The true experimental tweak thread

[gstew]

I did expect a change for the better when I ordered the Voltcraft FPS-1134 to power my router. I have suspected for some time that the AC mains noises was a affecting the SQ of the router. However, the extent of it really blew my mind!

I am more and more convinced that the galvanic isolation of the AC mains are the the key to success. Actually, another thing that proved this fact to me today was that when removing my FMCs from my main system today actually improved SQ on my secondary system (which is not galvanicly isolated from AC mains yet). Why? Most likely since I now have two less battery chargers connected. Next up for my secondary system will probably be to order this to my secondary system https://www.elfa.se/sv/isolationstransformator-200-va-230-vac-115-2x-vac-block-tim-200/p/15614532, wired as a balanced isolation transformer and connected to my active speakers to ensure galvanicly isolation with DC blocking abillities. [emoji4]

 

Cornan,

 

I think I am confused... maybe you can clarify something for me.

 

AFAIK, the Voltcraft FPS-1134 is a typical linear lab PSU with a transformer, rectifier diodes, filter caps, and an adjustable regulator. Is that correct?

 

If so, isn't its galvanic isolation just the same as any other linear supply. It is not like Vinnie Rossi's battery or Ultracap supplies or Uptone's LPS-1 or the SOTm battery supplies where the power source connected to the load is NOT connected to the AC line, correct?

 

Or am I missing something?

 

TIA!

 

Greg in Mississippi

[gstew]

Hi Greg,

 

The Voltcraft is a tech style linear regulated lab psu (ie. Safety class 1) with a fine-tunes voltage range between 11-14V. It is ofcourse connected to AC mains but the DC output is galvanicly isolated from the AC mains input. I have measured between the AC ground pin and the DC negative pin (black) and got nothing (continue-mode), which means that the galvanic isolation is very good. I wouldn't know how it competes with Ultracapacitor supply, but the advantage for the Voltcraft is the price point and Amperage.

Would be very interesting how it compares to for example VR Mini4EVR.

All I know is that it made a huge difference for my router!

 

Any other linear PSU is not properly galvanicly isolated AFAIK. Just the very good ones.

 

That last sentence seems to be an overly broad generalization, IMHO.

 

The only thing special on this linear is that the output is not connected to the AC ground. Which is common, but not universal. The galvanic isolation comes from the power transformer AND the lack of a connection from the outputs to the AC ground. I don't know how common or uncommon this is in lab supplies, but I've seen this in many DIY supplies.... virtually all of my DIY linear supplies are of this configuration.

 

Because it DOES have a galvanic CONNECTION to the AC line via the power transformer, it would not compare to the isolated output devices such as the VR Mini4EVR and his previous battery supplies, the Uptone LPS-1, and other devices where the output power source is not connected to the AC at all, including just powering a device from a battery. These devices break an inherent leakage path connection inherent in any AC-connected supply. AND while this provides them with explicit, specific benefits, it is not the only thing important in a supply... see Romaz's comments comparing his AC-connected Paul Hynes supply to an LPS-1.

 

I'm not saying that this is a bad supply or that what it does is not important or significant. I AM saying that I don't see anything special about it... on the contrary, in my experience, lab supplies are designed to be a safe, dependable, hard-to-damage source of DC, not audio-grade supplies. The parts they use are specified for these purposes, not necessarily for good audio quality. For example, all the lab supplies I've looked at have regulators not dissemilar from the ubiquitous LM317... fairly stable, hard to break, but barely acceptable performance for analog circuits and inadequate performance for digital circuits. Compare that to the LPS-1's TPS7A4700s, the Mini4EVR descrete regulators (I believe a Belleson variant), or Paul Hynes almost incomparible regulators.

 

I get that it makes a significant difference in the situations you've used it... and over most SMPS adapters, it should. But I'd be cautious labelling it as anything special.

 

Greg in Mississippi

 

P.S. When I say the Voltcraft is nothing special in the realm of galvanic isolation, the Linear Regulated DC Power Adapters I get from Jameco for $10-$20 when I'm lazy and don't want to build up a good linear supply (or for a situation where I don't need a good supply) have exactly that same characteristic.

