[wushuliu]

I may flesh out this post later, but anyone with a coax input DAC needs to check this out, like NOW:

F-1 XMOS USB Digital Interface Module XU208 U8 upgraded version - $180

http://www.ebay.com/itm/F-1-XMOS-USB-Digital-Interface-Module-XU208-U8-upgraded-version-/111961717820?hash=item1a11703c3c:g:UI0AAOSwAvJXBdC1

It uses some brand new XMOS chip. This thing is no joke and is probably where the next wave of Dacs is headed. Not talking 'minor' improvements to sound quality but MAJOR improvement. $250 MyDac + $180 F1 = Wow. I'm not being hyperbolic. Heard about it on head-fi. People using it with $$$ Dacs there, but I play in the C&C end of the pool. Here is the writeup I just posted.
there:

Received the F1 today. Since I've been using an IDAC2 I was forced to buy another dac with coax to try out the F1. I used this as an opportunity to try out several from Amazon: the Micromega MyDac and the Peachtree DaciTx. Sorry, I have a very limited budget so no mega buck dacs to brag about. I also have a micro idsd arriving tomorrow since that has coax in - I love my IDAC2 and I will likely have micro replace it with the F1.
 
The F-1 is awesome! Granted I have been using strictly usb-based dacs for the past 4 years so I have never tried the Breezes or PUCs, etc etc. The last spdif converters I used were tenor-based. They did not sound this good. The F-1 is an absolute bargain for what it does. With only a few hours on it, music is clean and clear. No treble energy or edginess. The sonic presentation vs. usb w/ IP2 is no contest. The F-1 takes the dacs to another level and without changing the character of the dacs. The MyDac in particular has 3-D qualities and a midrange forward nature that shines with the F-1. With just the usb it was okay, not nearly as good as the IDAC2. Same with the DacIT.
 
These comparisons were done with just a diy coaxial cable (Audioquest all silver wire). I added the IP2 with the F-1 for a few minutes but for some reason that did not sound that great. Could be the IP2 needs to break in again since it's been unused for a while or synergy issues. I'll try again later.
 
With a limited budget for me any over $100 really has to perform to be worthwhile. USB regen stuff like the IP2 I've found to make small differences but not night and day. The F-1 is night and day. I will definitely spread the word. I admit I was *real* skeptical about rb's, er, enthusiasm but what can I say. This is a *must have* component.

[Letitroll98]

Great write up.  The specs don't say compatible with Windows 10, any idea if they have drivers for it?

[wushuliu]

Great write up.  The specs don't say compatible with Windows 10, any idea if they have drivers for it?

I have w10 and drivers work no problem...

[jtwrace]

Nice write up!     I'm curious to what you think of the Micro iDSD comparing USB and Coax with this F1?

[Atlplasma]

I'll have to check this out. I was considering a Gustard U12, which is highly rated, along with the SMSL X-USB XMOS. The SMSL is very affordable, but I haven't been able to find any reviews on how it performs.

[Atlplasma]

@wushuliu, are you using an external power supply or usb power? And are you doing anything else besides dropping the board in a case? Just curious what else is required to turn this board into a working converter.

[wushuliu]

@wushuliu, are you using an external power supply or usb power? And are you doing anything else besides dropping the board in a case? Just curious what else is required to turn this board into a working converter.

Hey Atl. Not using any external power supply, it powers off the usb. It's plug and play - haven't even put it in a case yet...

Don't know about the Gustard or SMSL personally. As I understand it, the F-1 uses a newer Xmos chip that provides superior performance. The feedback on head-fi seems to be it is better than the Gustard/SMSL/Breeze, etc. But this is still very new to market so reviews are still coming in.

[Tomy2Tone]

How many hours would you say you have on it? Any change in sound since you first popped it in?

I placed an order this morning after seeing this, I believe it was you wushuliu that turned me on to the hammond m choke and I tried taking them out once and quickly put them back. So you got a good track record with me...

[wushuliu]

Nice write up!     I'm curious to what you think of the Micro iDSD comparing USB and Coax with this F1?

I spent a little time this evening comparing inputs on the idsd micro. The micro puts up a good fight via usb - like the idac2, it is such a great sounding dac. My favorite budget dac. But I still think it sounds better with the F-1. The usb presentation is more lush, mellow, but flatter. Hate to use the 'v' word but it sounds veiled in comparison. Hazy. The F-1 provides greater depth and separation between instruments and vocals. It's a more 'neutral' presentation. Most of all the F-1 regardless of the dac I sampled sounded more real with a clean, digititis-free sound. It also helps level the playing field: the micro/idac2 sounds the best of the bunch via usb hands down imo. However, the Micromega sounds *excellent* with the F-1. The TAS gushing review makes more sense with the F-1. And it's only $250 now on Amazon. I'll have to A-B some more. May just keep it.

Anyway that's my take for now. Again what's great is that it's not a 'i think it sounds better'. It just does.

[wushuliu]

How many hours would you say you have on it? Any change in sound since you first popped it in?

I placed an order this morning after seeing this, I believe it was you wushuliu that turned me on to the hammond m choke and I tried taking them out once and quickly put them back. So you got a good track record with me...

Only got the F-1 yesterday evening so just a few hours. Supposedly 100 hours is needed before serious evaluation.

