USB DAC...

jr@mac

I am not going to write a lengthy review by any means, but I will just say that this:

https://www.amazon.com/gp/product/B01HERNVFM/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

...is much, more better than this:

https://www.parts-express.com/dayton-audio-dta-120-class-t-mini-amplifier-60-wpc--300-3800

Granted, the FX Audio will not run a pair of speakers - but it is light years above the Dayton as a headphone amp. Currently playing Mark Knopfler's excellent "Privateering" from HD Tracks through the Akai cans Nick steered us to.

I have played this album many times through my Sennheiser/DTA combo before and this cheap Akai/FX Audio are on par with my cheap Sennheiser. Keep in mind my Senn's are an entry level model, I forget which. I swapped gear around a few times to be sure, but I do prefer the Aka/FX combo. 

Anyways, I have spent far more on way shittier SQ. 

dcibel

Did you mean to link to the Dayton DTA-120? They're not exactly similar products, one is a DAC/preamp, the other is a power amp.

Assuming you're just comparing the headphone output, how much does the sound worsen when you run your new FX DAC through the Dayton amp and plug your headphones in, compared to plugging your headphones directly into the FX DAC? If it sounds about the same, then you can assume that your previous source feeding the amp was the weak link.

jr@mac

Let us just assume, for the sake of argument, that I was using a nice DAC to feed the (deliberately linked to DTA-120) for purposes of this very brief review. Let us also assume that I have used the same DAC in the past to connect to a wide variety of gear. Since I am not interested in pursuing this further, let us also assume this is actually a DAC that has had some pretty glowing reviews.

Take the brief review for what it is worth, or leave it. 

dcibel

I'll leave it. I'm sure the FX is a great product, but the comparison makes no sense to me. Compare your new DAC to your old DAC, not your new DAC to your power amp. You seem convinced that the Dayton's headphone output is poor, and it probably is, but it sounds like you didn't make a comparison by plugging it into the new DAC.

ani_101

I listen on bluetooth, no DAC needed, Blutooth is capable all by itself to ensure no SQ survives

JasonP

I wonder what it looks like on the inside, but that FX-Audio DAC is using at its core a Cirrus chip that is also in many higher end audio components. Marantz and Oppo crands come to mind.

dcibel

JasonP said:

I wonder what it looks like on the inside, but that FX-Audio DAC is using at its core a Cirrus chip that is also in many higher end audio components. Marantz and Oppo crands come to mind.

There's plenty of images of the guts online, it looks like a pretty nice unit.

Tom_S

This thread is timely - I've been looking at the X6. I'm trying to find an inexpensive DAC that will work with my iPhone 6s Plus. It doesn't need to be portable, just tucked away on my desk at work. But searching for info on what devices work with ios 11 isn't shedding much light on budget DACs yet.

jr@mac

In any event, it is a sweet little headphone amp, flawed testing aside 

Bryan@MAC

dcibel said:

JasonP said:

I wonder what it looks like on the inside, but that FX-Audio DAC is using at its core a Cirrus chip that is also in many higher end audio components. Marantz and Oppo crands come to mind.

There's plenty of images of the guts online, it looks like a pretty nice unit.

Here ya go:

https://www.head-fi.org/threads/fx-audio-dac-x6-2016-release-potential-sub-100-king.809203

dcibel

This review was so compelling that I ordered one lol . I had actually been looking for something like this since my old DAC DIY project started having issues, and I just haven't had the energy to try and repair it. For the past while I've been using a Focusrite Scarlet 2i2 that I purchased as a portable interface for taking measurements, but it also works fine as a simple external soundcard, and I like that it has a seperate volume control for the headphone jack. However, while it sounds just fine, it isn't quite as resolving as my previous solution which was a very modified Zhaolu D2.5.

The price was right on the FX Audio unit, unfortunately Amazon Canada doesn't sell it, but I ordered from ebay for CAD$75, which is about 1/4 of the price of the Sabre DAC I was looking at.

My headphones are Master & Dynamic MH40, which probably deserve better than the Focusrite 2i2 headphone jack.

