Building a DIY Music Server

[Superdad]

14 hours ago, Nenon said:

The clock is mounted on special vibration damping standoffs that decouple the clock from the switch board.

Those sound interesting and useful. Can you share a link?
 

14 hours ago, Nenon said:

The upgraded clock costs more than two etherREGENs. The power supply is another seven etherREGENs.

I’m flattered that you use the cost of an EtherREGEN as a comparative measurement quantity for your tweaks! 

[Superdad]

On 10/9/2020 at 11:15 AM, Exocer said:

This sounds interesting. It would be great if you could share some more details of the Connor Winfield clock you've used.

I would not bother with any of those C-W clocks you linked to.  Phase-performance of those is far worse than a good 

Crystek $10 XO.  
All you get with a $58 OCXO (besides a current-hog for the oven and a huge footprint) is a bit of frequency stability—something which matters not at all in the application.  To get decent low phase noise from an OCXO you either have to pay $350+ (and that’s at 200+ quantity) or scavenge particular clocks off of retiring 4G cell tower boards (that’s what the Chinese ham guy BG7TBL does; in fact the -125dBc/Hz at 10Hz offset 10MHz units he offers for $90 in a box are a steal).

[Superdad]

49 minutes ago, Exocer said:

I'm guessing Crystek or SiTime clocks are the only worthwhile replacements.

 

The SiTime MEMS oscillators do not offer very low phase-noise performance at all.  Even the SiT5711 favored by some (probably for its 3.3V input, small footprint, programmability, and fancy gold color) is only -109dBc/Hz (at 10Hz offset for 10MHz unit).

For comparison the $10 25MHz Crystek 575s we use are running about -108 to -112. Compensating for the 2.5 octave difference that -110dBc/Hz average equates to about -119 if that 25MHz Crystek was a 10MHz clock.

So why pay $150 for just unneeded long-term frequency stability. For these applications it does not matter at all if the frequency drifts a tiny bit over time!  

The ruggedness of the SiT5711 is something we will give it.  As a MEMS device it will perform better in a vibrational environment that most crystal-based clocks.  But still not low phase-noise...

 

49 minutes ago, Exocer said:

Aside from the Uber expensive PF clock, and CW clocks, options appear to be a bit slim.

 

Well what frequencies are you looking for?  There are (from Crystek, NDK, and a couple of others), some very low-phase noise XOs under $100. But finding stock for 24.0MHz and 25.0MHz is not easy (whereas the audio-related rates of 22.5792MHz and 24.576MHz and x2 those are readily available). But those will not get you into the -125dBc/Hz to -140dBc/Hz (@10Hz for a 10MHz) that a fine SC cut OCXO will.  But there you are looking at $375-$875 per piece...

And again, don't look to Connor Windfield for those (C-W is in the -90 to -100 range at best).

 

Spend some time at Dove and your head will spin: https://www.doveonline.com

 

Here is a nice clock:

https://www.taitien.com/wp-content/uploads/2016/01/XO-0136_NJ-10M-6800_series.pdf

-135 at 10Hz is a nice place to start!  But don't ask the price or lead time...

Or really go for it with one of these:

http://magicxtal.com/products/?S=20&C=36&I=82

-120 at 1Hz!, -144 at 10Hz.  Those are $1,200 each if you order five pieces...

 

49 minutes ago, Exocer said:

It would be nice to use the extra two outputs on my BG7TBL for something 😁.

Indeed.  But not without a really good programmable synthesizer to make the frequencies you want...

[Superdad]

1 hour ago, Nenon said:

I knew it looked very familiar and just realized why. I  opened my aliexpress account and realized I had those two chassis in my wishlist there :):

https://www.aliexpress.com/item/4000929646883.html

 

That is indeed the exact chassis. It is big!  Funny, because I bookmarked that one a couple years ago too.  Not keen on the face machining. But the price is quite good. And that's just single unit AliExpress pricing, not volume Alibaba wholesale!

