Raspberry Pi streamer DAC builds

MikeyFresh

Moderator
Staff member
So...two Millett USB 5v boards then? ;)
And not to further complicate things until the actual Group Buy with prices is announced, but I see in the development thread as recently as August 2018 that a new IsolaterPi II was being touted, this is like the old version in that it does not have the FIFO or reclocker built-in.

Not sure if this was shelved, I don't see why it would have been, but if this is produced for the upcoming GB it would provide a lower cost option than the full on FifoPi.

Additionally, the post I read made mention of the ability to power the RPi through either the non-isolated GPIO, or through +/- 5V through holes on the board right next to that non-isolated GPIO (bottom right-hand corner of the board in the photo below, just right of the non-isolated GPIO):

IsoPi2.jpg

That post says it does sound better that way than through the Pi's micro USB input.
 

Thermionics

Post Whore In Training
And not to further complicate things until the actual Group Buy with prices is announced, but I see in the development thread as recently as August 2018 that a new IsolaterPi II was being touted, this is like the old version in that it does not have the FIFO or reclocker built-in.

Not sure if this was shelved, I don't see why it would have been, but if this is produced for the upcoming GB it would provide a lower cost option than the full on FifoPi.

Additionally, the post I read made mention of the ability to power the RPi through either the non-isolated GPIO, or through +/- 5V through holes on the board right next to that non-isolated GPIO (bottom right-hand corner of the board in photo):

View attachment 10300

That post says it does sound better that way than through the Pi's micro USB input.
You're breaking my brain! ;)
 

MikeyFresh

Moderator
Staff member
I think it's wonderful that we can start with these credit-card sized boards and end with something that has to be transported in the back of a pickup truck :)
Safe to say you won't be building the dual battery bank version then?

LiFePO4-x2.jpg

Ian's take on this set-up: "This configuration can save a lot of space, looks very compact
"

I guess it's all in the eye of the beholder.
 

MikeyFresh

Moderator
Staff member
You're breaking my brain! ;)
Well lets finish that process then with this little blurb from a Nov. 2018 Ian post:

"Note1* All old items will be still available, which are here:"
Ian asynchronous I2S and S/PDIF FIFO KIT group buy

So he apparently does have at least a few left of the pieces in the 2017 Group Buy, from which I bought the original IsolatorPi. Perhaps he also did an additional production run on the most popular of those items, hence the talk last summer of IsolatorPi II.

We should know more in about a week if my estimates prove accurate, I think he is very close to releasing the pricing and final details of the Group Buy 2019.
 

MikeyFresh

Moderator
Staff member
Quick update on the IanCanada 2019 Group Buy:

Ian did the production run based on numbers from the "interested" list, has already received those boards, and is in the midst of QC testing and documentation. He hopes to have that and the finalized pricing completed by the end of the week, and if so can likely commence the GB sometime early next week.
 

MikeyFresh

Moderator
Staff member
A friend of mine in California is a Roon user and wanted to add a Roon Bridge endpoint player to his bedroom system.

He has experimented extensively with the now discontinued Chromecast Audio and a Toslink connection to a cheap FiiO DAC, but was having constant issues with pops and clicks marring the sound.

He finally gave up on that, the CCA is a cool little $35 streamer, but it was never intended by Google to be Roon compatible and even though there is a work around that enables it, that solution is a bit kludgy, and it did not work well with the little FiiO Toslink DAC he had hoped to use.

I decided to put together and send him a Raspberry Pi based solution whose software is developed in Holland, called RoPieee. OK dumb name, but the software is well received and much easier to install and configure as compared to the official RPi disk image offered by Roon.

I picked out a good looking but inexpensive $13 aluminum case for it that would be an aesthetic match for his iFi nano iDSD DAC:

RoPieeePi (2).jpg

I slapped it together, flashed a microSD card with the RoPieee software, and then packed it up for Priority Mail as I am not a Roon user and thus have no way of actually testing anything. I took a leap of faith and dropped it off with the USPS.

Two days later it was delivered in San Diego, my buddy connected Ethernet and USB cables, and powered it up. After sniffing the unit's IP address using the Fing app, he was able to dial into its simple web browser based settings interface and a few clicks later, then make the final configuration on his Roon Server's GUI. It took him less than 10 minutes from unpacking to listening to music, all PCM sample rates and DSD are supported.

