I2S to Caiman help please.

[DaveK]

Hi Guys,
I guess this plea is aimed at Stan (the man ;) ) and/or leo.
On another forum I have got involved in a GB for an Amanero board - see here for some info on the Amanero board if you are not already aware: -

http://hifiduino.wordpress.com/2012/11/02/amanero-usb-synchronous-reclocking/

This link is not specific to my question but hopefully will give you some idea of the Amanero board. I am aware that this board is capable of 'doing' higher res files than is my 7520 but at this stage that does not worry me (and may not ever :) ). What I am not aware of is how to link the I2S signal out of the Amanero into the 7250. If Stan or leo can give me some simple guidance as to if and how this can be achieved I'd be very grateful. I have no intention or ability to carry out this work myself but my builder is technically and solder-wise very capable so I have no worries on that score unless it is virtually impossible.
So, can anyone offer any help please?
TIA,
Dave.

[StanleyB]

Best of luck with that Dave. I myself would never attempt such a mod. The I2S inputs to the DAC chip would have to be cut and some sort of socket, like a RJ45 socket would have to be wired into the cut tracks leading to the DAC chip. Will it be worth it? I seriously doubt that.

[lemon]

I have the same thought with the Davek.
Stanley, this will be a marvelous capability for this dac, if the I2S mode is only extra on it, without any disadvantage to other s/pdif inputs.

From the datasheet of WM8716, I see that there are four operation modes: Normal Mode, Differential Mode, 8X Mode and Software Mode.
I suppose that the Differential and Software Modes are cancelled. Which is operation mode of Caiman or mine (7520 to Caiman mods)?
The datasheet says that for the I2S only Normal and Differential Modes are appropriate.

(Sorry for my english)

[leo]

It should be possible but risky , as Stan already mentioned it requires some bodging. If you run your caiman with passive output i'd be tempted to knock a wm8716 up on one of those converter boards and use that with the Amanero(lack of any added active output stage makes the knock up simpler) It would save any risk buggering your caiman up. I recently did this with a pcm5102 and tapped into a QA550 sd card players i2s lines

[StanleyB]

The Bushmaster would be a far better candidate for I2S. I put a resistor in each of the four I2S lines. An enterprising DIYer could easily make use of that to solder some link wires into the I2S data bus. No need to cut tracks then.

[leo]

Padding resistors on the pcb lines would certainly make this mod far more easier to try. Get a BM Dave and give it a go ;) be easier than bodging the caiman or trying to knock something up on a piece of vero and converter board

[DaveK]

Thanks Stan and leo,
I have been tempted by the Bushmaster since Stan first announced his intentions so I am not against buying one in principal, rather the reverse :) , but £180 for another DAC (I already have 3) is expenditure I could do without. On the other hand, getting someone like Jimmy at Tirna to attempt the necessary micro soldering on my 7520 is gonna be risky and probably ain't gonna come cheap either - oh, decisions, decisions :lol: ;) , something more to mull over.
Dave.

[StanleyB]

Thanks Stan and leo,
I have been tempted by the Bushmaster since Stan first announced his intentions so I am not against buying one in principal, rather the reverse :) , but £180 for another DAC (I already have 3) is expenditure I could do without.
Good call. It's not like chasing the dragon after all..

[Stratmangler]

A good starting point might be a DAC already designed with I2S operation in mind

http://puriteaudio.co.uk/images/EvoDac19232_XL.jpg

The I2S is via a RJ45 connection on the rear panel.

[leo]

As you can see the tracks that need cutting in the 7520 are quite thin, it would be a very delicate job. You may get reliability problems.

http://i273.photobucket.com/albums/jj220/kingbusoms/WM8716.jpg

Running thin wire to padding resistors would be a lot easier than tapping into thin tracks . Much less chance of lifting that thin copper.
If it wasn't so risky with the 7520 I'd have tried it and added some pics :)