I pay that much at 100 unit quantity for the much smaller (but finer finished) Takachi enclosure from Japan for our JS-2.

I'm sure that someday we will need a big chassis for a product, but there are plenty of reputable Chinese firms doing custom CNC. (e.g. http://www.yonggu-enclosure.com). It's in the finishing, Q.C., and shipping where one takes a real hit from China...

[Superdad]

40 minutes ago, ASRMichael said:

I suspect neither company designed it. They’ll be buying from a supplier & rebranding it. 

That's correct.  It is from Asia.  Not "bespoke" at all. Lots of similar products from Asia.

Yes, it is filled with cheap voltage regs and cheap clock.  

Also, the choice of using [multi-mode] single-fiber (Simplex) is odd as it adds a lot of circuitry to handle the multiple frequencies on the transceiver so that bi-directional signaling can take place.

 

Here is one that uses single-mode fiber:

https://www.transwan.com.cn/products/usb-3-0-2-0-1-1-over-fiber-extender-to-max-250-meters-mm-fiber-or-sm-fiber-with-10-gbps-sfp-module-supports-5-gbps-speed-backward-compatible-with-usb-2-0-1-1

And you can--via the drop-down, near Quantity, above AddToCart--that it to can be ordered for use with either single LC fiber or dual LC fiber.  Single really needed only if you are going to run miles and need to save cost of fiber. The transceivers are not as ideal for our purposes.

[Superdad]

2 hours ago, Exocer said:

Looking forward to the ISORegen successor (if there is one in the works!). Something with a reference clock input and really good onboard clocks would be great 😎

 

2 hours ago, elan120 said:

That would be great!  OptoRegen perhaps?

 

Thanks guys. We are advancing on several paths--with a couple very unique techniques/technologies--but the global ship shortages have made it very slow going. In fact, we probably have stock of about $40K in chips for new products--but just can't get the rest!  

EtherREGEN was a huge seller for us so right now we are near completely focused on the redesign of it so we can get back into production.  There will be one other, completely new product delivered this year--one that we know you will all love--but it won't be anything to do with USB. 

 

By the way, I have been enjoying the Monoprice SlimRun Optical USB (branded by them but actually a spin-off from a Taiwan chip company) between my streamer and DDC. But it uses DC-DC converters (at both ends) to send 12V (or did I measure 18V, can't recall) along with the fiber to the far end, I don't find using the 5V microUSB power port at the computer end has much effect.  

For several years there has existed a variation--using the same Taiwan translator chip--marketed by FIBBR (Yangtze Optical Fibre and Cable Joint Stock Limited Co., aka ‘YOFC’), called the Alpha USB.  It is bus-powered at the computer end and entirely externally powered at the downstream (DAC/DDC end)--oddly they don't include any 5V PS though you need one for it to operate.

Up to now the darn thing has been near-impossible to find/buy--and supposedly the full list price was $400. But today I managed to find it for sale, from a FIBBR set up sales web sire of all places--at just $199.  https://fibbrcable.com/products/alpha-usb-a-b-optical-fiber-digital-audio-cable

I could not resist so I ordered one. Hope it comes. And I'll let everyone know how it stacks up.

 

Now to be clear, like the Monoprice--and like all the other USB over fiber optic boxes discussed (including those using either SFP or internal transceivers)--this thing does not have anything special in the way of voltage regulators, good SMT caps, clocking, USB hub chips, or any such.  But it does share the same USB3>USB2 translator chip (a difficult to obtain, very poorly documented, one-of-a-kind part--which I happen to have bought 500 of last year on speculation, for one of the now back-burnered development projects).

 

 

[Superdad]

Since someone mentioned the AfterDark Nocturnes optical USB box set, and since I know a bit about all these various optical USB solutions at the chip level (see my prior posts, though I won't go into too much detail about the actual transceiver and translator chips used--there are only a couple of basic variants), I thought I would post about some experiments that I finally got around to today.