[gstew]

I have not said that it would compare to a LPS-1 or Paul Haynes psu. I would assume they are better. Voltcraft is a huge difference to the supplied SMPS. Sorry, but I have not implied anything else. Would still be interesting to compare it to a audiophile supply though, since I do think that the galvanic isolation is very important for the router. I would'nt expect the linear regulators to be anything special on the Voltcraft either, but that is not the point. The point is that it made a great improvement over SMPS for pocket money. Anyone can afford it!

 

AND sorry too, I'm probably oversensitive... there was this other guy calling a uRendu a USB filter a few weeks back, got my hackles up. Understanding how things work (and I know I really know very little) is key to making things work.

 

My own experience is that linear supplies can work VERY well replacing garden-variety/consumer level SMPSs, we are in total agreement there. I know there are audio-quality SMPSs, heck the amps I'm currently using in both of my systems have them. And a lot of people like the iFi units and prefer them to some linear supplies. AND there's the Berning line of tube products, producing great sound with SMPSs since at least the mid-80s. SO they are out there.

 

AND thanks for the jog, at some point I'll try an LPS-1 on the network switches I use, though using an LPS-1 to power one of the FMCs I use in my systems was good, but not much better than a cellphone charger battery. I currently power those switches with what I'd consider a base-level audio-grade linear supply, maybe the LPS-1 will be a revelation.

 

Later!

 

Greg in Mississippi

[gstew]

On 1/13/2018 at 7:11 AM, Cornan said:

So today I got some time alone and started with one of my Stammheim 3A single ps LT3045s. First up I made the DIY Canare starquad cables, plugged it in, fine-adjusted the output voltage and let it run for 10 minutes to ensure a stabile voltage.

 

 

Next up was to connect it all inside the cubborn. Not easy, but it will hopefully be easier when I have moved to my new apartment, which is pretty soon now.

 

 

Just to be sure I monitored the current draw of Brooklyn DAC. It never even past 1A. It is always around 911-915 mA in my setup, so I could possibly even use my 12v/1A board if I wanted to. Anyway, maybe a bit too close to be totally safe? 3A is in any case very very safe! ?

 

 

 

I started to listen through my new Gibson Les Paul 8 speakers which is now a definate keeper. In the beginning of the first track "Carry You" by Novo Amor I got chills all over and almost could'nt keep my eyes dry. Almost like falling in love. Sooooo beautiful! ?

Everything sounded so complete that I was totally trapped inside the music. A lovely feeling that unfortunately doesn't come sneaking in that often! ?

 

 

http://tidal.com/album/71241182

 

The Gibson speakers really translate the music great with a very broad register from top to bottom without feeling perticular or tense about it. I can pull the volume very high before feeling the need to lower the volume. 

The single ps made this volume range even greater. Novo Amor is sitting in my lap singing kind of feeling. Pitch black background, dynamic and deep LF, refinded and very nicely sculptured HF and most of all a very natural "woody" presentation.

 

Stammheim have clearly made a brilliant ps! I am so so happy that I pulled the plug. Do I want to go back to Brooklyns DACs internal SMPS yet again? NO WAY! I found my preferred PSU. Sorry, I am not going after SR4 or sPS-500 either after hearing how beautiful this combo sounds. I am happily trapped inside the music now! ?

 

 

@Cornan,

 

Sounds like you got a winner too!

 

I mentioned earlier that mine has been improving with some run-in time. What I'm hearing now versus when I first started using them is increased detailing and dynamics, especially in the upper-bass through midranges, along with a slight increase in overall 'sweetness'. I'm listening closely daily to determine if it is really break-in or just the effects of our local weather, which has resulted in another round of WAY-below-typical temperature for this time of year.

 

 

 

3 hours ago, Cornan said:

 

I have'nt done it myself, but I think @gstew, @hurka and maybe @mozes might have tried it? Hopefully one of these helpful guys can chime in! ?

 

I have. See quoted post below on that.

