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There will be a hi-fi show in Penang 11-12 June 2022 which is only 3 weeks away. Luckily, with the completion of USB2 Isolator prototypes, we are ready to demonstrate AA Music Streamer with the isolator.

Just a few days before the weekend of Eid Mubarak festive holidays, the semi-assembled prototype PCBs (with 0402 capacitors assembled) arrived. We purchased only 4 units of Texas Instrument’s XISOUSB211 pre-production samples (limited to 2 pcs per order), hence at most only 4 prototype boards can be made. The hand-assembled boards were completed last week but the troubleshooting and testing were only completed this week.

There were issues with TI’s footprint used in PCB design – the pitch was 0.66 mm (incorrect) when it’s supposed to be 0.65mm. It can be clearly seen from the above picture that not all pads were aligned correctly to the chip. With careful placement and soldering, there were no bridging. The PCIe brackets custom-made by Gompf Brackets Inc, USA were reused from the previous USB filter.

Swiss-made Audio Consulting’s 24 AWG solid-core silver wire with cotton sleeving (for data lines) and USB2 4-way IDC connectors were used to connect motherboard’s internal USB2 header to the USB2 Isolator input (left side of above picture). A dedicated 5V isolated LPSU (with floating ground) feeds the peripheral side of the isolator. This 5V supply previously powers USB cards like JCAT USB XE and also the passive USB filter.

From the rear of Streacom FC10 case, the look is very similar to the previous USB filter. Connection to USB DAC is made through the PCIe bracket of USB2 Isolator, not motherboard’s USB2 ports.

I will not comment on how it sounds. Please come and visit our booth at Penang hi-fi show on 11-12 June at Ascott Hotel, Jalan Gurney, Penang. Formal announcement of the event is coming soon.

Please note that TI has not released the ISOUSB211 chip. The pre-production sample XISOUSB211 is no longer available for purchase. I hope it will be released to production soon so that we can start selling AA Music Streamer with the USB2 Isolator.

Please leave your comments here.

This is the first time I evaluate USB2 high-speed isolators. I have evaluated USB2 Redriver and USB regen/reclocker cards. USB2 Redriver has little improvement to SQ. USB regen/reclocker PCIe cards have its own sound signature and the 5V DC supply really matters.

Most USB isolators were designed for rugged industrial use, but it works for audio as well. The isolation voltage ranges between 1kV to 5kV. Budget USB isolators like Topping HS01 only provide Ground isolation unlike the industrial ones which provide isolation for ground, power and signal lines.

The original Intona USB Isolator from Germany in crude plastic case was designed for industrial use. One person tried it with USB Audio signal path and discovered it indeed improves the sound significantly. The news spread quickly. Intona has the newer versions in metal case which can even improve Taiko Audio SGM Extreme USB Audio output.

Why the need to isolate USB

In industrial use, USB isolation was meant to protect computers from dangerous voltages in rugged environment, for example, PC-based oscilloscope used in automotive. In audio use, it’s to isolate the noisy DC ground of the computer power supply. Some high-end DACs already have USB Ground galvanic isolation inside the USB receiver. From my experience, using industrial-grade USB isolator can improve the sound further even when the DAC has USB Ground galvanic isolation.

The Need for USB2 High-Speed Isolators

High-res music in PCM and DSD requires USB2 to operate in 480Mbps high speed mode. Most of the earlier USB2 isolators provided by chip makers like Analog Devices only work in USB2 low speed (1.5Mbps) and full speed (12Mbps) modes, hence they are not suitable for USB audio use. One of the integrated circuit (IC) for USB2 Isolation with support for high speed and used in many USB Isolation products (including Uptone ISO REGEN) was Silanna ICE08USB which was introduced in 2015 but discontinued in 2019.

In 2021 Texas Instruments (TI) announced their ISOUSB211 product to be available in Q3 2022. Analog Devices recently has the ADUM4165/4166 USB2 high-speed isolators available.

USB2 High-Speed Isolators available for purchase

The list here is not comprehensive but includes the popular products. Most of the earlier products based on Silanna ICE08USB are no longer available for brand new purchase, which include:

• Uptone ISO REGEN
• iFi Nano iGalvanic3.0
• Singxer UIP-1 USB Isolator

The following are the products we can buy as of March 2022:

• Intona 7054-series USB2 and 7055-series USB2/USB3 Isolators
• ALLDAQ ADQ-USB 3.0-ISO-PS / 3.0 Isolator incl. Power Supply
• Virtins Technology VT USB-ISO-480 USB High Speed Isolator (>800 mA, comes as USB dongle)
• Topping HS01 Ground Loop Isolator

Three of the companies listed above make industrial products. As mentioned earlier, Intona (Germany) makes USB2/3 Isolators for industrial use. ALLDAQ (Germany) and Virtins Technology (Singapore) are both PC-based measurement and instrumentation companies making products like oscilloscope.