[With EtherREGEN and ISO REGEN, and UltraCaps all out of production, and JS-2 production running ahead--I have a lot more time these days while we wait for new board prototypes to come back. ]

 

As mentioned, the Audiowise OPTO/Lindy boxes are just private labels of an Asian piece and technically about the same as the offerings from https://www.transwan.com.cn

And then there are a bunch of 2-box SFP setups on AliExpress, which are based on this somewhat obscure USB2.0 extender/controller chip: 

http://www.wch-ic.com/products/CH317.html  But its usage is a bit cumbersome and not ideal since it must be paired with Ethernet RGMII>SGMII PHY transceiver chip.

Here is the box set that uses that technique:

https://www.aliexpress.com/item/1005002086574264.html?spm=a2g0o.productlist.0.0.4c071d55Z1kFJM&algo_pvid=9cc51ad5-3213-40d3-a0d7-29d1c49f0010&algo_expid=9cc51ad5-3213-40d3-a0d7-29d1c49f0010-3&btsid=0b0a555916223217208672489e55c8&ws_ab_test=searchweb0_0,searchweb201602_,searchweb201603_

The one I bought is exactly that but in black.

If you look closely at the jack layout of the AfterDark Nocturnes, you will see it is based on these same boards.  Only AfterDark added internally an OCXO--and I think they give you a 10MHz clock out. (Not sure how they do that since the USB board needs 25MHz and I am sure they are not using a clock synth to take 10MHz OCXO and make 25MHx; maybe it has two OCXOs.)

 

These CH317 chip based units, as well as the method used in the OPTO/Lindy and Transwan boxes is not as clean and simple as the translator chip used in Monoprice Slimrun and FIBBR Alpha USB (same as the now discontinued Adnaco/Everpro SU-1 which saw a lot of favor for a bit with Asian audiophiles).  And even though none of these devices are actually developed with power and clocking, flip-flop, and USB output techniques that ought to be used for best SQ, I think the simpler chip versions sound MUCH better (sorry I am avoiding naming the chip directly for several reasons; the curious can figure it out.; I have 500 of them that might find there way into a product someday...)

 

So here are some pics of my experiments today with the optical SFP box set I got from AliExpress:

 

The transmit side box on the bottom shelf is getting USB from my Pareto Audio (@lmitche) NUC that is running tweaked AudioLinux Roon Server & Bridge.

Then SFP/fiber to the receive box positioned with a UpTone USPCB Adapter right at the input of the heavily modified (thanks @scan80269!) Singxer SU-1, which in turn feeds I2S over HDMI cable (wow those cables can sound really different!) to an original Holo Spring Level 3.

All devices (including the EtherREGEN) are being powered by beta boards of a big new LPS we are working on (ignore that they are in UltraCap LPS-1.2 cases, it was just a convenient size for the beta boards; actual supply will with completely different, much larger, with Cree diodes, triple regulation, and special transformers).

 

Anyway, today's test was the Aliexpress optical box set versus the Monoprice Slimrun.  Long story short, the Monoprice is MUCH better in every way.

Looking forward to receiving the FIBBR Alpha Optical USB as it is the same chip/tech as I refer to above--as used in the Monoprice--but gets powered at the downstream end.

 

Lastly, you may notice a beta unit of the Pi2Design Mercury streamer in acrylic case on the floor.  On kind loan to me from @bobfa.  I have been having a lot of fun with it and its great appeal is that it is Ethernet to I2S (and AES, S/PDIF) with good clocks and regs and careful layout.  But it is crazy just how different server/player s/w and operating systems sound on it. Have so far tried Volumio and PiCorePlayer, the latter I am liking with both LMS and Squeezelite running on its Pi Compute4 module.  With a great PS it is not within a hair's breath of my Pareto NUC/Roon setup, though @lmitche will be doing a major AudioLinux upgrade for me tomorrow and that is likely to move the goal.

