XMOS-based Asynchronous USB to I2S interface

Does anybody on this thread know how much current the 3.3V isolated i2s output on the WaveIO is using?

Don't know if this will help, from post #1672 ( http://www.diyaudio.com/forums/digital-source/188902-xmos-based-asynchronous-usb-i2s-interface-168.html#post3427801)

The WaveIO card usually needs up to 380mA when working at 24/192. My previous estimations were all wrong and I'm sorry about that. Anyway I'm not upset (too hard) about it as it's better to have some extra current for "just in case" situations rather than be on the opposite end (like when you will power your WaveIO board from the USB bus). Edit: forgot about NVE isolator. The datasheet is located here and at pages 5 and 6 you will see the infos you need (look for Idd2 of IL715 part). I say that 20mAmps @ 3.3Vdc will do the trick.

Kind regards,
Lucian
 
Confirmed, it works!

So, after trying to interpret the CS8420 datasheet, I think I have a way to get I2S into the DCX. I haven’t inspected the board yet to see how feasible this will be, but it looks reasonable. Hopefully someone who better understands the ASRC is able to deny or confirm this information.

Remove TR1 and R15
Isolate/lift pins 12 and 14
Jumper pins 2 and 3 and 5
Jumper pins 4 and 23
Jumper pins 27 and 28
Jumper pins 19 and 22
Isolate pin 20 and tie to pin 23
Connect I2S leads from XMOS:
ILRCK = pin 12
ISCLK = pin 13
SDIN = pin 14
 
Hi together,
after update to "MAV" ... no more 384 :(
 

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I am new to WaveIO and am running the isolated SPDIF output to my TP Buffalo 3 DAC, just to get a first impression. SQ is already impressive, but I want to connect it via I2S now.
The question is what is preferred: the isolated or non-isolated I2S connection? I am sure others have compared these two options already. So perhaps I don’t have to reinvent the wheel.
It could be that this issue is already covered somewhere in this long thread.
Any thoughts?

Peter
 
I got my WAVE IO board in the mail last month from Lorien, but haven't had a chance to try it out yet. Still gathering connector and chassis bits, and reading the thread. Although I hear it is not an optimum use of the WAVE, I want to use the isolated SPDIF outputs to drive my Buffalo II DAC through its sole BNC input connector. (There's no room in the DAC chassis to implement switching alternatives.)

I have two questions. 1) should the WAVE board be grounded to my aluminum Hammond chassis through the one standoff hole on the WAVE that is grounded?
2) which pad is which, on the pair of WAVE's SPDIF isolated outputs? One is a square pad, one is circular (if there is a convention here, I plead ignorance. Actually I don't have to plead it, I just demonstrated it!)

I'm going to use an insulated Neutrik BNC connector on the output. Thinking about using a Neutrik USB connector on the input, instead of the BRD connector that comes soldered to the WAVE. Any thoughts on the latter would be appreciated, especially if using a short cable connection to the header on the board threatens to introduce more jitter, or to otherwise compromise performance of Lorien's beautiful piece of work.

Any advice would be appreciated.

Thanks in advance.

Larry W.,
Seattle area
 
Lucian: Can you give us an update on the planned availability of "WaveIO with Daughterboard" or new "WaveIO Note". My current WaveIO is one from just before firmware update via s/w download was possible, and I really want to move up to having a USB input that can accept 352.4/384.
Hope all is going well for you there in Romania.
Regards,
Alex Crespi
 
Is there a way to use something like this for reading a USB thumb drive in order to drive a DAC?
Unfortunately WaveIO can't act like a USB Host only peripheral device... I'm sorry about that!

I got my WAVE IO board in the mail last month from Lorien, but haven't had a chance to try it out yet. Still gathering connector and chassis bits, and reading the thread. Although I hear it is not an optimum use of the WAVE, I want to use the isolated SPDIF outputs to drive my Buffalo II DAC through its sole BNC input connector. (There's no room in the DAC chassis to implement switching alternatives.)

I have two questions. 1) should the WAVE board be grounded to my aluminum Hammond chassis through the one standoff hole on the WAVE that is grounded?
2) which pad is which, on the pair of WAVE's SPDIF isolated outputs? One is a square pad, one is circular (if there is a convention here, I plead ignorance. Actually I don't have to plead it, I just demonstrated it!)

I'm going to use an insulated Neutrik BNC connector on the output. Thinking about using a Neutrik USB connector on the input, instead of the BRD connector that comes soldered to the WAVE. Any thoughts on the latter would be appreciated, especially if using a short cable connection to the header on the board threatens to introduce more jitter, or to otherwise compromise performance of Lorien's beautiful piece of work.