Topping HS01

The HS01 only provides USB ground isolation. It only supports 480Mbps high speed. I have done quick listening test with another friend. My recommendation – DO NOT waste your money and time with this product.

TI’s ISOUSB211EVM

I bought two of these (only 1 unit allowed per order) since modifications need to be made. My first hand experience with the default settings – I was surprised by the improvement in layering, decays and details without being too digital. The sound is less congested. I prefer the sound when using TI’s ISOUSB211EVM compared to Core Audio USB P24 OCXO and JCAT USB XE cards.

EVM Modifications

Ideally the 5V from motherboard should not be used, but the default EVM configuration uses 5V from motherboard’s USB and isolated DC-DC converter to generate 5V to the DAC side. The default configuration also uses internal LDO to generate 3V3 from VBUS1 (input side) which is suboptimal. Changes made:

• Disconnect 5V from USB A connector
• Use external LDO to generate 3V3 on the input side
• Disable 5V LDO (input voltage from DC-DC isolated converter) on the output side
• Add terminal block for separate 5V inputs on input and output sides

2-rail 5V LPSU

I build my own 2-rail 5V LPSU so that each side of the board is powered independently. Here are some pictures. The encapsulated transformer is from Nuvotem Talema 80VA with dual 9VAC outputs.

The tests were done using evaluation board with makeshift setup like shown in the pictures above. Additional modifications were done by adding Vishay bypass capacitors at the 5V terminal blocks.

Another EVM board was purchased for comparison with the modified version. In its default configuration, the sound is totally different.

Intona 7055-C USB 3.0 SuperSpeed Isolator

Daniel Staemmler of Intona Technology could not confirm this will work my XMOS-based DAC, but he heard no complaints. Choosing 7055-B versus 7055-C was a tough decision since in What’s Best Forum, some Taiko Audio SGM Extreme owners prefer 7055-B (good for vocal) while 7055-C is said to be more suitable for orchestra and complex music. 7055-C has dual LT3045 regulators with lower noise measurements and supports up to 1A without using external power supply. 7055-B supports 0.5A only (single LT3045). There is Micro USB port if the connected USB device requires more current. In the end, I bought 7055-C and luckily it works well with my Marantz SA-10 used as USB DAC.

The Intona USB3 Isolator is indeed very small in size, easy to place behind DAC or music streamer. I prefer the sound when placed near the streamer. The USB2 port used is the one with separate 5V DC, called USB filter.

Analog Devices ADuM4166

A week after online order placed, I received Analog Devices EVAL-ADuM4166. Its operation requires 2 rails of 5V DC supplies, which I have already built. This board requires no modifications. The 5V DC terminal blocks are already on each side of the PCB. The jumpers were set to 5V at each side, with the 5V at peripheral side powering VBUS.

ADuM4166 was selected instead of ADuM4165 as the external 24 MHz crystal is on the peripheral side, hence more suitable for USB Audio. The design makes it possible to use higher quality 24 MHz crystal or clock. The only surprising fact about ADuM4165/ADuM4166 family is that they are not USB2.0 certified, but per my tests it works with USB Audio.

Preliminary Listening Impression

With Intona 7055-C in my own system, the sound is very high resolution. Definitions and separations are very good. However, after long listening, it can be a bit fatiguing. The sound feels a bit unreal. With TI’s ISOUSB211, the sound is very musical but with slightly less resolution. Vocal sounds more realistic with TI’s ISOUSB211 and layering is really good. More details unheard before can now be heard, most likely due to lower noise floor. AD’s ADuM4166 surprisingly degrades the sound compared to using my own USB filter.

I also had the chance to test the USB isolators with Dr Azmel’s system in Taiping. DACs include Chord Hugo TT2 and M-Scaler combination plus Matrix Audio X-Sabre 3, mainly used for DSD. The Chords were tested with AA Streamer using USB input from JCAT USB XE but the sound was not impressive as reported by Dr Azmel. With TI’s ISOUSB211, the sound from the Chord components is good. When X-Sabre 3 is used, the sound is more musical, less fatiguing, and better layering. With Intona 7055-C, the sound is high resolution with good definitions and separations but lacks musical soul, consistent with what I heard with my own system. We also tested AA Streamer JCAT USB XE output into Denafrips GAIA then its I2S output into X-Sabre 3. We heard colored sound and we both do not like it.