 

It has been great to have some days to play around, experiment, and enjoy more music--though I would welcome a few more JS-2 orders this month... 

Can't wait until @JohnSwensoncomes down from Washington for a 4 day visit in June.  It has been a long time since he heard my system, plus we are likely to be playing with some other secret prototype goodies! 

 

Have a great weekend everyone.

--Alex C.

 

 

 

[Superdad]

41 minutes ago, Exocer said:

Did you mean “now” instead of “not”?

Yes thanks. The Mercury is getting very close but it’s not quite there—at least as presently set up. I need to get another couple of microSD cards to continue experimenting with OS and players. 

[Superdad]

10 minutes ago, oneguy said:

…I probably never would have sprung for the Mercury but I think I’ll be happy I did. 

I am certain you will be VERY happy with it.  Packs in a lot of intelligent design and fine parts choices for a curiously low price. My only concern is how Micheal Kelly is going to profit and keep up with support at that price. 

[Superdad]

1 hour ago, Exocer said:

Be sure to try GentooPlayer.

Indeed that’s next up on my list as some others have spoken very well of it in comparisons. 
What server/player s/w are/were you using with GentooPlayer?

[Superdad]

2 hours ago, di-fi said:

'' HDMI cable (wow those cables can sound really different!)''

Do you mind sharing what is/are a keeper(s), in your setup between SingXer and Holo Spring Level 3?

 

The only two HDMI cables that I have spent a fair amount of time with as I2S links are the Wireworld Chroma 7 (12-inch) and the Pangea Audio HD23PC Premium (0.6 meter).  Very different construction between the two.  I had been using the Wireworld for 2-3 years--and had the Pangea (highly recommended to me by someone here on the forum) in the box for about that long.  As mentioned, I've recently had more time to play around and tweak (and other things I've done to my system lately have made it ever more sensitive and responsive), so I finally put in the Pangea.  At first its forwardness (in comparison to the Chroma 7) was almost overwhelming. Very tactile and dimensional. I went back and forth a few times to be sure it was not a bad thing. Now, with some time (break-in or just my ears getting used to it and discovering all the details) I am fully convinced it is the more revealing cable.  Go figure.

[And of course such talk of HDMI cables--and all this other stuff with software, clocks, power supplies, etc.--would give all the measurement/"objectivist" people massive fits. But if someone was here with me in my room right now, listening to favorite Nina Simone, Peter Case, or Peter Gabriel albums (oh the bass!), there would be nothing but grins.]

[Superdad]

1 hour ago, MarcelNL said:

In many implementations I2S cables ahave a length limitation, don't you think that the difference in length (12"is what 33cm or so?) versus 50 cm had a part in any sonic differences?

I believe it.  Yet:

a) I2S over HDMI is driven by an LVDS driver chip, so I think the impact of length will somewhat depend on that part--as well as the LVDS receiver chip at the DAC;

b) In my--extremely limited--experiment, the Wireworld Chroma 7 was the short (12") cable yet the 24" Pangea is my clear preference.  Unfortunately the Pangea Premier SE is not available in any shorter length.

 

BTW, I a open to suggestions of other HDMI cables to try for the I2S link from DDC to DAC as it is clear the Holo Spring is quite sensitive to that link. Suggestion only of cables heard first-hand ear please.  

[Superdad]

1 hour ago, auricgoldfinger said:

I am using these optical HDMI cables in my home theater setup and like them a lot.  They may be overkill for what you are doing, but I thought you might be interested nonetheless.

 

Those are interesting, thanks!

But keep in mind that the I2S signal--even driven an LVDS--is a delicate thing. HDMI cables were chosen for it simply because the HDMI spec calls for well shielded, high-bandwidth differential pairs--and both cables and PCB connectors  were plentiful for it.  