 

I find the best way to use the LPS-1s (I have 10 around here now!) is to think of them as VERY good low-noise voltage sources that almost eliminate any issues from the AC source powering them (and with the JSGT or using a linear PS to energize them as I do, completely eliminates them). How they work best depends on what they are powering. In my upstairs system, I have 4 LPS-1s in an RPi HAT DAC digital source setup powering:

 

1. An Allo.com isolator board

2. An Allo.com Kali I2S reclocker board

3. The digital side of a Dial RPi DAC's DAC chip (my own hot-rod build) 

4. The analog side of a Dial RPi DAC's DAC chip

 

All of these have very good regulators locally... LT3042 on the Allo.com boards, ADM715x on the Hot Rod Dial DAC. I have tried additional regulators after the LPS-1s here (ADM715x or Belleson) and found they work best direct.

 

BUT I also use a couple of LPS-1s to power an SDTrans384 SD Card Player in my downstairs system. While it has ok on-board regulation (mostly ADP151s), it responds well to the best power one can feed it. At one point, I saw posts of some audiophiles in Japan using a set of solar cells energized by bright lights to provide the power needed by the board.. over the top, even for me!

 

On this board, I have used a dual 4||LT3042 and the dual 3||LT3045 version of the board that Cornan is using worked very well... the post just below includes the different options I tried getting to that choice and the last post shows some pix of my boards.

 

I energize each side with its own LPS-1, so I have 2.2A max going into the regulator boards and with the dual 3||LT3045 board which has a 3A max capacity, the full 2.2A is available.

 

Greg in Mississippi

 

On 1/12/2017 at 3:59 PM, gstew said:

 

I have run LPS-1s with 3 supplies so far... the stock Meanwell, a cheapo 12v supply, and a DIY 12v supply. I could not tell a difference in the sound of the gear powered by the LPS-1s with any of the energizing supplies. I DID have some noise bleed-through with the Meanwell, discussing it with Alex we suspect it was radiated noise picked up through my transformer volume controls. But it only happened in certain configurations while not playing and when setup for playing, no noise and no difference.

 

I'm currently building two pretty massive DIY supplies designed to each power up to 4 LPS-1s... I have plans....

 

 

 

 

While my current amps DO have SMPSs, I do not use any other SMPSs with my audio gear, including source computers and networking gear. And where I have changed SMPSs out for DIY'd linear supplies, when they are directly powering a piece of gear, I have generally heard improvements. I do have a friend swearing his R-Pi-based player using a modified HiFiBerry DAC+ Pro sounds better with a specific SMPS powering the Pi, I'll be trying that in my setup soon.

 

But I'm with Barrows and YashN and generally keep generic consumer SMPSs out of my setups.

 

 

 

 

I did an interesting test a few days back. I powered an SDTrans384 feeding a somewhat modified Soekris DAM DAC with the following:

 

1. A DIY linear supply based on the K&K Audio Low Voltage Supply here: http://www.kandkaudio.com/other-kits/ . It was the 12 watt version with larger caps before and after the regulator.

 

2. A single LPS-1 set to 5v

 

3. A single LPS-1 set to 7v feeding a Belleson 5V/2A regulator.

 

4. 2 LPS-1s set to 5v in parallel.

 

#1 was good all around, but did not beat any of the other options in any parameter.

 

#2 was the cleanest and most focused and detailed, but not as dynamic as any of the others. That doesn't mean it is not dynamic, just not as much as the others in direct comparison.

 

#3 was about as dynamic as #1 & #4. Also it was more focused and detailed than #1, but not as good as #2 or #4

 

#4 was more focused and detailed than any of the others EXCEPT #2, where it lost out a bit, though decisively. It was up in the same realm of dynamics as #1 & #3.

 

I stuck with the single LPS-1, #2, as my preferred power source for this, my best digital source.

 

My next try will be a dual paralleled LT3042 regulator board from OPC on DIYAudio, powered by 2 LPS-1s set to 7V, and paralleled at the output of the two paralleled LT3042 sections (each has 4 of the regs giving about a 1A output capacity). I'm hoping this will give me the benefits of the additional current capacity of 2 LPS-1s while retaining the detail and focus I get with a single one direct.