Next Steps

The plan is to develop stand-alone USB2 Isolator based on TI’s ISOUSB211. It will include the required low-noise linear PSU to power each side of the USB2 Isolator and power the USB VBUS (DAC side) independently. Stay tuned.

Please leave comments here.

With his permission, I am copying the contents of fb group post (Hifi Talk Malaysia, private group, only members can view) by Mohd Firdaus bin Ishak into this blog.

Firdaus is already using a powerful Intel NUC as semi-DIY music streamer with Windows 10 and JPLAY FEMTO, so I thought this is a good avenue for comparison. Firdaus also took the time sharing his experience, including capturing and uploading videos to YouTube (links available here).

First post – The AA Music Streamer

(created Feb 6 2022, content copied Feb 21 2022) Original fb post

this was supposed to be quick and simple write up of my thought but after finish i found it quite ( very ) long.. so for those only interested of my finding can straight go to line 106.. like if you feel diligent enough to actually count..
there is nothing new about this soon to be release local made streamer by Dr Anwar Ali Mohamed . there are 2 reviewer had review this streamer as far as i know.
im not here to put another review.. don’t have such skill with fancy word to put up.. plus my hifi system is just so-so.. i just want to share my personal thought and experience with this streamer..
thanks to Dr Anwar loaning this unit to me for a field test..
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[ my setup before this PC streamer ]
before i put my thought on this streamer, maybe let me brief a bit of my previous experience on digital music player that i had on the past.. this will help you to judge my judgment 😅
i start my journey of digital music player with my first reference player, an android box ( nvidia shield ) connect to my DAC via USB.. why android box? because since i already owned it and not willing to spend for anything more.. i use Hiby music app.. it capable to play hires local flac and the sound is good enough for me..
then i discover there is music app called USB Audio Player Pro (UAPP). its not so expensive.. about RM50 including MQA addon.. maybe less.. This player stand apart from other player because it use custom developed USB audio driver for USB DACs bypassing all audio limits of default Android driver that most other music app used.. with UAPP i got better cleaner music experience..
then i was introduced to raspberry pi by Mr Ken Steel.. he poisoned me by loaning his Pi4.. its a small single-board computer.. there is many OS for audio that i try.. volumio.. roopiexl.. moode.. out of the 3 my favorite was volumio.. it has best sound and interface out of all.. this was my 3rd reference player replacing UAPP on Android..
after that i moved Volumio from pi to PC after i found upgrading my intel NUC skull canyon stock power supply to Linear Power Supply gave me much cleaner and quieter background.. i stuck with volumio for a while because at the moment i believed linux base OS like volumio best for audio player because it was a trim down version of full linux distribution made specifically for audio.. so nothing fancy running busy at background that may lead to noisy output sound..
NUC running volumio has been my 4th reference player replacing pi4 for quite a while.. until i came across Dr Anwar blog about Hysolid.. i do have a doubt if it can be any good since it run on windows 10 OS.. this in my understanding will have many unwanted process running and can caused interruption on audio output.. but since the fact that Hysolid is a background service thing that run only on background and no windows login required then this made me wanna give a shot.. i get some other m.2 ssd to install win10 just to try with Hysolid.. the result is really jaw dropping.. NUC runnning Hysolid was officially 5th reference player that time replacing volumio..
Hysolid is very good sounding Free music player. however the developer is no longer supporting the program.. so any issue will left abandoned.. even the app is kind of buggy.. music collection cant be too large else app will crash.. user interface need a lot of improvement and bug fix.. latest android cant run Hysolid at all.. need older android version.. This make me look for something else.. as suggested by Dr Anwar from his journey, i went for JPlay Femto..
I did not try JPlay Femto first before Hysolid because I dont like the retail price.. for me its too much for music player.. its 149.. not MYR.. but Euro.. about RM700… gila ah.. just for a program.. not hardware.. tapi roon lagi mahal.. USD12.99 per month.. lifetime for USD699.99..