Here is his crappy camera phone picture of the initial set-up in the bedroom:

RopieeePi (1).jpg

Makes a nice little bedroom streamer set with the iFi nano iDSD, he says it sounds great and highly recommends it as a cheap Roon endpoint.
 

MikeyFresh

Moderator
Staff member
IanCanada released what he is calling estimated pricing for his imminent GB2019, with final pricing coming "very soon".

This tells me he's almost but not quite done with his QC testing of the production run, and therefore can't commit to pricing as yet, but in all likelihood this will be the final pricing:

Estimated GB2019 pricing:

A1. FifoPi 768KHz I2S/DSD/DoP FIFO with isolator and dual XO, estimated $99-(Special price for this GB, regular $135-)
A2. LiFePO₄ pure power supply with 5 output rails (no batteries), estimated $199-
A3. ESS controller, estimated $39-
A4. Dual Mono ES9038Q2M DAC HAT, estimated $85-
A5. ES9028Q2M DAC HAT, estimated $49-
A6. I/V STD standard OPA I/V stage, estimated $35-
A7. Transformer I/V PCB mini KIT, estimated $19-
A8. ESS controller extension kit, estimated $12-
A9. Package of dedicated CCHD957 XO adapter kit lot of 2, estimated $8.9
A10. Package of OPA1622 adapter PCB kit lot of 5, estimated $9.8
A11. 2” double-ended silver plated U.FL coaxial cable, estimated $2.8
A12. 2.5mm metal standoffs for RPI lot of 4 sets, estimated $2.9
A13. LT3042 low noise regulator PCB, free
A14. I/V STD standard I/V stage empty PCB, free

Unfortunately I can't begin to answer questions about all of the above, those answers are scattered across 2 or 3 different threads at diyAudio.com over literally 2 years time (since shortly after his GB2017 ended) so it would be best to ask over there if on the fence about something as the GB2019 will commence very soon, I'd say in just a few more weeks or so.

I'm very pleased the FifoPi (A1 above) came in at $99, that's what I was hoping for and seems very reasonable when considering the original IsolatorPi (with no FIFO or reclocking) was $49, so the $99 for this upgraded and more sophisticated version is great.

I had no idea what to expect on the LiFePO₄ pure power supply (A2 above), and at $199, it ain't cheap when you consider it comes with no batteries. Each 26650 LiFePO₄ A123 Systems cell of that kind is about $14 depending on the supplier. The board takes 10 cells, so $140 + shipping for the cells. I'm not surprised as this is a very ambitious piece with sophisticated hardware and software overcharge/over discharge protection etc... and just a much larger board with a lot of components on both sides. I'll have to think hard about that one, especially since...

The dual mono DAC card itself is reasonable at $85 (A4 above), but the preferred Transformer based output stage (A7 above) comes without the trafos themselves, it's a kit and you bring your own. Good in a sense you can pick what fits your budget, bad in that Lundahls of this type are pricey little SOBs (K&K list the LL1544a at $85 a pop). Also potentially bad is ruining such a part if inexperienced on the do's/don't do's of installing it correctly, I have never built a unit with anything like that and so there is some hesitation there.

Anyway, there is the estimated pricing, with final pricing now just days away on the IanCanada GB2019.
 
IanCanada released what he is calling estimated pricing for his imminent GB2019, with final pricing coming "very soon".
Is the group buy still open to newcomers, and I ... append my diya username, and the item(s) I'm committing to? Then email details to Ian under separate cover? Do I have that right?
(I'm just getting caught up here, and that diyaudio thread is daunting to find the actual join directions).

Hoping for a FifoPi.
Edit: Aw heck, here goes nothing... added my name to the list.
 
Last edited:

MikeyFresh

Moderator
Staff member
Is the group buy still open to newcomers, and I ... append my diya username, and the item(s) I'm committing to? Then email details to Ian under separate cover? Do I have that right?
(I'm just getting caught up here, and that diyaudio thread is daunting to find the actual join directions).

