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FX Audio DAC-SQ3 Review

GimeDsp

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wish more DACs that can act as a preamp would offer volume buttons - it's an essential feature for a preamp imo
True, this DAC will be used with many small amps,
My topping PA3 lists input
I found these specs for the PA3
Input sensitivity: 0.6Vrms (4Ω); 0.9Vrms (8Ω)

I believe I need to keep the DAC output below 1v to avoid clipping with loud source signals.

If you were to hook this DAC up to a PA3 or other chip amp and run it at 100% at the source that could cause issues.
Better to leave the source fixed to avoid clipping then use amp or DAC volume I thought.
 

PeteL

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True, this DAC will be used with many small amps,
My topping PA3 lists input
I found these specs for the PA3
Input sensitivity: 0.6Vrms (4Ω); 0.9Vrms (8Ω)

I believe I need to keep the DAC output below 1v to avoid clipping with loud source signals.

If you were to hook this DAC up to a PA3 or other chip amp and run it at 100% at the source that could cause issues.
Better to leave the source fixed to avoid clipping then use amp or DAC volume I thought.
It's not exactly that. What It means is that you can get the amp to full power with an input of 0.6 or 0.9 VRMS, meaning it doesn't clip if volume of your amp is at max under these condition. Having higher input than that, means you CAN clip the amp if you push the volume knob too high, but just turn down the amp volume knob. It won't clip. You don't have to keep the DAC output under 1V, it's totally fine to keep your source at 0DBFS and attenuate with the analog potentiometer.
 
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GimeDsp

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It's not exactly that. What It means is that you can get the amp to full power with an input of 0.6 or 0.9 VRMS, meaning it doesn't clip if volume of your amp is at max under these condition. Having higher input than that, means you CAN clip the amp if you push the volume knob too high, but just turn down the amp volume knob. It won't clip.
Ok, so even if it doesn't start clipping till 1.8v or so that still leaves room for issues, mostly on compressed media like lots of streaming or other sources that push our a loud signal.
 

PeteL

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Ok, so even if it doesn't start clipping till 1.8v or so that still leaves room for issues, mostly on compressed media like lots of streaming or other sources that push our a loud signal.
I'm not fully sure you understood tough, in 4 ohm, the amp will start clipping at 0.6V, but that's 0.6 Volts after the potentiometer that is specifically there to attenuate the input. It comes down to where you prefer the attenuation, there are issues both ways. Different. In all cases, If you clip the amp, it means that you bought an amp that's not powerful enough for the level you need to listen at.
 
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GimeDsp

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I'm not fully sure you understood tough, in 4 ohm, the amp will start clipping at 0.6V, but that's 0.6 Volts after the potentiometer that is specifically there to attenuate the input. It comes down to where you prefer the attenuation, there are issues both ways. Different. In all cases, If you clip the amp, it means that you bought an amp that's not powerful enough for the level you need to listen at.
That's good to know.
So with computer/DAC at max volume and amp at zero, the input is seeing zero voltage and I will only clip if I need to turn up past what the input can handle.
 

PeteL

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That's good to know.
So with computer/DAC at max volume and amp at zero, the input is seeing zero voltage and I will only clip if I need to turn up past what the input can handle.
Yes
 

tcli

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Strange that they keep a dip-8 opamp :
FXaudioSQ3.jpg
 

CedarX

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Nice one. It almost makes topping d10 look expensive :)
It's time for small cinese builders like FxAudio to get their hands on one of these APxxx analyzers :)
When that will happen it will be just a matter of time before they will deliver good measuring dacs at low prices and SMSL/Topping will start having some competition.
They seem to own or have access to an AP—from AliExpress description:
0CB34E12-2E18-4949-B972-7FF499A89CD2.jpeg
 

Gremlins

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Hello all, i read the 3 pages and so far there has been no answer to a question posted 3 times : does the coax output is volume controlled?

This feature is what would make this device really really interesting.

No other devices control volume at coax outputs (unless very expensive gears, and 01st price is mini shd at 1000e )
 

Tangband

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Hello all, i read the 3 pages and so far there has been no answer to a question posted 3 times : does the coax output is volume controlled?