But since it does come with 21 days trial so i just give a shot.. to be honest.. the sound quality isn’t that much better than Hysolid.. slightly better only.. but since by far Jplay Femto is the best sonic sound that i heard personally and Hysolid is buggy and no longer supported, after 21days plus 14 days extended trial, i made my mind.. i made craziest decision ever by paying for JPlay Femto.. i feel that its not really worth it.. but whenever i try something else for fun like Audirvana or Roon or Jriver along the way i always found Jplay Femto has better sound of my taste.. then i feel relieved😛.. at that moment.. NUC run JPlay Femto become my 6th reference Music Streamer replacing NUC+Hysolid.. and this remain my reference streamer for the time being..
in between there is also some streamer that i try like JF MX-Pro.. even though it have good sound with great interface and convenience i still prefer best sounding from JPlay.. or maybe sebab dah bayar mahal.. bagi sedap hati😛
i never experienced Music Streamer from manufacturer like Innuous or Lumin or Auralic etc.. i love to try but too much investment just to try for fun.. gut saying it maybe better but not by far.. this is how i calm myself down avoiding reckless purchase.. it works so far..
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[ The Streamer Configuration and the Sound ]
ok now you know where i came from.. so my judgment might not be on par with some other higher level setup and experience..
with the NUC+Jplay Femto setup.. i have been sticking around without upgrading or changing gear for quite awhile now.. i feel like what i have now already good enough.. maybe a DAC with DSD support would be nice.. but i listen on 44.1 the most.. so im good with SoulNote SD710 DAC.. for now.. other than that i feel like my so-so system produce the best sounding ever.. any minor issue like a little boomy sound for some track i blame my small room and the bad acoustic treatment.. i always assume that.. i even ordered proper room treatment stuff to see if will help.. but things got delayed maybe after CNY.. sometimes i just blame the digital copy of the flac.. poor ripping approach la.. bla bla bla..
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[ configuration ]
now with the AA Streamer..
the moment i plug in to my system.. configuration is flawless.. i just need to hook up 3 things.. power cable.. USB cable for the DAC/DDC and LAN cable.. thats all..
next step is just installing driver for my DAC/DDC and copy my music to the SSD.. all this was done on my laptop connected on same network using remote desktop app build-in on WIN10.. or it also can be done using RD Client app from android or IOS device.. no hassle of monitor or keyboard or mouse on the streamer.. pure headless..
however.. there is a minor speedbump.. i did not manage to get JPlay detected on either of my bubbleupnp apps on android or mconnect on ios.. it took a while figuring out that my home network router need public access enabled for JPlay in firewall setting.. maybe because i setup 2 sub domain.. 1 special isolate for my hifi using mesh router and the other for the rest of user in the house using unifi router.. after enabling that in firewall setting my JPlay is up and running.. woohooo..
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[ The Sound ]
before i manage to figure out JPlay firewall issue.. i just able to enjoy the sound of the streamer from the windows.. so i login to the streamer on my phone using RD Client.. open chrome.. play some youtube song.. i search ‘audiophile’ on YT.. play the first video on the result list called ‘Audiophile Music Collection 2021 – Deep Bass and Vocals album – Audiophile NbR Music’
the NBR intro music is nice.. but yeah.. my NUC sound as nice either.. not surprise..
then the first track start.. the ‘St. James Infirmary’ i think.. huh.. the guitar pluck.. the vocal.. fills the room.. sound superb betol.. clarity very transparent.. half way i stop.. maybe never heard this track on my NUC that’s why i got overexcited.. or maybe its just a ‘new gear’ effect.. everything sound good at the beginning.. tak puas hati punya pasal.. right away.. i turn off the streamer and put on my NUC back.. login on win10 and play same YT track.. the intro.. lebih kurang.. as expected.. then that first track kick in.. sound as good.. but not as good as i heard moment before.. now i become picky already.. suddenly i feel like the NUC sound like having dust all around while the AA Streamer have cleaner sound.. hmmm.. its only a YT comparison.. dah tewas.. i was like “LEMAH..”
then i put on AA Streamer back.. after i manage to get JPlay Femto up.. i put some track on JPLAY Femto.. one from FourPlay.. i simply pick any.. that time ‘October Morning’ was chosen.. yep.. it does sound clean and very much pleasing.. again.. after the track finish.. i shut down and put back my NUC.. remember the boomy thingy i mention before? it present a little bit here on this track on my NUC.. noticeably improved on the AA streamer.. i was like.. ‘WHAT’.. it supposed to be fixed after i got my acoustic treatment arrived.. did i assume wrong? huhu..