[wushuliu]

FYI, there is a cheaper boarding using this new xmos chip but with fewer features. Not as good as the F-1 apparently (still not much feedback), but very good all the same. Only $70. Not on ebay though.

http://www.aliexpress.com/item/Singxer-X-1-digital-interface-module-XU208-XMOS-USB-interface-U8-updated-version/32646893064.html?spm=2114.30010308.3.2.tVqpWC&ws_ab_test=searchweb201556_8,searchweb201602_2_10017_10034_10021_507_10022_10020_10018_10019,searchweb201603_7&btsid=32f2baef-f5fc-4393-9686-9ccd2a623e09

[Atlplasma]

There is an extensive discussion thread at http://www.head-fi.org/t/803111/xmos-xu208-usb-bridges-the-latest-gen-has-arrived/165. Discusses the F1, the X1, and something called the Q1.

[wushuliu]

There is an extensive discussion thread at http://www.head-fi.org/t/803111/xmos-xu208-usb-bridges-the-latest-gen-has-arrived/165. Discusses the F1, the X1, and something called the Q1.

Yeah, that's where I heard about the F-1. Kind of a manic thread, so readers beware.

[Ultralight]

Sorry for the very basic question  I'm still not clear.

Does this mean that I take the USB output of my laptop, and then it coverts to an OPTICAL output to be connected to any device that takes optical input?  If so, I've been shopping around for one.

Anyone compare this to Wyred4Sound uLink that converts from USB to Optical output?

Thanks!
UL

[Letitroll98]

No, it converts to a coax SPDIF output.

[wushuliu]

I've been using the F-1 and doing comparisons vs. usb with and without purifiers, intona, etc. The F-1 responds well to usb purifiers and there's probably room to improve yet. Even on its own though its core strengths remain. I think this device is a game changer. All these purifiers I've been playing with cost as much or more and although they help, they do not elevate performance in the way the F-1 does. I was trying to figure out how to describe in detail the change in presentation and I kept coming back to vinyl. Not even terms of resolution per se, but just the way your hearing processes what you hear (maybe the word for that is resolution). I found some feedback on the F-1 that sums it up pretty well:

But the most that surprised me was that I started to believe in the first time that digital music will soon be able to have a real battle with vinyl recordings. My teenage son walked by and thought the music was coming from my vinyl setup - that never happened before. The treble was clear so that I heard wider and deeper sound stage. The base was extended. In addition to the treble and base, the mid range (human voice, etc) were very good too. Altogether, it sounded well balanced and clean.

[/b]

When I say vinyl I don't necessarily mean $$$$ tables. I think that's where all the purifiers and power supply doodads come in. For instance I would say the F-1 by itself is like a solid basic direct drive – like the cheaper vintage technics. Once you start adding like the nano iusb 3.0, things start to open up and you get that expansive floating quality of a suspended table. I do miss my old Kyocera table… but the F-1 makes me think those pining days may be over. I am using it with <$500 dacs but others are using it with much more expensive gear (with varying effect), so it’s not just for the budget stuff.

FYI, the sudden demand is causing delays apparently so be prepared, shipping may take some time.

w

[Tomy2Tone]

Picked up the F-1 yesterday from DHL and tried it both at work on a pc and at home with a microRendu. Both cases it made a very nice improvement to the soundstage. Everything was cleaned up around the edges and there was better separation of voices and instruments. I would say it took the level of realism up a notch or two. Two thumbs up!

The ebay seller wushuliu provided the link for was very responsive to my questions and they felt bad for having such a delay in getting it out to me (apparently this thing is super popular right now) so they included a Yulong Audio CU2 usb cable in with the package. I wasn't familiar with the brand so I looked it up and it's an $80 cable that they threw in for free...

[wushuliu]

Picked up the F-1 yesterday from DHL and tried it both at work on a pc and at home with a microRendu. Both cases it made a very nice improvement to the soundstage. Everything was cleaned up around the edges and there was better separation of voices and instruments. I would say it took the level of realism up a notch or two. Two thumbs up!

The ebay seller wushuliu provided the link for was very responsive to my questions and they felt bad for having such a delay in getting it out to me (apparently this thing is super popular right now) so they included a Yulong Audio CU2 usb cable in with the package. I wasn't familiar with the brand so I looked it up and it's an $80 cable that they threw in for free...

 

[Tomy2Tone]

I was going to add I'm just using a cheap RCA adapter to connect to the dac. I don't remember the Audiophileo having this great of effect as the F-1 is doing





The F-1 is the first add on piece I've tried with the microRendu that actually makes a positive influence.  It's sounding pretty sweet right now...

[Russell Dawkins]

It seems that impedance mis-match with RCA connectors carrying S/PDIF digital signals is no longer a concern. Using cheap RCA adapters will cause reflections in the digital path. Impedance mis-matches creates a reflection, causing jitter as the signal reflects back and forth in the conductor between mis-matches. Trouble is, there are precious few true 75ohm RCA connectors out there—I'm aware of only one, made by Canare.   http://www.canare.com/UploadedDocuments/75%CE%A9RCAConnectors.pdf

I see the output impedance of the cheaper converter board shown here:
http://tinyurl.com/hj7f8t4
is 75Ω, as it should be (that's the standard) but much digital interconnect uses neither 75Ω cable nor proper 75Ω RCAs. For pro use, S/PDIF is sent down coaxial 75Ω cable with BNC connectors, especially when long runs are needed.