Kornbread

   Boy has a Shitt dac and the only surviving PE Bravo tubed headphone amp.  It makes for an enjoyable sound.  I've been using the same Aune x1, dac/pre/headphone amp for several years with my Grados.  More revealing than his combo, but his sounds so luscious.  One of these days I'll pick up a Shitt headphone amp to finish his Shitty combo.      

ani_101

dcibel said:

My headphones are Master & Dynamic MH40, which probably deserve better than the Focusrite 2i2 headphone jack.

Nice, I have the MH60. It is the wireless blutooth one! Though it is one of the better implementation of AptX, and has a very nice DAC and amp built in....

dcibel

I highly recommend the MH40. My only complaint is the weight, it will fall off my head if I try to be mobile with them on, but for sitting at the computer, excellent. Fantastic build quality, comfort and sound. They have just the right tonality for me.

I also have a pair of Sennheiser Momentum s (over ear model), but they just sit on the shelf now collecting dust.

ani_101

I like the MH60, it is lighter than the MH40 despite having gained an amp, DAC, bluetooth and batteries. I agree regarding the build quality, all metal and leather, and it does stay put on my head. It retains the MH40 sound signature and quality, but manages to squeeze in a bit more mid and treble clarity. Very little difference between wired and wireless. I do recommend it, but it is pretty steeply priced.

I have it in gunmetal and black.

Tom_S

After more Googling, I'm not optimistic about the X6 working with my iPhone. There are not many budget guaranteed-to-work options for ios besides Fiio products. There is the Focusrite iTrack Solo...but I agree with dcibel on the Focusrite 2i2. It's smooth enough to be enjoyable - it measures pretty darn flat. But even compared to my outdated Musical Fidelity X-ACT dac, it's missing that intangible spaciousness. 

Tom_S

I ordered an X6 last night! I picked up a USB adaptor for my iPhone and got 3 different devices to work through a powered USB hub. Knowing that, I am now optimistic the X6 will connect without any issues...at least until the next ios update.

Bryan@MAC

Tom_S said:

I ordered an X6 last night! I picked up a USB adaptor for my iPhone and got 3 different devices to work through a powered USB hub. Knowing that, I am now optimistic the X6 will connect without any issues...at least until the next ios update.

Did you get the Apple adapter?  Can you link to it?

Tom_S

Yep the Apple MK0W2AM/A from Amazon. I'm sure Best Buy has them too. It seems ridiculous to spend almost $40 on a certified smart-dongle, but what can you do? Apple has you by the gonads! I should have my X6 on Friday - my fingers are crossed!

Silver1omo

Secret Santa ordered one of the FX audio units. I just need to wait until february :P

dcibel

Unfortunately still waiting for my xmas present from myself. It's been coming from China "en route to Canada" for a week and a half now.

Silver1omo

Not much, I got some cable sleeving from Germany and just had to wait for 6 and a half weeks. 

dcibel

Finally, This DAC has made it through customs and should be here around thursday, just in time for xmas!

I dug up my old highly modified Zhaolu D2.5 (AD1852), it still works however I had salvaged the output stage for another project, so it has nothing after the output filter stage, definitely no high current headphone amp to do a direct comparison with headphones to the FX-Audio. I do have a few LM4562 in the bin and a pair of BUF634, maybe I can whip something up on a breadbaord for testing.

The only bad thing I saw when looking at info of the FX-Audio DAC-X6 online was the OP275 used in the headphone stage appears to be a mediocre op-amp, curious why it is used here. I do have a LM4562 in SOIC package, I may try a swap after reviewing the circuit, and perhaps a few capacitors along the way if needed.

dcibel

Its here, huzzah! Just plugged in, sounds quite good, definitely a step up from the Scarlet 2i2. As a comparison, there is more prominence in the high end, more clarity overall where the Scarlet sounds a bit "mushy" by comparison. 

I am finding a slight sibilance in the Treble, perhaps just because it's more prominent now, well see if I still feel the same after a few days of use.

My biggest complaint out of the box is the length of the power cord. Its barely 3ft which gets from a power bar on the floor to the desk top and no further. It is just a 12V DC supply, so I'll either find a suitable replacement or DIY a fix for this problem.