then moved back to AA Streamer.. dah malas nak switch back and forth dah.. i have to accept the fact that my NUC have some weakness.. terima hakikat.. itu bukan lawan dia..
i kept on listening to few more track.. there is 6th or 7th album (cant recall which) from Focal JMlabs album has few electronic music.. i remember last time i hear the track it was not so enjoyable.. whenever the track play i always skip it.. maybe too much bass and feel drown.. but now i can enjoy each of them.. the electro bass punch sounds clean tight and under control.. so goood..
Listening to live album like Antonio Forcione and Nils Lofgren giving a big box room effect..
Decay and reverb effect make me feel like im listening in very quiet dark room.. like i was there kind of feeling..
worth to mention that my NUC connected to my DAC/DDC through JCAT USB Femto.. while the AA Streamer is using Dr Anwar’s own USB filter.. with the sonic sound that i get from AA Streamer im kind of having zero interest to take out the JCAT USB Femto card to try on AA Streamer.. like why i even need it.. it is actually against my natural behavior that always want to test every possible state 😅
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[ things i like about the streamer ]
-the LPSU-
The most valuable thing about this streamer is the power supply.. there is many LPSU available on the market including ATX LPSU.. but most of them either exotically expensive or lower quality component used can get from aliexpress or tabao.. judgement done just by looking at the low price assuming lower quality part used..
as for AA Streamer reading from the blog i can see pretty good quality part has been chosen.. some even custom made like the audio-grade toroidal transformer custom-made in Europe.. the LPSU also gone through few iteration mix and match component to get best desired sounding like TI and LT regulator to be used at output stage..
the 5v DC also has been improved from earlier design.. originally it already came with dedicated regulator output for each single rail before and not share but now to improve further each of the 5v line design with own dedicated rail.. meaning those rectifier, smoothing caps, regulators separate for each rail to have better noise reduction..
there is few other good stuff in there that im not really know well to comment like the vishay and kemet capacitor.. can check out the blog for more details..
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-the fanless case-
Streacom FC10 alpha was chosen to present the look of AA Streamer.. for me it was kind of overkill.. because the case isn’t cheap..
according to Dr Anwar the case is the most expensive part of the build.. also the case was specially design for PC heat dissipation.. but motherboard used in this streamer came with embedded CPU and CPU heatsink.. so it does not actually cooled by the FC10..
so what about the case that i like? the case was used to purely handle heat from LPSU and its done very good job.. temperature from the case is just light warm.. will took forever if you plan to heat coffee on that..
other than that the case is very solid and sturdy.. proudly present the Streamer..
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-USB Filter-
for me.. personally.. for now.. i think the streamer does very good job without expensive USB Card like JCAT USB Femto.. i will try if i feel to do so later.. yet if the streamer is still with me..
but for now even without it.. with it own USB filter, it does an excellent job lifting the sound quality of the streamer to higher level.. even the internal cabling for USB filter is pretty good.. pure silver core cable if not mistaken and dedicated separate power line..
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-headless setup-
with Win10 and JPLAY Femto, i like the fact that the Streamer is headless.. no monitor require to connect to the streamer.. no keyboard.. no mouse.. less potential noise ( acah2 purist ).. to use the streamer you just need to press the switch in front once and to turn off just press the same switch twice.. that’s it.. to login in the windows system for any reason like install driver or transfer music or debug anything just login from other PC or laptop using remote desktop program available in win10 or login using RD Client using Android or IOS device..
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[ wrap up ]
im honored to be able to try the unit on my system and overall, i like the Streamer very much.. it looks premium and the performance is outstanding.. big leap for some one like me with so-so system..
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[ my system used ]
Vienna Acoustic Mozart Grand Floor Stand Speaker
AVI S21 M1 Labs Series Integrated Amplifier
SoulNote SD710 DAC
Singxer SU1 DDC
Curious USB cable
Mike Lenehan Ribbontek Speaker Cable
Pair of Palic Diamond Silver Coax cable used as RCA cable
AFA Coax cable
Monster Powerline300 and Powerline400 power cable