Truly no relationship to the video signaling as you know.

 

So active optical cables--with all their transceiver circuits--are probably going to sound pretty bad for an I2S link. 

Plus the HDMI/I2S output side of my modified Singxer DDC is already isolated (and floated/isolated LPS-powered) from its USB input stage. So I don't see how another active stage of isolation (via the optical cable)--with its own circuits--is going to benefit.

[Superdad]

11 hours ago, MarcelNL said:

I have experimented with an LVDS to HDMI convertor...

Not clear what sort of device you are referring to.  I2S over HDMI is by definition an LVDS signal, produced by an LVDS driver chip at the sending end of a DDC. [Edit: I do notice that Pink Faun is unique in optionally delivering TTL I2S on an HDMI cable--but compatibility with other devices will be limited if chosen.]

 

4 hours ago, MarcelNL said:

talk w Cees Ruitenberg from Metrum and Sonnet about I2S and he'll tell you LVDS is no good. I tend to believe him in favoring LVCMOS as it for sure is much less affected by cable length although I lack the detailed insight in the electronics behind either implementation and finding out all key parameters via trial and error is challenging.

I am not one to question Mr. Ruitenberg but perhaps you misunderstood his reasons for preferring CMOS/TTL to LVDS for I2S.  Differential signaling is far less susceptible to common-mode noise and EMI and will do better over length than a single-ended CMOS or TTL signal.

Perhaps Cees simply does not like the available LVDS driver and receiver chips. Such would be a more plausible explanation for his preference for I2S on single-ended wiring with RJ45 plugs.  But for those you really do want to keep cables short.

 

29 minutes ago, MarcelNL said:

Multiplying a clock signal is not what you want if you go to the length of investing in a Mutec, most/many I2S signals do not carry the master clock as far as I'm aware.

An audio sample-rate-related clock is absolutely part of the I2S signal protocol!  

As to what each DAC does with the data and clock coming in I2S, that varies greatly from DAC to DAC. Some DACs will asynchronously reclock to some other, non-multiple rate; some will just double, and some will directly use the data with the incoming clock.

 

What is only VERY rarely done--but in fact would be much better--is when the DAC's master clock is fed back upstream to the I2S source to be used as the master clock.  Only a very few DACs do that.  Would have been great to have that as part of the standard for external I2S.  (But of course there is no "standard" for external I2S.). 

 

Most of the better USB>I2S input boards (or simply USB inputs that DAC designers implement on the main board) allow for DAC master clock to be fed into the USB MAC processor chip for I2S. This is why, if all elements (isolation, power, clocking, etc.) were done exceedingly well, a DAC's USB input could easily result in better SQ than an externally delivered I2S, regardless of it being LVDS or LVCMOS.

 

8 hours ago, MarcelNL said:

ask Pink Faun? They do custom jobs...I see one minor issue and that is the frequency of the OCXO in the I2S bridge, it is using 24.xyz Mhz. and most external clocks (as far as I am aware of them) do not provide that exact frequency.

Well there are plenty of external reference clocks that deliver audio sample-rate-related frequencies (Esoteric, Antelope, dCS, some AfterDark models, etc.).

What does puzzle me is that the Pink Faun I2S Bridge boards seem to have only a 24.576MHz clock--which covers sample rates in the 48KHz family (48/96/192, etc.), with no 22.5792MHz clock to deliver in the 44.1KHz rate family (44.1/88.2/176.4, etc).  And I doubt they are doing any non-integer clock dividing to obtain a clock for the 44.1KHz family. Can't imagine that the board is limited to outputting in the 48KHz family. 