 

 

 

 

See this post from Alex where he described a quick and dirty series adapter:

 

http://www.computeraudiophile.com/f27-uptone-audio-sponsored/ultracap%99-linear-power-supply-1-operation-and-pre-purchase-thread-30173/index5.html#post615780

 

While I haven't done this myself, I did make up a quick DIY adapter for a friend who used it with two LPS-1s in series to power his Aries Mini to good effect:

 

http://www.computeraudiophile.com/f22-networking-networked-audio-and-streaming/overall-isolation-network-universal-serial-bus-industry-standard-cables-connectors-and-communications-protocols-between-computers-and-electronic-devices-and-power-29916/index21.html#post618874

 

Greg in Mississippi

 

 

On 1/13/2018 at 10:44 AM, gstew said:

Cornan,

 

Very welcome. Very curious on how Michael's regs work for you. Do remember they take some time to break-in... my experience is that circuits with ceramic caps take about 3 weeks of constant running to finally settle. I have one of Michael's dual-boards powering my SDTrans384 SD Card player. Its been running about 2 1/2 weeks now and starting to sound good... at 1/2 week I put the previous supply (a dual 4||LT3042 board from DIYAudio poster OPC) back in and slightly preferred that. Now I suspect it'd be the other way around (though not by a huge difference... both the LT3042 and LT3045 are great regulators. BUT the in-line ballast resistance of the LT3045 setup is 1/2 of that on the LT3042 setup, so a little less reduction in the 'goodness' of the regulators when paralleled). I power both of these with 2 LPS-1s with each powering 1 side of the dual board. 

 

I only have Michael's dual boards... he didn't have the 6||LT3045 boards when I ordered them. BUT for low-level digital electronics, the 2 LPS-1s into a dual paralleled LT304x regulator board is the best I've tried. One would need current-matched LPS-1s to do that into the 6||LT3045.

 

Pix of my build attached. I used different caps than Michael's BOM... I wanted to use the same ones as on OPC's BOM for his boards as I knew they worked well in the setups where I've used them. I also added a couple at the output to make setups more like each other. AND I used fixed resistors instead of the adjustable pots... again to make the two different implementations more like each other so I can get a better feel for the basic differences between 2x4||LT3042 and the 2x3||LT305 boards.

 

Later!

 

Greg in Mississippi

 

P.S. I added a couple of pics of OPC's 2x4||LT3042 boards for comparison.

 

Then the other boards in the build picture are alternative  reg boards from OPC for powering ES9028/9038/9038 DACs' AVCC rails. Working on implementations of a couple of those. Gotta love building SMD boards!

 

 

[gstew]

Just now, Cornan said:

 

Thanks Greg! 

<SNIP>

Interesting! Japanese audiophiles are really my idols in this hobby. I like over-the-counter ideas and might just give this one a thought as well! ?

Cornan,

 

See the main SDTran384 thread on DIYAudio for the solar cell power posts:

 

http://www.diyaudio.com/forums/digital-source/142562-microsd-memory-card-transport-project-post3569285.html

 

SOMEDAY I'd like to add some solar panels to our house with the main purpose being to provide power to critical things like the refrigerator during the occasional power outages... and the rest of the time, use them to power my audio setups. We'll see if I ever find the funds to make that happen!

 

Later!

 

Greg in Mississippi

 

 

[gstew]

1 hour ago, tapatrick said:

Me too ? I’ve been reading about SD card transports for the last few months and have ordered a SDtrans384 but could be some time as it needs min 10 orders.. 

 

Im considering a Rpi and an ALLO Kali reclocker to test out pure I2S into my PS Audio Junior. Very cheap  components and could be fun. @gstew

how do you rate the Raspberries with Allo reclocker as an I2S source?

Good for you, tapatrick. I'm considering getting a 2nd, always good to have a spare when one starts modifying one's reference source! So maybe we'll get to that 10 1 sooner!

 

AND it does native PS Audio-compliant I2S-over-HDMI! Power it up, plug in a cable, insert an SD Card, and GO!

 

I use various RPi setups as one of my main alternate digital sources, with various RPi DAC Hats (with good power one can get very good results from the best of them) and also one of my Soekris DAM1021 DACs. 

 

I get the best results from those when setup with a low-power music server (music on a 512Gb SD Card), good network gear, all linear power supplies on the music server, networking gear and RPi, multiple LPS-1s powering the DAC and interface cards, and using both a Kali & an Isolator board. I slightly prefer Allo.com's isolator to Ian's, but both are good. AND I suspect Ian's reclocker setup with good clocks will beat the Kali, but is more expensive and takes more power supplies.  The Kali II that Allo is working on should be better, but I still think the best setup will still be Ian's full FIFO setup with the isolation after the FIFO and just before the re-clocking output board. 