Second post – [AA Audio USB Filter vs JCAT USB Femto] little story of Zinger Burger 😆

(created Feb 12 2022, content copied Feb 21 2022) Original fb post

As promised.. eventhough i have very low interest to try JCAT USB Femto on AA Streamer but since not every day one like me get a chance to play with high end streamer, so yeah lets do it..
To recap why i dont feel like trying the JCAT is because the sound of AA Streamer with its own design USB filter is superb out of the box.. like a complete package.. adding stuff to the chain i feel it gonna be like adding hot sauce in kfc zinger burger.. chef presented the way it is.. if the chef want hot souce in it it will come in the package.. betul tak? Like the P. Ramlee Burger.
anyway since i already own JCAT USB Femto so i thought why dont i just give a shot.. no harm trying anyway..
[ installing the card ]
So.. the Streacom FC10 alpha had the pci bracket placed horizontally for it form factor. Thus, it need pcie riser for this purpose.. will this degrade the sound quality? Nahhh.. purist will say everything affected sound but its a low speed so i have minimal to zero concern..
And since AA Streamer does have extra 5v DC rails so the JCAT can be powered internally through molex input on the JCAT.. No additional linear power supply required for this purpose.. however you can use external LPSU if you want.. just configure correct jumper and connect the 5v to 2.5mm DC input on the JCAT..
worth mentioning AA Streamer require long pci bracket for pcie card installation..
It does not require any driver installation on win10 as it use default microsoft renesas driver..
Siap.. ready to use..
[ the sound ]
So lets cut to the chase.. how does it sound? Can it be any better? Short answer is… surprisingly yes.. well it can be personal taste but since im sharing my experience so it gonna be based on my taste..
JCAT produce more sharp edge sounding.. can be a little bit analytical but within enjoyable range.. the USB filter however give more polite sounding.. some might prefer this.. softer edge with a trade of slight loose of saperation..
[ wrap up ]
So yeah.. thats my perspective of the 2 USB card.. JCAT win my heart.. but the USB filter is also excellent.. it is not something like ‘better than nothing’ stuff.. its a good good stuff.. if I don’t compare with the JCAT I already love the sound from USB filter out of the box.. the feel that i dont need anything else for the streamer.. a complete recipe streamer..
but probably this time its more like Heinz or Hellmanns rather than regular life’s hot sauces for the zinger.. an upgrade rather than alterations perhaps 😅
Maybe Dr Anwar Ali Mohamed can consider releasing this USB filter alone..

Please leave your comments here.

After getting additional feedback from two reviewers, the flagship streamer were tweaked and fine tuned which include a new 5V regulator board and all 6 rails on the main LPSU board populated.

The previous blog post on Nov 24 about product launch assumed Gelombang (A Festival of Sight and Sound) will happen in December 2021 and the plan was to launch the flagship streamer during the event in Kuala Lumpur. Gelombang was rescheduled to end-March 2022. The current Omicron situation makes it challenging to organize, participate, or attend any big events.

The flagship streamer will be ready for orders after a new website is created and goes live. This blog will be repurposed (no longer be about music streamer project) with selected contents moved to the new website.

Experience with Reviewers and their Feedback

One of my embarrassing experience making Windows 10-based music streamers work at reviewers systems is the need to allow streamer PC discoverability when connecting to a new network. It’s the way Windows work. It requires keyboard, mouse and monitor

If streamer PC discoverability is not allowed (the default if the prompt in the picture above is not responded with “Yes”), the tablet or phone apps (BubbleUPnP and Remote Desktop (RD) Client) will not be able to find and connect with the music streamer. It took me a bit of research and time to find the proper solution to make Windows automatically accept a new wired LAN network connection without compromising Windows security. This is a must-have feature since the streamer may connect to a different network switch or router, or maybe moved to another house. Since the connection is wired LAN in the house or showroom, not public WiFi, it only makes sense to automatically accept it.

Another question received from a reviewer (actually another person asked the reviewer this question) is on streamer’s ability to play CD directly since there is an option to put slim optical drive for ripping CD. This was tested. Windows Media Player (WMP) is one of the better options for playing CD since it comes with Windows 10. The fact that CD album artwork is automatically displayed is a nice WMP feature that VLC does not have. Controlling CD playback from RD Client needs edit of Group Policy setting for Removable Storage Access, otherwise the inserted audio CD cannot be seen from RD Client. Redirecting audio directly to remote PC can be easily done in RD Client setup before establishing connection.

While the CD playback audio quality with WMP is acceptable, the noise of spinning CD is annoying. Playing music directly from local SSD using JPLAY FEMTO remains the reference for sound quality (SQ). The slim optical drive should be used for ripping audio CDs, not for playback. WMP can be used for audio CD ripping.