Hoping for a FifoPi.
Yes you can just add your screen name to that "interested" list, and then join the GB2019 once it is made available, probably just a couple of days from now when the QC testing is done and the pricing finalized.

You don't need to email Ian now, he will post an Order Form once the GB2019 is actually launched, at that time you'd fill out the order form including PayPal details, and he will email you a PayPal invoice based on what you've ordered.
 
Thanks for clarifying - I hadn't logged in over there since 2016 - feeling pretty out of the loop. And I didn't want to be that guy showing up a day late asking "Does this work with my iphone??" I've seen how even the simplest group buy turns into a cat-herding nightmare, however I'm grateful to those folks crazy enough to launch them.
 

MikeyFresh

Moderator
Staff member
Well the testing/QC and final revisions to the documentation necessary before IanCanada's GB2019 can be launched are taking a bit longer than I had hoped.

In the meantime he did post draft versions of the documentation, if it's like the GB2017, these drafts will be proof read/edited/revised by longtime diyAudio contributor Greg Stewart before final release. So far no Draft manual for the actual ESS DACs have been posted.

Attached below are the Draft documentation for some of the GB2019 products, as well as the final release documentation for IsolatorPi II which is now confirmed for this GB at $49 despite not originally being listed. It is almost identical to the original IsolatorPi, and one additional note there is that Ian does recommend it instead of the more expensive FifoPi for use with any Master mode DACs such as HiFiBerry DAC+ Pro, or the Pi2 Design 502DAC.

Apparently the Master mode DACs are incompatible with FifoPi when run in Master mode, and though there is a way to run those DACs in slave/sync mode, that rather misses the point according to some and the best route there is to just use IsolatorPi II at $49 instead of FifoPi at $99. Greg Stewart does differ on this point, and actually prefers many Master mode DACs run as slaves, however he is a special (unique?) circumstance given the absolute extreme levels of power supply implementation he is willing to do, not to mention FIFO buffering, etc... so the whole nine yards there in his experiments with Master mode DACs running as slaves.

I would urge anyone with questions about the above, or really any questions about specific compatibility with any item listed in the forthcoming GB2019 to ask now in the diyAudio threads to confirm.

Also one other detail that is now making a bunch more sense to me regarding FifoPi, and that is the included clock/oscillators at $99 are not the Crystek CCHD-957 that had been pictured throughout the development process. Included are a good quality but generic pair of clock oscillators. Ian was quick to say these generic clocks do perform quite well when paired for instance with very high-quality powering schemes such as the new LiFePO₄ battery supply, but not as well when used with typical standard/generic RPi power sources such as most cheap wall wart SMPS.

I did not understand how Ian could possibly offer FifoPi at $99 with those Crystek clocks, and it turns out he can't as the board uses two of them and those parts are about $28 each. He did however make the board design socketed, so the end user can substitute the Crystek or any other compatible oscillator of their choice with no soldering to the board itself, just pull out the little plug-in clock adaptor board and put a new one on. What isn't clear to me as yet is the procedure for mounting any "bring your own oscillators" to a blank clock adaptor board ($8.90 as currently listed). That does certainly involve soldering, and could be similar to a procedure Ian has shown previously with other little adaptor boards where SMD parts are mounted to the board by baking them in a regular oven using a little solder paste.

I hope to know more on that soon, but I doubt my kitchen oven will be suitable. It is decidedly not a modern appliance, no precise digital temp control or anything like that, so I'll probably have to invest in a little soldering/reflow oven dedicated to this purpose.
 

Attachments

I'm looking forward to the DACs, but I'm not doing the battery supply. As a diy tube-amp solder slinger, I have lashed together any number of 450V power supplies, but .... Lithium batteries scare me. They hold a whole bunch of energy and have a few failure modes that are quite alarming. Granted, I've already got quite a number of them in the house, but - I don't really trust those, either.
 

MikeyFresh

Moderator
Staff member
Lithium batteries scare me. They hold a whole bunch of energy and have a few failure modes that are quite alarming. Granted, I've already got quite a number of them in the house, but - I don't really trust those, either.
I hear you, and that's no small consideration.