 

At that level, it is to my ears roughly equivalent to my SDTrans384 with a good, but now the best power supply. At some point I need to try the RPi powered by my now-reference source power setup, 2 LPS-1's into a Dual 3||LT3045 board. I did that once with the Dual 4||LT3042 board awhile back and it did lift the RPi a bit further. That might lift it close to the SDTrans384 with my reference power setup. Then there's always modifying the RPi to eliminate the on-board switching DC-DC converter and feed it good 3.3v & 1.8V... that would take it even higher. Also on my list to try.

 

But do get that the entire stream from music server on affects the sound in this type of setup. AND while mine is good, I know of a lot of optimizations and mods I could do to further improve it (and there's NEVER enough time!). Will those get the RPi to the same level as an SDTrans384? Dunno, I doubt it, but I bet it can get really close. AND the RPi setup has the benefit of easy access to one's library. BTW, I've been using the Logitech LMS server setup and PiCorePlayer with Squeezelite. Likely not the super-best setup, but good and easy to implement.

 

Your question reminds me I need to post some info on getting the best sound out of RPi setups. Likely blog it here, but after I get my current DAC projects running.

 

On using an RPi->Isolator->Kali into your PS Audio Junior, the issue you'll run up against is getting the raw I2S out of the Kali into the I2S-over-HDMI format for input into the Directstream DAC. K&K audio used to carry some boards designed to do that... I'd check there first. I also believe you can wire up a Twisted Pear Audio Teleporter  module... it's just a matter of getting a good HDMI connector (or hard-wiring in one end of a good HDMI cable) and getting the wiring right, I believe the Teleporter output is otherwise equivalent to other LVDS setups. Research that first, though. Sonore used to have some info on their website on that for the original Rendu Signature... not sure if its still there, but Jesus can probably supply if not.

 

Later!

 

Greg in Mississippi

 

 

[gstew]

57 minutes ago, steklo said:

 

 

Seems like Alexey's "Mezzanine Power board for Raspberry Pi" is just tailored for that purpose:

 

http://www.ldovr.com/product-p/mpower.htm

 

Feeding it from Stammheim's PSU board with 6V should make a nice solution, shouldn't it?

Steklo,

 

Thanks for that find! Yup, that would be a fab solution. While still a pretty advanced DIY, this provides a great framework for that effort!!!!!!

 

I'll be ordering 1 or 2 presently.

 

Again, thanks!!!!

 

Greg in Mississippi

[gstew]

11 minutes ago, steklo said:

The question is if 1A @ 5V is enough when the  3.3V and 1.8V circuits of the Pi are fed each with 0.5A in parallel?

I have run RPi's from LPS-1s before, which are rated at 1.1A. My experience is that they will boot sometimes and sometimes not. My LPS's for powering RPi's are rated at 3A. They ALWAYS boot the RPi. Part of the reason I originally setup an OPC Dual 4||LT3042 to be powered from 2 LPS-1s (1 feeding each side and them both sides paralleled at the output) was to get around this AND provide the benefit of LT3042/3045 regulation to the RPi. This is currently my reference supply for an RPi setup, though I expect the Dual 3||LT3045 board from Stammheim that I'll currently using to power my SDTrans384 will supplant it once I try it on an RPi.

 

Based on my experiences with RPis, 1A max works some of the time. 1.5A max works most of the time. >2A max works all of the time.

 

BUT if Alexey is selling them that way, they likely will work ok most of the time, I'd guess.

 

Only way to confirm is ask him... or get one and try.

 

My 2 cents.

 

Greg in Mississippi

[gstew]

On 1/16/2018 at 12:31 PM, tapatrick said:

Awesome Greg! Thanks for the info, lots to digest... and consider.



Would the Audi-gd HDMI card work to get I2S out of Kali? I have it after my WavIO board into my PS Junior with a hard HDMI adapter so it’s close to the DAC input. Works good. 