And if anyone is curious, yes it works fine in Linux as a USB device, though I had to make sure the output is set to spdif for the volume control to work. Minor detail.

Under Windows 10 the situation is actually worse, as a USB device the volume control does not work at all, and I got one heck of a surprise when I plugged in my amp and found that the volume control on the DAC itself is only for the headphone out, the line out at the back is at full volume all the time!

Tom_S

I definitely agree about the wall-wart power cord. Too short for a desktop unit. I'm also curious if using a power supply with more available current and stiffer regulation will make any sonic difference. I guess I hadn't noticed the treble issue, but I'm just feeding it Spotify from my phone. The Creative Aurvana headphones I use at work must be really easy to drive because I can barely move the volume pot 3-4 clicks before it's getting too loud. 

dcibel

Cracked the DAC-X6 open today to inspect it, and found that a 100uF cap next to the DAC IC was not soldered on one side, the lead was loose in the hole. Fixed that problem immediately. The rest of the board looks pretty decent. The power regulation is nothing fancy, there's a couple LM78XX,LM79XX regulators and a LM317 adjustable regulator with a trim pot, this one is set to 9V from the factory. Some ME7660 charge pump converters are used to create negative voltages from the single 12VDC wall wart supply. Parts quality is very good overall, the +/- analog voltages have 3*470uF Panasonic FC capacitors, little to complain about there, though there isn't any little 0.1uF poly bypass caps that you often see littering the PCB.

The main op-amp in the chain is nice in that it is a DIP package with a socket, so swapping for a different part is simple, noth that the OPA2134 is a bad choice by any means. Unfortunately they did not supply a DIP package or socket for the headphone amp, the OP275 used here is a SOIC. Why there isn't another OP2134 here is beyond me.

Some pretty blue Elna caps are the DC blocking, unfortunately with this device being so small it would be difficult to replace them with a poly cap. A second pair of Elna caps find their way towars the headphone amp, reviewing the circuit it looks like they can be safely removed (bypassed)unless for some reason your device plugged into the pre-out is backfeeding some DC voltage. With nothing connected there is 0V on both sides of these caps (these are C86 and C91). You'll want to leave C77 and C87 in place.

Tom_S

"found that a 100uF cap next to the DAC IC was not soldered on one side, the lead was loose in the hole.

Wow - so much for QC. Maybe I need to crack mine open too. 

Thanks for your explanation of the circuit on this. I had read on a Head-fi thread that changing the voltage on that LM317 rail could improve the sonics. 
https://www.head-fi.org/threads/fx-audio-dac-x6-2016-release-potential-sub-100-king.809203/page-6

I have learned to take most of these "mods" with a grain of salt. Do you have any thoughts on this one?

dcibel

That mod sounds like a bunch of nonsense. It looks like the guys over at head-fi have absolutely no electronics experience and are just swapping parts and messing with this and that cap all willy-nilly without any real thought. By dropping that voltage to 8V you'll literally be dropping the voltage supply of one side of the analog section to 8V, while the other side will remain at 9V. It makes no sense and all the parts on the board should be perfectly happy at 9V. However, its easy enough to try for yourself if you have a multimeter, simply measure the voltage at the LM317 regulator and tweak the pot. You can even do this one with your headphones on

Tom_S

Thanks for your input. That's pretty much what I figured. I have not opened my x6 up yet, but probably will, based on your finding the non-soldered cap. It sounds pretty good to me as-is with the phones I using at work. I'm not motivated to change anything unless it's a well documented (with actual measurements!) circuit mod.

Thanks!

Silver1omo

I have not received mine, but my friend tested it and the wall-wart is really a PITA. 
In his video if he moves the unit it goes off and then on. 
At least that is an easy upgrade :P

dcibel

The wallwart is just a basic switching 12V supply, worth about $5. I don't have problems with the connection being loose or anything, but I found a 2A 12V supply from an external hard drive in my parts bin that I'm using which has the correct length.

If you really want to go all out, iFi makes some "audiophile" low noise wall warts for about USD$50, effectively doubling the cost of this DAC