 

 

[Superdad]

41 minutes ago, MarcelNL said:

How Pink Faun makes do with that frequency clock is a mystery to me, all I know is that they use the HDA CMedia 888 chip that requires 24.576Mhz to work,

Ah yes, the all-in-one Cmedia CM8888 uses an internal PLL to synthesize all output clocks. With that chip’s wide capability—much of it aimed at pro-sound I/O applications, I am guessing Cmedia chose 24.576MHz as input clock frequency simply because, for pro-sound use 48KHz-family rates are more popular, and for that family the PLL can simply integer multiply the clock. Hopefully the PLL does not add too much phase-noise/jitter to the reference clock when producing I2S for Redbook rates.

[Superdad]

1 hour ago, bobfa said:

The LP has a huge advantage, it has artwork and text, plus whatever else is printed on the cover!

 

I bet you have this one in your collection Bob:

[Superdad]

1 hour ago, MarcelNL said:

Now we're on the topic of clocks, I happen to have a OCXO @ 24.576 Mhz lying around that I can sell, OR....see if I can put it to use on the Aorus Master X570 Mb I'm using, big problem is...how do I find out what freq the Mb clock has? Anyone here who knows a place to start looking?

I can 100% guarantee you that your computer motherboard does not use anywhere a 24.576MHz clock. That is an audio sample-rate-related frequency.

[Superdad]

1 hour ago, The Computer Audiophile said:

Here is what my friend uses to deliver heavy speakers. It’s really cool. 

https://youtu.be/iKk5t3EEksA

Just watched that whole video. Wow!  Any idea of price?  When I think about all the big heavy items that get moved onto the upper floors of luxury homes it makes me wonder about how such could be done before such ingenious devices existed... 

[Superdad]

On 6/3/2022 at 9:11 AM, RCDingen said:

What do you think the Taiko ATX is?

It's a switching DC to DC converter.

So the principle is the same as a switch mode power supply.

 

Hi Rob:

Sorry, but what you wrote is not true.  Many people incorrectly conflate DC-DC converters with SMPS (switch-mode-power-supply)--probably due to the word "switch," which is ironic since "switching" is much of what goes on in nearly everything in computer and digital audio.  They really are quite different and despite some (often mentioned in this thread) power supply manufacturers' fear mongering about the use of ANY DC-DC regulators, there is no harm to use of such if done carefully (DC-DC converter>filter>linear regulators).

In fact, in many cases a product design would be impossible without the use of DC-DC converters. Computer chips use a wide range of voltages at high current. For example, our own EtherREGEN uses 1.1V, 1.2V 1.8V, 2.5V, 3.3V, 5V.  While compared to the very high currents at such voltages that a computer motherboard draws, it would still take an large power supply in a separate case (either multiple transformers or lots of heat sinks) to do all those purely with LDOs.  Moreover, such would still be a significant compromise because of cable lengths and higher impedance to the actual chips needing the voltages.

 

Note that I am not speaking of power supplies that use AC>DC SMPS to directly front linear regulation. Those suffer somewhat from the same mail evil of an SMPS: leakage current.

 

I recall @JohnSwenson wrote more extensively on this topic a couple of years ago. I could not find the actual post but I did save a copy of what he wrote. I think it is worth reposting here so that people can develop a better understanding of the differences and usage. 

 

========

 

First off some clarifications about the differences between SMPS and DC/DC switching regulators. An SMPS plugs into the mains, it chops up the mains voltage into high frequency pulses, feeds that through a transformer, on the other side rectifies the high frequency pulses coming from the transformer, filters it into fairly clean DC, measures the DC and sends a feedback signal through another transformer or optical coupler to the front end to modify the pulse width so the DC output voltage is correct.

 

These have low level high frequency noise on the output AND input, but also have both high impedance and low impedance leakage current from the AC line to the DC output. This is what causes a lot of the issues with SMPS, NOT the high frequency noise on the output.

 

A DC/DC converter does NOT connect to the AC mains, its input is DC from some other power supply. Their purpose is to convert one DC voltage to another (either up or down). Their big advantage over a linear regulator is that the POWER is constant, not the current. With a linear regulator the current going in is the same as coming out. With a switching DC/DC converter the current going in depends on the power on the output.