Tapatrick,

Sorry, I just saw I forgot to answer this. Yes, it should work just fine for that. 

In addition to the Kali, consider an isolator card too. The combo work very well together & the sum is definitely greater. If you can only do one, the Kali is by far the right choice. But both together is better. 

BTW, I have 2 of Alexey's RPi power cards ordered. They neatly solve the packaging of a separately-powered RPi that I hadn't found time to grapple with yet.

Now to get my current DAC builds done before they arrive. 

Greg in Mississippi

[gstew]

17 hours ago, tapatrick said:

Cool, thanks Greg

I was just looking at the isolator board last night thinking that might be a good addition but it wasn't clear on the Allo site if/how it fits with the Kali.

 

Does it come before or after the Kali?

Will definitely add it now. I am researching which bits to get which I will do this week and will look at Alexy's power cards too. They look the biz..

 

I need to decide on whether I get a Sparky or a RPi. I noticed that the Sparky board has the ethernet separated from the USB where as on the RPi, the usb and ethernet are all on the same circuit which is one of the Raspberrys limitations and source of noise.

 

Do you have any thoughts on this or does the Kali and isolator deal with this anyway? 

Welcome @tapatrick

 

The isolator board goes between the Kali and the RPi. It separates the two into separate ground regimes. It doesn't deal with the USB/Ethernet I/O limitations of the RPi, only reduces noise transmitted to the attached audio cards (which means you still want as good of a powering source for your RPi to get the best sound  even with an isolator board).

 

While what it does is a good thing, common experience is that while isolation helps (no matter how it has been implemented, at least so far), it is not the magic bullet many expected. Upstream SW & HW changes are still audible. Also, having the isolation in a separate board before the Kali is not the best way to implement isolation... best is to have it integrated with the reclocking circuit so that the noisiest portion of the reclocking (the FPGA) is before the isolation and the only parts after are the clocks and reclocking flipflop chips. That's how Ian Canada's board does it, but with much more complexity and expense. Still, the best sound I've gotten from an RPi has ALWAYS included an isolator and a Kali.

 

On RPi versus Sparky, while I like what the Sparky does on the HW side, I have stuck with the RPi due to the multitude of distro, SW, and HW options available. The RPi has limitations, especially from a HW perspective... shared processing between the USB & Ethernet, the  poor and non-audio family clock, the inability to accept a master clock for audio signal generation, and the so-so power network. BUT the amount of distros, SW, and HW available for the Sparky is so limited in comparison. What makes the RPi work for me are:

 

- HW solutions from companies like Allo.com and LDOVR.com that are mitigating the RPi's power and I2S signal generation limitations.

 

 - Some great distro and SW options. I run PiCorePlayer. Not the smallest and most optimized, it is pretty good in these areas and allows some customization to trade-off functionality versus slim footprint. And to my ear, it sounds acceptably good. But there are a multitude of other options.

 

- Using the RPi in a manner to minimize the effects of the shared I/O. That means I only use Ethernet and have no USB devices attached.

 

- HW solutions that generate and feed the bitclock to the RPi along with appropriate drivers so it produces a cleaner and better I2S signal. Though I have to say so far my experience is that a reclocked I2S signal via a Kali sounds better, but a well-done bitclock-generated I2S out of an RPi sounds greatly improved compared to the stock RPi I2S output.

 

I've tried to entice several companies into developing an audiophile RPi, sorta like what a Sonore Rendu is to their Cubebox solution.  Do a board with the exact same functional HW as the RPi, (so it runs the same distros and SW) with the same mounting footprint and connectivity for attached boards (so the audio HW devices fit), but with good, quiet linear regulators (LT3045 & such), an optimized power distribution network, a good clock, and a good power input (and maybe takeoffs to power the different rails separately). Unlike the Sonore and SOTM (and now other) devices, as long as it is HW-compliant, no SW development and support is needed, greatly reducing the cost of the device to the manufacturer.

 

The resulting board would still have the shared I/O and non-audio family clock limitations of the RPi. And it would likely have to have a larger base footprint than the RPi, though by making it mount-footprint and connectivity-compatible with attached cards, a larger base footprint just means a different case. AND it would still require a bitclock feed to sound pretty good and a separate reclocker to sound its best (at least in my experience so far). BUT even with those limitations, it would be a far, far better sounding device than a stock RPi.