New 5V Regulator Board

Since there is a spare unused 12V rail on the main LPSU board, it was used to generate super low-noise 5V dedicated for USB Audio with four levels of voltage regulation. In the pictures below, it is on the left side of the board, with LM1085 and LT1764A being the third and fourth-stage regulators respectively. Please note the use of Vishay MKP 1837 100nF Polypropylene Film Capacitors (3 black cubes) – these are expensive and hard-to-get, used as bypass capacitors with Kemet 22uF tantalum capacitors. The 3 secondary regulators (LM1086) on the right side are for SSDs rated at 1.5A each using Nichicon Gold output capacitors.

The main LPSU board is now fully populated. Originally, the spare 12V rail was meant to experiment motherboards with slightly more powerful CPU like Core i3 or i5 which need dedicated CPU 12V. Since the J5040-ITX is already sounding very good, the spare rail is now dedicated for USB Audio only.

USB Cards Evaluation

Two USB regen cards were purchased for evaluation:

• Core Audio USB P24 OCXO
• JCAT USB XE

Some may be wondering which USB card is better. I used the USB cards to improve the sound quality of my own USB Filter. The new super low-noise 5V improves USB Audio output significantly. My preference now is not to use any USB cards, just use the USB Filter.

USB regen card is a necessity if the music streamer PC uses standard PC SMPS. The worst use-case is when motherboard’s USB port connects to USB DAC, and if this is compared to USB regen card supplied by an external low-noise LPSU, the SQ difference will be day and night.

Adding USB card is almost like adding flavor to food. Each USB card has its own sound, and it sounds very hi-fi instead of musical. Since I use Marantz SA-10 SACD player as one of the devices to voice the music streamer, I always compare the sound from SA-10 versus the sound of streamer’s USB Audio Output into SA-10.

SA-10 is a very musical SACD/CD player. The musicality is lifelike, especially with musical instruments’ decays. Instruments sound real. With a dedicated rail of low-noise 5V supply for USB Audio Output, just using motherboard’s USB2 header into own-developed USB filter gives similar or slightly better sound compared to SA-10 playing SACDs/CDs, but with the convenience of remotely controlling playback from a tablet.

When the low-noise 5V is used to power USB regen card, the sound becomes hi-fi. Decays are shorter, sound feels finer and bass becomes too controlled and unreal. Real musical instruments do not sound that way. Some people may prefer hi-fi sound instead of musicality. For me, I want to listen to music, not hi-fi.

Between the 2 USB regen cards I tested, JCAT USB XE wins as the better hifi-sounding USB card. The USB P24 is too polite with poor bass control. However, there are some problems with JCAT USB XE – it runs too hot with its heatsink temperature in the high 50s C, approaching 60 C. Due to Streacom FC10 case design, the PCIe card needs to be mounted horizontal with the heatsink facing down. Part of the heat which is supposed to get out from the heatsink goes back to the PCB. Once the temperature goes too high after continuous use, the SQ is no longer good. The USB P24 does not have this heat problem – it sounds better after continuous use. Maybe the JCAT USB XE should be tested when plugged directly into the motherboard when a different case is used.

Updated Streamer Configurations

The updated LPSU design resulted in updated configurations for the streamers as given below.

Flagship Technical Specifications:

• Windows 10 21H2 IoT Enterprise LTSC OEM
• JPLAY FEMTO + BubbleUPnP on phone / tablet (phone / tablet not included)
• All-in-one music streamer solution without the need for external power supplies
• Best SQ with local music playback (stored in SSDs)
• Optional slim optical drive for ripping CDs
• Sounds good even without USB Audio regen/reclock card

Note: Linux option may be offered to customers who prefer convenience and not worry too much about sound quality. The use of Windows 10 resulted in very high SQ, but the users must be PC literate.

Entry-Level Technical Specifications:

• User-installed O/S + playback (e.g. Daphile, Euphony)
• For Linux-based O/S, music files can be stored into primary SSD
• Final computer case design is still pending