 

Say for example you have 10V coming in and you want 1 volt coming out. If your load takes 1 amp, a linear regulator will need 10V at one amp on the input, that means 9 watts of power are dissipated in the regulator (ie a BIG heat sink). With a DC/DC converter the power on the output is 1 watt (1V x 1A = 1W). So on the input it takes 1W / 10V = 0.1A. Now in reality the converters are not 100% efficient, maybe say 85%, so the power needed by the input will be a little higher, in this case 1.15W, so the input current is 0.15A. This means the DC/DC converter is dissipating 0.15W instead of 9W, 60 times lower!

 

The DC/DC converter DOES have high frequency output noise, but it is usually at a much higher frequency than an SMPS. SMPS usually run at 40KHz to 70KH, DC/DC converters usually run at 500KHz to 1MHz. This is a big difference. At 60KHz a filter is fairly large and costs some money. The same amount of attenuation at 1MHz takes very small very inexpensive components. The result is that IF you use a filter on the output, you can get a huge attenuation for very small board space and cost when using a DC/DC converter. Of course you DO have to spring for the filter, very cost constrained devices usually don't.

 

The DC/DC converter does NOT create any extra leakage since it is not connected to the mains. Whatever leakage exists from the power supply is still there, the DC/DC converter does not attenuate it, but it doesn't increase it either.

 

With a DC/DC converter you can always add a linear regulator after the converter, good ones can decrease the high frequency noise from the converter by 80-100dB. So a combination of the filter AND a linear regulator reduces the high frequency output to much less than the inherent noise of the regulator, it is essentially gone. So if properly implemented a DC/DC converter does not have any down side and it drastically reduces the amount of heat that has to be dissipated.

 

All that said, very low cost devices are not going to go to any of those measures, they are going to use a cheap DC/DC converter and and feed the output directly to the chips.

 

On the etherRegen, there ARE a few DC/DC converters in the design. But they have the good filters and very good linear regulators after the converter. I have tried using some very sensitive test equipment and have not seen ANY sign of the DC/DC converter on the final DC.

 

One other issue with DC/DC converters is EMI, the converter can radiate high frequency signals that can be picked up by other traces on the board. I am using some very special converters that have extremely low EMI, I can JUST barely measure it, where I can measure strong emission from other converters. Even though the EMI is so low I am laying out the board so that pickup by other signals is quite small. Again I have not been able to see any hint of this in prototypes.

 

The whole reason for using the DC/DC converters is to drastically cut down on the amount of heat the box has to dissipate, AND the high cost of getting the heat from the regulators TO the heatsinks.  I'm quite confidant that this is done in such a way that there will be NO impact of this on the operation of the device.

 

John S.

===================

[Superdad]

3 hours ago, di-fi said:

you wrap yourself in yellow plumbers Teflon tape possibly with cotton.

If I did that it might take a long time to get dressed in the morning! 

But seriously, plumbers tape will keep your electrons from leaking…

[Superdad]

9 hours ago, Gavin1977 said:

Uri Geller here I come!

Well it seems like a good bit of esoteric audio is "mind over matter" anyway, so Uri might fit in fine amongst our crowd. 

 

And if Uri is not available, just pick up an inexpensive copper tubing bender tool:

 

[Superdad]

8 hours ago, drjimwillie said:

Have you guys seen this direct attached copper DAC that they are talking about in the extreme thread? 

It looks like a fiber, optic transceiver, except it has a copper wire between each end.
 

I am not sure how to use it, but it looks like you just plug it in where you would typically have your fiber optic line. 
 

I currently have an Sonore optical module and an EtherRegen.   I think I would plug this DAC in, where I have my fiber transceivers. 
 

I wonder why this would be better than an ethernet cable with a Telegartner Ethernet cable?  I have one of these cables and the punch down looks like a circuit board. 