This feature is what would make this device really really interesting.

No other devices control volume at coax outputs (unless very expensive gears, and 01st price is mini shd at 1000e )
Yamaha wxc50 is volume controlled at spdif out ( toslink and electrical ) in ”pre amp mode” , but it does SRC to 48 kHz on every material. It sounds slightly worse than in ”player mode”. Cost about 300 dollars.

If this tested device have remote controlled volume-regulations on the digital out, that does not do SRC , Its really interesting for us who have active loudspeakers with digital inputs, such as Genelecs .:)
 

Gremlins

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Me i have hypex fusion plate amps and woyld love to fi.d a device that control volume i. Digital mode

The yamaha will limit quality from what i read on it
 

Tangband

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Me i have hypex fusion plate amps and woyld love to fi.d a device that control volume i. Digital mode

The yamaha will limit quality from what i read on it
We will hope that Amirm is reading this .
 

hestejoe

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Its really interesting for us who have active loudspeakers with digital inputs, such as Genelecs .
Realistically speaking, should one even expect to hear a difference whether a good set of Genelecs is fed with this at 107 dB SINAD vs one that is state of the art at ~120 dB? I would surely be surprised.
 

PeteL

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Realistically speaking, should one even expect to hear a difference whether a good set of Genelecs is fed with this at 107 dB SINAD vs one that is state of the art at ~120 dB? I would surely be surprised.
Maybe not, but that wasn't the question, 107 dB is for the DAC, those people intend not to use the DAC but use the one inside the Genelec. Since those already work in digital and have internal DSP. The Digital outs where not measured. And I'll add that the info that we can find online is not only sparse, but unclear and at times plain wrong...
 
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JSmith

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In the end, all the tolerance that they internally choose don't matter much, what matters is does what they sell match the specifications they advertise.
I agree, as long as the replacement part has a similar longevity spec.
If one accuse them of doing this must be able to back it up.
True, there's no point making wild accusations without evidence. That said, if more people gave permission for Amir to open up the items sent for testing for a teardown thread, then people could make their own visual comparisons on the internals. More people should also open up their devices and post pics of internals in general if this is a concern.



JSmith
 

gvl

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Hello all, i read the 3 pages and so far there has been no answer to a question posted 3 times : does the coax output is volume controlled?

This feature is what would make this device really really interesting.

No other devices control volume at coax outputs (unless very expensive gears, and 01st price is mini shd at 1000e )

I doubt it is. Volume control is typically handled on the DAC chip where it can be done with high precision in 32 bit space, the SPDIF transceiver gets its I2S input from the XMOS chip likely which is before the volume control. The isolation transformer for coax is a nice touch.
 
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PeteL

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I doubt it is. Volume control is typically handled on the DAC chip where it can be done with high precision in 32 bit space, the SPDIF transceiver gets its I2S input from the XMOS chip likely which is before the volume control. The isolation transformer for coax is a nice touch.
With all respect, there is a high res picture of the internals a few post up. Me I don't see a transceiver chip. I may be wrong, do you see one? It's a simple design. XU208 can output SPDIF directly, not only I2S. XMOS is easily capable of doing volume control too. Remember, we have only one input, USB. + there is an extra Artery Micro-Controller on the far left that I don't know what does but probably display and such. just looks like there is some conditioning in the trace to the connector, but it goes straight there. I may be wrong but XMOS can certainly handle volume control, all before the DAC chip. But obviously I don’t know exactly how they did, your Hipothesis is as good as mine.
 
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gvl

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Common sense tells me that doing any sort of fancier programming on XMOS than just bundling stock USB firmware on a sub $100 product with this type of bill of material is highly unlikely, but I’m prepared to be surprised.
 

PeteL

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Common sense tells me that doing any sort of fancier programming on XMOS than just bundling stock USB firmware on a sub $100 product with this type of bill of material is highly unlikely, but I’m prepared to be surprised.
Volume control and spdif transmit is part of the stock USB firmware.
 
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