FAQ

• Is it possible to buy LPSU only? Yes, in the future
• What other motherboards have been tested with this LPSU? So far, only Pentium and Pentium Silver SoC mobos. We may offer LPSU with EPS 12V @10A for CPU in the future, with the other rails at 5A max.
• Why the entry-level model is not ready? Due to the use of cheaper computer case and more compact LPSU board, the sizing of proper heatsink is challenging and is not done yet.
• I already have JPLAY FEMTO license. Is it necessary to buy another license? Please contact JPLAY if you would like to transfer the existing license to another motherboard.
• I only do music streaming from internet without local storage playback. The AA flagship music streamer maybe overkill for your needs.
• I am not PC literate and not comfortable with Windows 10. What other options I have? Euphony is one of the better sounding Linux-based music player and is very easy to use but not cheap. You can also consider Daphile which is a free Linux-based music player.
• What is Windows 10 21H2 IoT Enterprise LTSC OEM? This is not the regular Windows 10 which consumers can purchase. Only system integrators can buy and deploy the license of Windows 10 21H2 IoT Enterprise LTSC OEM. It does not come with bloatware like regular Windows and sounds better compared to Windows 10 Pro. OEM license means it is tied to the motherboard and is not transferable.

If you have any comments or questions, please post it here or send private message.

The last post was about the updated LPSU board. A prototype unit of entry-level streamer was also built and briefly tested. 2 USB hub/regen cards were purchased to evaluate the SQ improvement with USB card. Windows 10 version 21H2 was launched. This post provides quick updates for each subject.

LPSU Tweaks

The updated LPSU board is gold plated, 3 oz. copper on both sides, and 2.1mm thick for better stiffness to support the weight of smoothing capacitors. It uses Texas Instruments’ LM1084 and LM1085 voltage regulators for first and second stage voltage regulations, providing maximum 5A per rail (only 5V standby is 3A rail). The 2 prototypes built earlier used TI’s LM1084 for first stage voltage regulation followed by Linear Technology’s LT1764A voltage regulators for second stage, providing 3A per rail. After serious listening and with the help from close friends who came and listened (thank you so much for your time and help), some tweaks were required to get the best sound quality. In other words, the voicing needs some improvement.

Luckily, the new LPSU board design has a daughter board for powering 5V devices such as SSD and USB card. This small board is only for second stage voltage regulation. Originally it uses LM1085 ad LM1086, but for powering USB power filter or USB card, it sounds a lot better when LT1764A is used. Hence, a new daughter board was designed and tested.

The use of 5A per rail improves dynamics and micro details compared to 3A per rail. With LT1764A used to power USB power filter or USB card, the streamer finally gets the voicing right.

The Arrival of JCAT USB XE

JCAT USB XE is considered the gold standard for USB hub / regen cards. Currently the card is still breaking in. It will be evaluated against Core Audio P24 OCXO purchased earlier. USB2 Redriver card is no longer being pursued. With the latest LPSU board, it sounds better without USB2 Redriver.

Both JCAT USB XE and Core Audio P24 OCXO were installed into the same FC10 case. The motherboard supports 1 PCIe x1 only, hence only 1 card can be used at a time. A PCIe riser was used (not shown in the above picture).

Windows 10 IoT Enterprise LTSC, version 21H2

Windows 10 version 21H2 was launch recently in Nov 2021. Windows 10 IoT Enterprise LTSC, version 21H2, provides significant SQ improvement compared to the previous versions of Windows 10 Enterprise LTSC and also the regular Windows 10. This will be the operating system used in the final product. The music streamer will ship with OEM licenses for Windows 10 IoT Enterprise LTSC and JPLAY FEMTO.

If you already have JPLAY FEMTO license, there is no need to purchase the license again. Please ask JPLAY support to transfer the license to a new motherboard.

Launch Date

The music streamer based on Streacom FC10 case is ready for in-house demo. Even without USB card, it is already at high performance level. For those with high-end and highly resolving hi-fi systems, it is recommended to use USB card since it elevates the performance to different level. JCAT FEMTO XE will be offered at special price if this music streamer is purchased directly from me. In-house demonstration is available in Klang Valley area. Please contact me if you would like to have a demonstration.

Entry-Level Streamer

The first unit of entry-level streamer was build using Fractal Design Note 202 computer case. All parts can fit it. However, the heatsink used was too small and unable to deal with voltage regulators heat management. It runs pretty hot and becomes unstable if the cover is in place. Performance wise, it sounds better than Innous Zenith Mk2 updated to the latest Innuos Sense 2.08, even when using ASRock motherboard’s USB2 port. The heat management needs some effort. Work on this is put on hold temporarily so that can focus 100% on preparation for product launch in December 2021.

Mohd Firdaus was kind enough to loan his JCAT FEMTO USB. He tested the prototype briefly but due to heat management issues, the recommendation was to stop evaluating the prototype. A better heatsink or maybe fan sink (due to space limitations) is required.

Please leave your comments here.