M2TECH Hiface USB->SPDIF 24/192Khz asynch

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Jump to Latest
merlin el mago

merlin el mago

Member
Joined 2009
Paid Member
GuidoR said:
Modding HiFace: how to

The board is very small, so only limited mods are possible.
Here the most important ones.
Taking out I2S: the points are on the following resistors:
MCLK -> R3
SCLK -> R5
LRCK -> R6
SDATA -> R7
In theory, it could be better to steal the signal upstream of the res, in case of long wires, downstream in case of short ones.
The "up" is the side near the DIT for R5 and R6, the opposite for R3 and R7.
In fact, due to the extremely small dimension of the 47R res (0603) is not advisable to attach wires directly on them, the risk of burning them (as I did :() is very high. (you can see from the pics that I replaced the 0603 with 0805, but due to the limited space one has to be mounted on edge:eek:).
DO NOT REMOVE THOSE RESISTORS!!!!
My solution, after some disasters :(, has been oriented to the better "mechanical" solution, in order to avoid any stress to the very fragile pads. Following the tracks from the resistors, you can see four vias that are connected, the other side, to the Xilinx chip (the one with the big green dot).
I ran copper wires (0,35mm - AWG 27), duly bent and tinned, applied some flux, lined them up on the legs of the chip and just a tip of a soldering iron - a magnifier is a must. The attentive reader can note that the connexions are mixed - upstream and downstream: it works just the same.
You can steal the ground connection from the second uninsulated pad on the side of the board (near the square one).

Replacing PS: the HiFace is fed by USB, so we can isolate the V input.
To make the change reversible, I disconnected the Vin pin by only lifting them, and connecting an insulated wire. The wire is fixed with a tie-wrap to improve the mech (and to avoid stress to the pads).

On the pics I have evidenced in red the vias and the contacts.

Enjoy (I did!!) :D:D
Click to expand...

There is other hole to connect the ground?
 

Attachments

  • pic%201.JPG
    pic%201.JPG
    141.8 KB · Views: 308
Valeriano

Valeriano

Member
Joined 2006
merlin el mago said:
Ciao Vale,

Sto cercando altro posto per connettare il GND / I'm looking for other hole to connect the GDN

Grazie/thanks
Felipe
Click to expand...

Hi Merlin,

ok! I was wondering why you need a different pad.. anyway, I have in front of me the hiface open with a DMM.. I can't find a different hole of the same size connected to GND, you may use the GND from the USB connector, assuming you have the pen oriented like the one in the picture GND is the lower PIN. Alternatively there some smaller holes (vias) which I don't recommend to use, very easy to damage. let me know if this helps.

ciao
Vale
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Top Bottom