A NOS 192/24 DAC with the PCM1794 (and WaveIO USB input)

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#2,121
Hi James,

I've not done it. I was hoping to jump the gun with the isolator all at once. Without foresee I2s direct connection, I previously soldered WaveIO I2S direct to DDDAC's main board. Going to be challenging to unsolder them apart, nonetheless I will give it a go tomorrow. For connection between the PI and DDDAC via I2S, I will follow Palmito and your posts with the uploaded photos. 😉
Can I ask which s/w player are you using and if DDDAC is detectable? I am currently using Volumio and WaveIO is detected under LM20 driver.

Regards,
Chanh
 
#2,122
Chanh said:
Hi James,

I've not done it. I was hoping to jump the gun with the isolator all at once. Without foresee I2s direct connection, I previously soldered WaveIO I2S direct to DDDAC's main board. Going to be challenging to unsolder them apart, nonetheless I will give it a go tomorrow. For connection between the PI and DDDAC via I2S, I will follow Palmito and your posts with the uploaded photos. 😉
Can I ask which s/w player are you using and if DDDAC is detectable? I am currently using Volumio and WaveIO is detected under LM20 driver.

Regards,
Chanh
Click to expand...
although most people have connected I2S from their Pi to the mainboard using the same 1 pin connector as for the WaveIO. I don't see any reason why you can't use the other set of input connectors right next to that and just leave your WaveIO powered off. All the required inputs are there and ready.

I'm using PiCorePlayer s/w and selecting the output as Hifiberry I2S and it all just works perfectly for me with no extra work needed. PiCorePlayer is a Squeezebox player software, so you will also need to have a Logitech Media Server on your network. If you don't have this or you don't want to install LMS on something else on your network, you could run Squeezeplug software, which is a little more complicated to set up, but you can also install the LMS onto the Pi so it runs at the same time with this.

I would get it working directly with Pi to DDDAC first, then add in the isolator inbetween afterwards when you have the first stage working.
 
#2,123
Chanh said:
I read Enrico has finally has his Amanero Isolator/Reclocker from Acko up and running after much efforts. Is there an easier alternative?
Click to expand...
If you can solder smt parts (i.e., a hot air gun is highly recommended, along with solder paste) then the S03 is very easy to put together, especially if you start from scratch and just put the solder paste on all the pads you are going to put parts on, place the parts and then solder once with the hot air gun. With hot air there's much less risk of damaging a $25USD clock...

The SO3 thread has a detailed writeup on configuring it.

I'll let Enrico comment on his build though, but I think he is doing world cup watching lately and has no time for audio... 😀
 
#2,124
Chanh said:
Hi Palmito,
I did send them an online technical query via their website. There was no email address provided but online form via contact us. Til date, no response!

I hope Miero & Russ can come up with a suitable BBB Cape that would work with Doede's DDDAC. For the mean time, I'd be grateful for the guidance getting my Pi and DDDAC via I2S with a decent isolator. I read Enrico has finally has his Amanero Isolator/Reclocker from Acko up and running after much efforts. Is there an easier alternative? 😕🙁

Regards,
Chanh
Click to expand...

Hi Chan,
If you need a simple isolator you can use the DIYINKH pcb (for free) with just an isolator chip, 2 caps and 2 connectors. If you look in the page 160 of this thread, I try to explain how can make the rpi/isolator/dddac working. You have some sw mods to do but is not really difficult.
I hope this can help you
Regards,
Enrico

PS: Just for your info the S03 is a step ahead and is not so difficult to realize. For the rpi with the dddac you no need to install all the components... When I have some time I will prepare the modified schematic and send here
 
#2,125
palmito said:
If you can solder smt parts (i.e., a hot air gun is highly recommended, along with solder paste) then the S03 is very easy to put together, especially if you start from scratch and just put the solder paste on all the pads you are going to put parts on, place the parts and then solder once with the hot air gun. With hot air there's much less risk of damaging a $25USD clock...

The SO3 thread has a detailed writeup on configuring it.

I'll let Enrico comment on his build though, but I think he is doing world cup watching lately and has no time for audio... 😀
Click to expand...

Dear Palmito,

You are right as usual 😀.. is not time for me now to prepare some detail for the S03 but I will do. 🙂
 
#2,126
Many thanks Gents for your inputs! I will first try out the Pi i2S direct to DDDAC without the isolator. Hopefully, I will get the SO3 alike up and running after the Brazil 2014, when Enrico is able to draft his working isolator schematic and share his lesson-learnt to us all here. 🙂

Kind Regards,
Chanh
 
#2,127
Chanh said:
I will get the SO3 alike up and running after the Brazil 2014, when Enrico is able to draft his working isolator schematic and share his lesson-learnt to us all here
Click to expand...
This should get you started. I think Enrico just left parts you don't need for Doede's dac out (but you should wait for his advice on this), but if you ever want to use the S03 for a dac that requires MCK you will need some of those parts, so I put them in (this is for an older version of the S03, but most of it still applies I think):

http://www.diyaudio.com/forums/group-buys/227502-amanero-isolator-reclocker-gb-98.html#post391698

The flipflops you can get from Potato Semi directly from ebay.
 
