulty device to try to repair and experiment.
...or go to the max with Twelve Master?

 

[Reactcore]

Mine still works fine after 4 years.
I havent heard much difference in SQ between it and the twelve.

Theres also the CMA eighteen released

 

[M0xie]

So i figured the cause for the usb dropouts.. after it happened more often i went searching and found the voltage of the digital part was unstable and falling below 7v. (Normally above 8v) one of the rectifier diodes was running hot so i replaced all 4 for higher current rating. No issues for weeks now It seems its a design flaw so others might benefit too if they have them replaced.

For future visitors dropping here with the same problem, Reactcore's fix worked! I replaced the 4 diodes in this picture and I got rid of the popping noises of the Questyle and didn't have to throw it in the bin.

Actually, in my case it wasn't just popping, over the span of a few months the pops were happening more frequent to the point the Questyle was unusable, and I also had USB device disconnects from the PC. At first, power-cycling it would temporarily fix it, but in the end the driver would appear disconnecting / reconnecting and the DAC popping a few seconds after turning it on. It happened both on DAC and AMP, so both headphones and XLR, and it happened even when USB input on the back wasn't plugged-in.

I didn't take the PCB out (too many connectors and screws), just removed the top and disconnected the power connectors close to the 4 diodes. Both power connectors went back without issue, and didn't even have to remove the heat-shrinking sleeve on them. The diodes are SMD (surface mounted), so you'll preferably need: a good soldering iron (450C+ for desoldering because the old solder is a high temp, factory-grade one), small soldering tip (1-2mm), copper desoldering wick, maybe a liquid flux pen, good solder (thin, preferably one that contains a small part of Cu or Ag), a lamp (bonus if it's a magnifier with LED lamp included), tweezers, q-tips and isopropyl alcohol for cleaning the flux. Even with all these I did a semi-poor soldering job and diodes went a little side-ways because they're so small and hard to work with. Be careful not to touch the adjacent power caps close to the diodes with your iron and damage them. Or you could just take it to a qualified electronic engineer but lose the sense of victory of doing it yourself

I ordered 5 different models of 1N400X-type diodes hoping to use ones with lower recovery time (25-250 ns), but only the more generic ones were small enough / same size of the original ones so went with those - DO214AC / S1J Si-Rectifier 600V 1A SMA from Fairchild Semiconductor (600V reverse voltage, 1A forward current, 1.8us recovery time). It doesn't matter, they are fine. Probably the original diodes were quite low grade. Or maybe I have electrical problems in my house which made them to fail, no idea.

 

[Reactcore]

Even with its quirks its a fine sounding piece of kit thats overlooked by many.

I still like its small form factor.
Questyle should make a follow up on this aside the CMA18

 

[Questyle]

Certainly an idea! I'll toss that to the engineers and CEO, and let them ponder it over.

 

[SilentP11]

Hey Guys, I recently bought the CMA 400i and I just can't make the exclusive mode run with Tidal. I installed the Driver from their website, I checked the advanced sound settings in Windows 11, everything related to the device bypassing the system is enabled.
My other Dac works just fine, and I don't have any ideas how I can make it run on the questyle. Maybe someone had similar problems or an Idea where to look next and could help me in that regard, would be much appreciated.