 

 

 

https://www.fiber-optic-solutions.com/dac-cable.html

 

Just like SFP modules with RJ45 Ethernet ports, those DACs (Direct Attach Cables) are terrible in comparison to a fiber optic SFP (or to an "AOC", Active Optical Cable, which is an actual fiber optic cable with SFP optical transceivers at hard-attached at both end).

 

Any SFP (Small Form Pluggable) that has a copper/CAT/RJ45 connection (hardwired in the case of these "DAC" variants) contains the PHY/receiver chip and a clock inside the module. The compromises are numerous, and include the crap clock, crap regulators (which must all get supplied and step down from the 3.3V that the switch/endpoint is supplying to the SFP cage), and then the extra PHY that has to go from copper to SGMII/fiber (2 differential pairs, to feed that port on the switch chip) right there in the SFP module.

So yes, the data bits will get there, but the results (owing to the host of various ground-plane-noise/clock-threshold jitter factors) won't be sounding good. 

 

Best to stick with either real fiber optic or straight RJ45 copper ports. 

[Superdad]

4 hours ago, Nenon said:

per Taiko the Passive version of the Direct Attach Cable is "dramatically better then any RJ45 terminated UTP or STP cable".

Sorry, but despite the moniker of “passive”—versus the longer distance “active” versions—there is nothing passive about those Direct Attach Cable transceivers that stick into an SFP+ or QSFP cage.  They contain—at minimum—an RGMII to SGMII PHY transceiver chip, a 50-cent clock, a set of magnetics, and cheap power supply voltage regulators. All crammed onto a tiny board and all powered by the same 3.3V feed to the cage. So while power consumption of whatever cable they chose may be low, the noise and embedded low-frequency phase-noise/jitter performance is not going to be great.

 

By comparison, an optical SFP/SFP+/QSFP transceiver is a much more “passive” device in that its fiber to dual or quad differential pair transceiver chip runs free of any clock—direct into whatever silicon is receiving it, where it then is clocked.
[I state it this way because the output of a fiber optic SFP transceiver is not inherently Ethernet or any particular protocol. Sure it generally is fed to an Ethernet switch chip/MAC processor’s SGMII/QSGMII port, but those lovely differential pairs could just as easily be carrying data bound for some other protocol. (USB3.0 SuperSpeed being an example as it two differential pairs—one for each direction—matching nicely with SFP+ transceivers.)]

 

[Superdad]

1 hour ago, jean-michel6 said:

For connectors the option are the aviation type , the XLR and the Jaeger.

4-pole Neutrik SpeakON are far better than either the “aviation” plugs or XLRs, plus cheaper than Jaeger and easier to work with large gauge wire.  Very secure, full-contact line contacts. Wide variety of readily available jacks and plugs.

[Superdad]

26 minutes ago, jean-michel6 said:

The speakon connector from Neutrik seems to be a good connector for the Ulps psu .

 

However on the neutrik documentation they have written this :

 

speakON is NOT to be used as an AC mains or power supply connector!

 

Does somebody now why  ? @Superdad Any idea as you recommend this ? 

 

The speakON plugs/sockets are rated to 40A RMS per contact and available as 4-pole and 8-pole.  The PowerCON connectors are only ever 2-pole and rated to 16A.

Both connector series are used extensively in professional sound reinforcement applications (think concerts and the like) and Neutrik (as well as the regulatory agencies) do not want someone accidentally mixing up AC mains and speaker connections.  So they use different systems that won't plug into each other.

There was some more discussion about this here: https://www.eevblog.com/forum/chat/neutrik-speakon-vs-powercon/

 

The 4-pole SpeakON is fantastic for star-quad DC cable application. Although the terminals are screw type, it is easy to remove the screws/clamps and solder big wire right into their big terminal cups. I bet you could stick an 8AWG into one cup. Times two for star-quad pairing would make for a beast of a wire!