I was able to acquire another USB XMOS FUN01 modules (SU-1 Clone), with the exact same HW as my BlackGate™ module (aside from a few little changes). From the various XMOS and Amanero modules I’ve tried, the “FUN01” is my go to version for under $200 with CAT6 and AES/EBU outputs. This price does not include the power supply module and transformer that are seen with the real SU-1 by Singxer. The power hardware can be altered in various ways and still function. For example, you could go with a single wall wart with a 3.3Vdc to 5Vdc output and it will function, but I don’t recommend this.
I personally use a transformer with two 6 volt outputs/secondaries and I run one into a PSU module pictured below (soon) that gives me 2x 3.3Vdc out and one 5Vdc out. LA Nover, ELNA Silmic, and WIMA capacitors are all used on this module. I employ an EMI filter at the IEC (where wall plug cable meets unit) along with an inline fuse.
The elitist in the audio world may not like some of my HW choices. Such at those who after reading the model FUN01 XMOS, immediately dismiss any of my findings because they aren’t Singxer boards, however they are identical in almost every way. Also, since I do have two identical (clone) boards, the comparison remains valid for the capacitors, despite what you think about this sub $200 XMOS solution. I say this because the benefits and/or problems the FUN01 induces are equal on both boards and thus both sets of capacitors (our main subject here).
The Asian clone of the Singxer SU-1 model (FUN01), comes in around 1/4 of the price of the Singxer board (Note: The BlackGate™ module is the same FUN01 XMOS unit featured in my Burson Play review). This time I came up with a pretty good DIY way to create a removable socket for the capacitors. I used quality + correct sized terminal blocks (blue in pictures) along with some AMP socket pins/slugs, which are soldered directly to the capacitor leads.
One of the reasons I soldered directly to the leads is my ELNA SILMIC ARS Super Gold 100uF 50V have very short leads (came like this). These small cylinder/female-pins pieces, from AMP, made it possible to mount the capacitors into their terminal jack. Without using these lugs the capacitors weren’t able to even be mounted, a pretty good on the spot fix for my track record this year.
Now as you tighten the screw on the terminal block, the AMP pin’s cylinder collapses (where the capacitor leads aren’t at). In the end you have an excellent mechanical bond, along with being soldered directly to the capacitor terminals, an end-to-end solid signal path. I am sure you can improve on this idea further if needed. My modded XMOS unit fired up on the first try! Although, I had to re-solder a few of the AMP pieces to the capacitor leads, ad a solid connection is very important.
My hope is to be able to find and provide visual proof of what is different in the digital and analog outputs, depending on which set of capacitors are at play. Before the XMOS connects to another device, it has premium features built into it, such as full digital to analog isolation (you can clearly see the split ground plane, also called a moat, cutting the top ground screen to the end of the board). Most meaningful measurements take place after being converted back to analog, so the ES9038PRO will take on this duty. I definitely want to see what I can share from the Coax or I2S digital outputs for quality/accuracy comparisons, but the analog signals have the most well known measurements.
The ground plane cut is about 1/8″ wide and every signal goes through their respective dedicated digital isolators. You can see them bridging the cut plane, connecting analog and digital sides. This is how they are isolated and other equipment usually lacks such detail. This will add it’s own problems into the reproduction of this encoded digital signal. The best we can do is look at Coax and I2S for accuracy. Finally, we will have a proper oscilloscope article! I2S should be especially interesting with so many signals to check! In the hopes of increasing understanding I will also take a look at the analog side from the ES9038PRO.
I may have to build an ABY switch with relays to go between the two identical XMOS modules, aside from the capacitors of course. My first job is to find out how much a digital signal like I2S or Coax can be measured and compared for quality and accuracy. Also, how to best go about it, accurately, as well as easily reproducing it. I have some great sources, like “The Art of Digital Audio” and “Small Signal Audio Design” to name two.
100uF capacitors (with a min voltage rating of 25V) models used (so far) include: RubyCon BlackGate™ F, ELNA SILMIC ARS “Super Gold”, Nichicon Muse, Nichicon “Fine Gold”, Nichicon FW(M), ELNA Silmic-II, Rubycon RX30, BC Philips, vintage Sprague and a few others, I’m also looking for some really bad 100uF so that I might see a trend easier compared to high end modern capacitors. Being at the extreme opposites of the new to used spectrum and performance should be easier to distinguish. Then I can use this data to help me understand two capacitors close in quality, such as the BlackGate F and SILMIC Super Gold!
I have a full breakout board for CAT5/CAT6 with terminal and through hole available. This should make getting to the raw I2S almost as easy as coax, hopefully! I also have I2S switches, 2 of them, for connecting multiple devices for one output, usually handled by a mux. I could easily add both units for easy connectivity between units. Now I need to handle power going to both, one option is to just give both of them power, not a huge drain when not in use. Lastly is USB, we can’t have both units plugged up due to some quirks, so I need to make a DIY switch for USB or just disable one in Windows.
Initial thoughts on sound between “BlackGate™ F” and the pretty special, ELNA SILMIC ARS “Super Gold”
At first I noticed a volume drop when going from the BlackGates™ to the SILMIC-SG, but I also noticed that three of my capacitors needed to be re-soldered due to too much play in the terminal when tightened. After securing all capacitors that still had AMP lugs which you could remove, I reinstalled them and then the volume was exactly matched it seemed. This is a good simple test you can do during your progress
Remember to always check your component for possible size issues in your circuit and find smaller sized replacements if needed. I recommend Digikey personally, since you can use USPS up to like 3 ounces and only have to pay $2-3 roughly. It used to be 3-4x that, so they have stepped up their game. RadioShack was a sad store to lose, now no public business has anything like they had. Hardware stores have some, but very limited.
Note: A few things on the XMOS that will guide others and probably assist me down the road:
If you are playing a DSD track/album and you either hear no music or you hear hiss/noise instead, go to your DSP settings and disable everything. If that doesn’t fix it, then go to the DSD settings and make sure preferable area is set to none, setting it to stereo messes up a lot of albums for my gear.
You can get 352kHz PCM playback with the FUN01 XMOS, depending on the track format, there are two ways to do it. If the track is in 352 kHz, then you can just play it over ASIO and your DAC should report 352kHz sampling rate.