 

So far noone's bitten, but I'll keep at it.

 

I hope this all helps.

 

Greg in Mississippi

 

[gstew]

6 hours ago, tapatrick said:

Thank you Greg for the invaluable info and full reply! VERY much appreciated and really helps.

 

I've been looking into Ian's boards which is another interesting direction to go in. His products seem to be very well thought out and executed but also a bit complicated to get them. Too many choices now to pursue...:) Do you have any of his products?

 

I am drawn to his FIFO I2S isolator with the dual clock board, which would then have to go with the RPi. Needs further study to understand how the components and software will all fit together so I don't get it wrong.

 

Cheers Patrick

 

 

 

Patrick,

 

I'm glad that was useful.

 

The 2 DIY DAC builds I'm working on now will use an Ian FIFO stack each before the DAC. They will also be fed from RPis... I'll be trying them with / without Kali's & Isolators to see if they make a difference in this build. The DAC cards are Twisted Pear Buffalo-IIIPro cards, one using the ES9028 and the other the ES9038.

 

Before heading down this path, you want to consider how much of your source is native DSD. MOST RPi distro/SW setups (so far, AFAIK) don't do native DSD. Some will output DOP. Ian's Isolator board can be fitted with a DOP to DSD converter board. BUT I'm not sure many (or even any) RPi setups will playback native DSD. DON"T take what I say here as gospel, I'm not following this realm closely at this time as all of my source material is PCM. AND the FIFO II is also (again, AFAIK) a PCM-only device. 

 

AND if I have missed recent developments in RPi DSD, someone please bring me up to speed!!!

 

But if you, like me, have all PCM-based source files, read on.

 

Ian's FIFO II is a reclocker, in this setup the isolator is another board. To feed your Directstream Jr with the FIFO II via the AudioGD I2S to HDMI board, you want to get the FIFO II, a Dual XO Clock board, and the FIFO II Isolator board mini kit (and if you don't do SMD assembly, you'll need to find someone to assemble the Isolator board for you). This Isolator board (in this case) goes between the FIFO & Dual XO Clock board. Also the Dual XO Clock board can be had with or without clocks. You'll want to get it with clocks and use them to get the setup up an running. BUT the supplied clocks are not low-jitter units and only intended for testing the operation of the setup... after getting the setup running ok, you'll want to replace them with a pair of something like Crystek CCHD-957 clocks to really get the benefit of the FIFO Reclocking.

 

Finally, while I suspect you'll get a benefit using Ian's FIFO after an RPi to feed the AudioGD I2S to HDMI board and then feed that into your DirectStream Jr., I wonder if it will only be a fairly minor improvement over using an RPi/Allo Isolator/Kali stack. Since the Directstream already reclocks all input signals as part of the conversion to DSD AND does what appears to be a pretty good job of that, I'm not sure the improvement of the full-up Ian FIFO is worth it. Of course, I have not tried this and I could be entirely off base here. I have seen comments from those who''ve compared the 2 reclockers and found the full Ian FIFO an improvement over the Allo Isolator / Kali (of course, at a price). But those have all been in setups directly feeding DACs that do not have their own reclocking process AND did not have the I2S to HDMI between the outboard reclocker and the DAC. The process of converting the I2S to HDMI (actually LVDS over HDMI) and back adds jitter too, which to some extent will negate the benefit of the FIFO no matter which you choose.  What I'm wondering (and it IS pure speculation) is will the Directstream Jr.'s reclocking plus the added jitter of I2S to HDMI conversion mask the better I2S out of the full FIFO.

 

AND I need to be clear I don't have a personal dog in this hunt. I have units here from both Allo and Ian AND worked with them both in the past. I think they are both GREAT setups from 2 GREAT and INNOVATIVE sources that have raised digital DIY'ing to new heights. I can't recommend both setups enough!!! BUT I'm not sure Ian's FIFO will benefit your setup over the RPi / Isolator / Kali solution.

 

Sorry, another long one!

 

Greg in Mississippi

 

 

[gstew]

Patrick,

 

Very welcome. Glad to help... heck, your results will be VERY useful to me & my on-going projects, so it is DEFINITELY a 2-way street!

