Gustard X16 Balanced MQA DAC Review

[Pdxwayne]

DAC connected through rca, regardless if it is switched on or off. It pushes through a buzzing sound to the amplifier, which is audible turning up the receiver to -40 db.
So dissapointing seems like a bad power circuit design.

How do you connect the source to the DAC? Computer USB? I wonder if you have ground loop issue.

I am using node2i via toslink and coaxial, do not have such issue.

 

[Pdxwayne]

Just an update, I have had a reply from Rory at Benchmark and their DAC will do exactly the same, spit out DC at on and off so no better for my amplification, apologies to @gustard for saying it was shoddy, I will now pop off and eat some pie......... Oh and for reference it still does it at switch on through XLR with my setup, which is probably fairly not typical.

Hmm, I connected xlr to my subs, my subs did not make any noise when switching x16 on or off.

 

[ABall]

Hmm, I connected xlr to my subs, my subs did not make any noise when switching x16 on or off.

Yes I wouldn't expect anything different going XLR to XLR, there are not many amplifiers out there like mine, well there are but in the great scheme of things, most manufactures design with a DC blocking capacitor with a single ended input, my amps dont have DC protection, they have a DC servo which allows them to have no capacitors in the signal path, certainly not in the input or output anyway, the speakers are connected directly to the output transistors, they have the usual zobal network but nothing stopping DC passing right through, in fact they amplify DC the same way they do music so its very bad for my speakers.

 

[Pdxwayne]

Yes I wouldn't expect anything different going XLR to XLR, there are not many amplifiers out there like mine, well there are but in the great scheme of things, most manufactures design with a DC blocking capacitor with a single ended input, my amps dont have DC protection, they have a DC servo which allows them to have no capacitors in the signal path, certainly not in the input or output anyway, the speakers are connected directly to the output transistors, they have the usual zobal network but nothing stopping DC passing right through, in fact they amplify DC the same way they do music so its very bad for my speakers.

I see.

When I was using KTB as DAC, with RCA connect to my sub, I could hear large pop when mistakenly power on or off the KTB. So at least for my sub, RCA have no protection either.

 

[gofry]

How do you connect the source to the DAC? Computer USB? I wonder if you have ground loop issue.

I am using node2i via toslink and coaxial, do not have such issue.

usb but does the same when there is nothing connected at all.

Another question though: is there a way to switch to dac only mode and go with fixed volume control without pre-amp mode?
the guide says push the dac button for 3 secs but that practically does not do anything.

 

[ABall]

usb but does the same when there is nothing connected at all.

Another question though: is there a way to switch to dac only mode and go with fixed volume control without pre-amp mode?
the guide says push the dac button for 3 secs but that practically does not do anything.

It doesn't have a preamp, like most dacs it attenuates the digital signal level at the output, just turn it up to max, it may have a way to disable attenuation but it won't sound any different.

 

[Pdxwayne]

usb but does the same when there is nothing connected at all.

Another question though: is there a way to switch to dac only mode and go with fixed volume control without pre-amp mode?
the guide says push the dac button for 3 secs but that practically does not do anything.

Amir often mentioned using xlr from DAC to amp would avoid ground loop issue. In your case I am not sure how to solve it. Maybe some other members can offer advise.

 

[gofry]

Not a groundloop issue.

Amir often mentioned using xlr from DAC to amp would avoid ground loop issue. In your case I am not sure how to solve it. Maybe some other members can offer advise.

i don’t think it is groundloop. Connected the dac to the a different loop entirely in another room and connected w a looonh rca and still the same.

 

[Pdxwayne]

Not a groundloop issue.

i don’t think it is groundloop. Connected the dac to the a different loop entirely in another room and connected w a looonh rca and still the same.

How about to another amp?

So far I have tried RCA to Topping L30 and to Parasound A21 stereo amp. No noise.

 

[ABall]

Not a groundloop issue.

i don’t think it is groundloop. Connected the dac to the a different loop entirely in another room and connected w a looonh rca and still the same.

All ring main circuits share the earth, if you realy want to isolate ground loop problem just to test then get another iec cable, cut the earth pin, may have to put a new plug on and test again. Not suggesting you run it full time without an earth....

 

[gofry]

All ring main circuits share the earth, if you realy want to isolate ground loop problem just to test then get another iec cable, cut the earth pin, may have to put a new plug on and test again. Not suggesting you run it full time without an earth....

I think the yamaha amp does not even have an earth pin at all

example

 

[Pdxwayne]

I think the yamaha amp does not even have an earth pin at all

example
View attachment 109896

Hmm, the Yamaha have inputs from other devices with ground? Try remove all other inputs to Yamaha? If I remember correctly, typically people found that the issue is related to cable TV connection....

 

[ABall]

I think the yamaha amp does not even have an earth pin at all

example
View attachment 109896

No it doesnt..... but I will say I have an Intel Nuc that runs through my Onkyo AV amp, the av amp has no ground just like yours but I was getting buzzing when I watched movies until I cut the plug off the Nuc and put a new plug on without an earth, the funny thing is the Nuc is DC powered so that wasn't earthed, it was just the power supply. Anyway cutting off the earth stoped the noise.

 

[ABall]

Unrelated but I wouldn't dream of putting my X16 through my Onkyo.

 

[jsm]

try to isolate the mass of just one RCA plug with some tape just as a test

 

[gofry]

Uhh folks...it was the cable tv. Deatched. No noise no pop, nothing ‍
I see the advice now from you as well. Thanks a lot. Seems like I need an isolator for the incoming cable.

 

[boblinds]

Just an update, I have had a reply from Rory at Benchmark and their DAC will do exactly the same, spit out DC at on and off so no better for my amplification, apologies to @gustard for saying it was shoddy, I will now pop off and eat some pie......... Oh and for reference it still does it at switch on through XLR with my setup, which is probably fairly not typical.

Good idea. Pie makes everything better. I think I'll join you.

 

[ABall]

Good idea. Pie makes everything better. I think I'll join you.

Doesnt taste so good when it's a humble pie....

 

[Dannemand]

Doesnt taste so good when it's a humble pie....

Don't worry, I think you handled this perfectly

 

[Library Detective]

Hi all, sorry if this is a daft question... my Gustart x16's usb, optical and coaxial inputs are all in use. I'd like to connect a pi4 (running piCorePlayer) to it, is there an easy way to connect the pi using the IIS or the AES inputs?