#2,129
dwjames said:
I now have 24ohm, 33ohm and 47ohm 50w resistors, plus some heatsinks to play with 🙂 If I only need to draw 100mA to get the choke input to work properly, I might try to use the 47 and 33 in series to give 80ohm and pull 12v / 80ohm = 150mA. I also have some 1uf caps to try placing before the first choke.

I can change the location of the bleeder no problem, but if I attach it after the first choke, then the second choke won't see the load will it? When you say this may work better, is there something I can test or measure to see which works out best?

Also, I haven't decided proper locations for the power supply components yet. I can easily mount that new strip of board on the front of the case so that the wires for the bleeder are much shorter if you think that will help?

New panasonic caps sound interesting. Do you have details of the specific model?
I see Panasonic now offer an OSCON solid polymer cap with reasonably high capacitance and very low ESR called the SEPC
OS-CON Aluminum-Polymer Solid Capacitors - Panasonic
If what Guido says is right and a shunt regulator prefers an OSCON type cap before it regardless of whether it's powering an analog or a digital stage, maybe these are a good option for the mainboard and most of the DAC electrolytics for those using shunt regs?
Click to expand...

Hello James,
If you put the bleeder after the first choke it will function like a choke input. If you put it at the second choke it will be choke input too but you will loose some more tension. I always did hear that transformer rectifier choke and first cap should be as close to each other as possible. Because there the ripple current is at the highest level. You should drill some extra holes so you can turn the choke to minimize hum. If i am right you can measure it with a multimeter. Ask someone else to explain or use google i forgot lol.
I did read some more on caps it appears esr isnt the only thing to look for.If Guido says the oscon are good i think you should believe him.
I would also try to wire the chokes according to their pdf file. I think they should know how to do it. Maybe there is no difference but i think there will be. Choke input is heavy work for a choke so every detail will be magnified.
If you need an aluminum plate to mount your stuff including turning it 90 degrees i can help if it will fit in a sturdy envelop. I would go for everything in one '' box '' maybe some screening for chokes and power transformer.
Sincere greetings, Edward
 
#2,130
A single 80 Ohm bleeder is enough to make the choke input right with a one deck DAC ?
With a draw of 150mA, it looks like with 2 decks there's no need for a bleeder anymore ?
And one more question, what if the inductance isn't high enough to make the best regulation available, is it a problem for our expensive local regulators ?

I'm making an order today with components to assemble my choke input. I think I'll order one high rated wirewound, but still unsure if I'll use it or not. Maybe it'll be nice to try with and without !
 
#2,133
Hello,
If you use a bleeder there will slways be a current flowing. If you use 80 or 100 ohm there will be enough current. The higher the current the bigger the ripple so i would use that will give 150 mA that is more than enough.
If you use a bleeder the tension will go up gently it is better for the caps and i think it is also better for the dac. Most things break down during switching on.
If there is less current through the choke the inductance will also be higher so better filtering.
SO if there isnt a bleeder and you switch on the dac. Tension will go up a bit higher probably and then go fown when thevdac starts working. The bleeder will always work.
You can google for critical induction. You will see that with smaller induction you will need more current.
Wait for the others to react. It will work without bleeder but like i said better use one will also discharge the caps after switching off.
Sincere greetings, edward
 
#2,135
Hey dwjames,

If you have two chokes or trannies with all the laminations facing the same way(for the OCD in us, or for those who do it properly,CDO) it can multiply the magnetic field and cause noise in the 50/100hz band(60/120 for the US) in the remainder of the circuit, by turning one 90' to the other this can be minimised. Having a flux band around the choke helps, also potting it in a ferrous/permeable material assists in this as well.

Thanks for all the powersupply inspiration guys, excellent to watch!

Chuz,

Drew.
 
#2,137
Hello,
The photo in the link also shows how to wire the 2 coils in series.
Finding out how to orientate the transformer and the 2 chokes would be that difficult using the technique described.
It would be wise to let the radiation of the last choke not going towards the circuit or the output transformers.
I am in the metal '' business '' so not that difficult to make a cap ( can even try to pot them).
If there is some current in the power transformer it will be easy to create a magnetic field. Like you can read in the link the first choke will have strong field too.
Move the parts around, without creating a short circuit and you will find the best location. Then take a photo and post it here.

Sincere greetings, Edward
 
#2,139
G600 said:
Rick,
Have you progressed in your calculations ?
Note that 20mA is recommanded for a 100mA step, I guess we are far from that with a DAC deck (Doede wrote one deck draws +-100mA).
Click to expand...
From my understanding, each digital 3.3v circuit on each dac deck draw around 20mA and the analog 8v circuits each draw around 40mA


Thanks for the tips with the power supply layout guys 🙂 I've been doing a bit more reading up and I think I may go for point to point wiring rather than using stripboard as then I can get the components REAL close (like soldering the rectifiers direct to the input of the first choke) and also put a nice star earth in.
 
#2,140
Hello,
So far i always preferred shunts. The late Allen Wright did tell that the way to go is choke input with a shunt. The choke should be the same seize or bigger as the power transformer. Just repeating his words.
Did find a nice link but dont know how to copy this link. Will do this when using my own pc at home.
Sincere greetings, edward
 
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