Do I really need my digital front-end to be powered by pure DC? No, but I think I'm going to do it anyway and hopefully not come to regret it on any level. I did get a taste of this trying a pack of 6 Eneloop NiMH AAs in series, about 8.4 volts at full charge, to power my Sonore microRendu, which runs on anything between 6-9 vdc. With the microRendu driving a USB bus powered DAC, this lasts a little under 6 hours and sounds absolutely sublime, pure battery power is ridiculously good for digital, but often not that practical.

So the above was a taste and now I want more of it, Ian's board goes to the next level in that each of the other boards in the set-up can be driven by the battery bypassing all regulation. In my trial above there is of course still regulation going on inside the microRendu itself in the form of an LDO, I believe it is the TI TPS7A4700.

But yes I agree having more and more rechargeable Lithium batteries accumulate in one's household is generally speaking not the best idea. It should be noted the type of cells employed in Ian's board are not run of the mill Lithium-ion batteries using the more common LiCoO₂ (lithium cobalt oxide) chemistry found in cell phones and the like. They are Lithium Iron Phosphate (LiFePO₄ also called LFP) that are said to offer the combination of low-cost, low toxicity, high-performance, and better long-term stability/safety as compared to the more common and seemingly less stable LiCoO₂ chemistry that has the advantage of greater energy density, lower self-discharge, and zero memory effect.

LiFePO₄ is I believe the kind of cell now being used in Tesla automobiles for instance, which to me is a strong suggestion they are much less of a safety concern than the other more common type of lithium battery chemistry which has had it's share of issues in certain devices over the years. EDIT: It looks like Tesla is using a different chemistry entirely (LiNiCoAlO2 or "NCA").

With the additional safety and stability of LiFePO₄ comes the penalty of lower energy density, and at least some potential for memory effect if the charge/discharge cycles are not done properly. This is where I'm rolling the dice that Ian's board has the tech to address this very real issue, he has a sophisticated battery management controller built-in, though the complexity in getting it programmed properly for my particular use pattern might be a challenge. Could be a big pain in the ass that results in dead cells of the $14 each variety, or it could work a treat in which case these cells will last a really long time given the amount of use I'm likely to demand of them.

Let's hope it's the latter, as the cells need to be ordered with tabs already spot welded to the terminals, and those tabs need to be soldered to the board by me. The last thing I want to do is go troubleshooting which cells are dead, de-soldering and replacing them. That will suck whenever it occurs, hopefully it'll be many years down the road if I get this right from the start, these cells can be recharged 2000-3000 times.
 
Over on reddit's /r/ebikes forum, seems like there's one post a week from some enthusiastic new owner of a spotwelder trying to figure out how to stick his battery pack together. No Bueno.

(To cop to the true level of my hypocrisy - I'm waiting to take delivery of a Tesla PowerWall system. The whole house is going to be battery powered (well, invertered back to AC). Presently they're diverting all battery production to the Model 3 line, so I wait.)
 

gable

Senior Member
I finally sliced off a bit of time to build the TDA1387 DAC hat yesterday. Hopefully I can sneak some time this week or next to slap it in the proto chassis.

The tentative plan, at least for now...

Pi 3B+
Allo Kali reclocker
TDA1387 DAC hat

Each will be powered by individual, 5v regulated power supplies, ultimately at least. I may eventually power the 3.3v sections individually as well, who knows.

IMG_1186.jpgIMG_1187.jpgIMG_1185.jpgIMG_1178.jpgIMG_1184.jpg
 

MikeyFresh

Moderator
Staff member
The IanCanada Group Buy 2019 has commenced.

I guess here goes nuthin'. I'll need to figure out how to both afford and safely construct the LiFePO₄ battery power supply, and the Lundahl LL1544a transformer based analog output stage among other things. Oh and then the small issue of a proper case to fit it.

I will build 2 units: one with the ES9038 dual mono DAC and a transformer output, the other with the ES9028 DAC and active I/V output with battery power supply.

The GB2019 will give me about everything I need for that except the battery cells, and the trafos. Lord help me, this has turned into a very expensive science project.
 

gable

Senior Member
The LiFePO supply looks awesome, so does the transformer i/v. Ian sure does put together the best group buy's, what a great asset to the DIY community.

Very interested to read about your impressions of the new gear Mikey!
 
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