Any advice would be appreciated.

Thanks in advance.

Larry W.,
Seattle area
Hello Larry! @ J11, the SPDIF outputs are as follow: the squared pad is the "hot" signal while the round one is for returning currents (cable's shield). There's no direct connection between this round pad and the rest of WaveIO's ground planes. One small advice: please try to focus on a small diameter 75R coaxial cable because the pads are quite small compared with what it has to be there.
On the J10 output things looks similar: square pad is for hot signal while the round is for GND. This time the GND of J10 is actually connected to the rest of WaveIO's ground planes so be careful on this!
As for the chassis mount, please note that the single mounting hole connected to the ground planes is H4 (located on the lower-right corner of the board) while the rest of them are floating!
If you don't want for WaveIO to be directly connected to your chassis be careful to isolate the on-board USB connector's shield from it otherwise there are chances for ESD discharges to blow up a part on the WaveIO board... it's about ferrite bead FB4 which is connecting the USB shield to WaveIO's ground planes. It happened before so I'll go with Neutrik :)

Lucian: Can you give us an update on the planned availability of "WaveIO with Daughterboard" or new "WaveIO Note". My current WaveIO is one from just before firmware update via s/w download was possible, and I really want to move up to having a USB input that can accept 352.4/384.
Hope all is going well for you there in Romania.
Regards,
Alex Crespi
Hello Alex, we can discuss privately the update for your card if you want! I've done it before and I can do it for you too! As for the DB or note, things are not looking promising. Tomorrow I'll go and take few measures for Note and actual WaveIO away from this noisy and dirty city I'm living in. "Going well" could be considered a forced expression but I guess it could be worse than that! :)
Kind regards,
L
 
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Thank you, Lorien! I'm still left wondering, however, whether there is any advantage to grounding the WAVE board to a metal chassis, in terms of shielding, I mean, or possible ground loops. If I use Neutrik connectors on the input and output (both isolated from any direct connection with the aluminum case), do I want to ground the WAVE board through that one mounting screw to the case, or not? I know this probably sounds impossibly naive, but grounding issues have confused me for more than 35 years of constructing stuff. And digital devices are pretty much totally new territory for me. :eek:

Larry W.
Seattle area
 
Hi folks,

I've a couple of Wave boards - one feeding I2S to my buffalo II, the other I use in a USB to spdif convertor. On the latter setup I'm using a single co-ax connection but I'd now like to add an optical TOSlink output.

I've bought a Sharp emitter but I confess I've not much of a clue how to connect this. It appears that the emitter needs a TTL input and then outputs optical spdif. I looked at the data sheet plus some advice from the good people over on Pink Fish and I need a couple of caps across the supply and signal inputs but is that all I need to do?

Help appreciated but please be gentle - I'm a numpty with this stuff...
 
Hi folks,

I've a couple of Wave boards - one feeding I2S to my buffalo II, the other I use in a USB to spdif convertor. On the latter setup I'm using a single co-ax connection but I'd now like to add an optical TOSlink output.

I've bought a Sharp emitter but I confess I've not much of a clue how to connect this. It appears that the emitter needs a TTL input and then outputs optical spdif. I looked at the data sheet plus some advice from the good people over on Pink Fish and I need a couple of caps across the supply and signal inputs but is that all I need to do?

Help appreciated but please be gentle - I'm a numpty with this stuff...

+ add a small 1 uH choke too, I think.
 
Waiting for my board, and have several questions that I haven't found answered.

1. There was recently mentioned connecting the shield to chassis. My chassis is acrylic, with an internal aluminum enclosure around the AC section. I have that internal enclosure grounded to the AC in. My plan was to not attach the shield, but I could if this is recommended. If I should ground it, do I take the ground from the "chassis" ground, or do I use the ground output from the power supply to the card?

2. Ideally, I'd like to use a data only wire for the USB. Does the card require any power over the USB to "handshake", or will just the two data lines work?

3. This is related back to the ground issue. I may need to use a chassis mount USB port, and wire to the card. I think the answers to 1 and 2 will tell me what I need to know about how many connections I need to make for best performance, but I would appreciate any feedback from others.

4. The other option for me (this due to needing to get the uFL connectors to within 10CM cable reach of my BIIIse) would be to mount the wave vertically, (at 90º to the other cards), which would allow me to just use the board mounted USB port. I'm totally clueless about higher frequency practices, and wonder if doing this is generally a bad idea in terms of induced ground planes (or whatever). Opinions?