Here is the schematic. As you can see each channel is identical.

Also please note many are using this module without any issues at all. Some who initially had a problem resolved it pretty easily (by correctly converting TTL to consumer level SPDIF) . As long as you are providing clean consumer SPDIF or AES input at each channel it will work exactly as designed.

Cheers!
Russ

just one specific q:
when the dac is told to change s/pdif input does it connect to that spesific inputs both neg and positiv leg or do the inputs share minus in some way in the dac chip?
i.e paired in e.g 1&3 and 2&4


addition:
haven´t noticed before but the IC on the s/pdif board has separate plus and minus inputs, but only plus outputs
what does this chip do?

best
Leif

Edited by user Monday, May 7, 2012 10:33:04 AM(UTC)  | Reason: Not specified

hello?
did the list you wanted tell you anything at all?
is the s/pdif input switching kept separate on both positive and negative signal in the whole chain from pcb input to dac inputs? clear answer pls?

best
Leif

The only thing that can be interpreted as having a negative (return) signal would be the connection to the input transformer primaries. This is because they are normally not DC(galvanic) coupled to GND and are simply an AC signal.

hello folks
got my dac back from my technician friend, which didn´t really find anything wrong, but he had discovered a few "issues" which put me on a new /untried track:
the dac responded with solid locks when tampering with the digital IO pins on the BIII board where the sidecar is soldered "piggyback"
wasn´t sure whether is was the capasitance of my body or tool that did it, but decided to solder som ceramic caps 120pF across D1-D4 to respective gnd
that helped but not enough
fiddled around with croc clips to gnd and one combo did the trick:
all s/pdif rca connectors minus were soldered together with a "shield braid" and hooked up to LCH xlr connectors chassis which in turn is in contact with rear alu plate
in addition gnd wire from LCH SE output rca chassis minus were hooked up to same spot on XLR
i.e Legato gnd was led to same spot as s/pdif connectors´ s minus on rear plate
now all combos seems stable with or without other sources hooked up or powered on
will let it run for a few more days to be sure, but so far, so good

best
Leif

it is stable!
Russ/Brian; what about just implementing those ceramic caps on the BIII inputs to be sure?
or can they cause harm in any way?
best
Leif

Leif,

can you post some scematics of what you did to solve the problem?
I have the same problems but I decided to just leave it and not to frustrate myself anymore.
I disconnected the COAX and BNC inputs and leave the S/Pdif 4:1 for what it is.
I only use Toslink and will move on to USB in the future (next winter).
But it's a little dissapointment in a great experience that I have not managed to solve this issue...

The last thing I tried is connecting the Toslink directly to the DAC and cut away the interconnection of the ribbon cable between the S/Pdif board and the Sidecar but I still experience locking problems when all connected.

jordo

Leif,

My response is purely practical.

What you propose is not a good idea because those caps present the source with a short at high frequencies. Your particular sources may or may not be adversely effected , but some could actually be permanently damaged that way.

Beside all that - you are the *only* one I know of who had your particular issue. :)

The only other issue I know of was solved quite logically and conventionally with appropriate level shifting.

I am not about suggest people do something that could actually harm things.

There are many happy people using the Sidecar with spdif4 without any issues at all. There is only one thing to remember. The SPDIF4 board is not meant to accept TTL level inputs. :)

Cheers!
Russ

Edited by user Monday, May 28, 2012 12:53:30 PM(UTC)  | Reason: Not specified

I was just asking to draw out his solution.
But never mind. I blew my Toslink channel on the S/Pdif board when trying the last.

Jordo

This is from Leon's guide

"In the table R<Z> is the resistor R1 to R4 on the board. These resistors are linked to their corresponding
input positions (INA to IND). See also the table: Lay-out of S/PDIF-4 Input Board V1.1. So if you want to
use the (TTL level) Toslink module on position C, you change the value of resistor R3 to 10KΩ."

Is it right/wrong? Or are there other things needed?

Allan

PS I know this is an old thread, but still relevant to me..

Edited by user Saturday, August 25, 2012 7:22:51 AM(UTC)  | Reason: Not specified