 

I spent some time looking at the thread on the PS Audio Forums (I mostly only look at the BHK Amp/Preamp and the AC Power forums there, as that's the PS gear I have currently. I'll have to keep tabs on this forum now too!). Looks like you've done some impressive DIY work! 

 

I'll be very curious how the Sparky/FIFO/Audio-GD HDMI module setup sounds compared to others you've tried. I'm not sure if the Sparky is much  of an improvement over the RPi if one is not using both the USB and Ethernet... Not sure if it is not either, I just haven't tried it. My gut feel is that if one is not invoking that RPi limitation, distro/software differences and configurations may be a larger factor than the device differences here.

 

One thing on Ian's FIFO... using the included clocks, I suspect it may not make much of a difference. Upgrading the clocks is what will give it a chance to improve on other options. In addition, there have been some discussions of process improvements at Crystek that have brought their lower-cost clocks to near-parity or better than their premium ones... do a search on CA for CCHD-575 and CCHD-957 to find those threads. It now sounds like the CCHD-575's at $12USD each may be nearly as good as the CCHD-950's at $25USD each and the CCHD-957's at $29USD each. The only issues with the CCHD-575's are the different package than the other 2 and they max out at 22/24 in audio clocks while the other 2 lines have 44/49's. With Ian's clock adapter boards, you should be able to fit any one of these choices. I'm looking at getting a pair of CCHD-575's to try against the older CCHD-957's I have here... and I'm also trying to find out if the CCHD-950's & CCHD-957's have also improved.

 

On improving the AudioGD I2S -> LVDS I2S over HDMI module, there's really not much there to work with. Both the sending and receiving sides use one of several standard single ICs that is designed to either convert single-ended I2S to the balanced LVDS format or back. There isn' t much else there except some bypass caps and signal line resistors and of couse the input/output connectors. BUT as with any digital circuitry, power is critical & should be as good as possible... I'd use one of the LT3045 add-on reg boards mounted directly on the power inputs to the board for best results. Short I2S lines are also crucial, even if you use the industry standard u.fl cables and connectors.

 

You probably have picked this up already, but any of these transforms (isolation or SE->LVDS and back) add some jitter to the I2S signals. That's why they work best in setups with a reclocking circuit afterwards, such as the Directstream DACs. 

 

BTW, if you want to try local reclocking of I2S lines where you have a good local clock, there are some somewhat scattered discussions of DIY I2S reclockers using flip-flops on TirNaHiFi... nothing that says 'this is how you do it', but as I remember, there are useful comments scattered in these threads:

 

http://www.tirnahifi.org/forum/viewtopic.php?f=15&t=3829

 

http://www.tirnahifi.org/forum/viewtopic.php?f=15&t=3750

 

http://www.tirnahifi.org/forum/viewtopic.php?f=15&t=3705

 

http://www.tirnahifi.org/forum/viewtopic.php?f=15&t=3232

 

If you want to get some inspiration on some gonzo DIY projects, also see these threads:

 

http://www.tirnahifi.org/forum/viewtopic.php?f=15&t=4002

 

http://www.tirnahifi.org/forum/viewtopic.php?f=15&t=4086

 

http://www.tirnahifi.org/forum/viewtopic.php?f=8&t=3810

 

http://www.tirnahifi.org/forum/viewtopic.php?f=8&t=4461

 

Later!

 

Greg in Mississippi

[gstew]

22 hours ago, tapatrick said:

@gstew Hi Greg

I finally received all the pieces and started to build my Sparky based Ethernet to I2S Roon streamer comprising the Sparky SBC > Ian's McFifo & McDualXO Isolator and rechecking boards > HDMI LDVS board > DAC.... I've got 2 replacement Crystek CCHD-957 clocks too but need some kind of carrier boards to help replace the stock ones that come with the McDualXO....more later when I get it all to work as its not simple or clear to me how to wire everything. I might well ask you for some help...:)

 

Just a quick comment... Ian sells a carrier board just for that purpose. I know he just launched a redesign of it too. 

 

As far as questions, let's exchange emails via PM to better keep in touch.

 

Greg in Mississippi