6K add on C buss

[xmax]

Does anybody have the pin outs for the 10 way ribbon connectors for the 6K C buss,
It looks like SSL added some long skinny pcb's under the bucket backplane. The
manuals I have state it is on S3E but it does not seem to be the case....

[xmax]

Found it! S125E
pin 2 C Left
pin 5 C Right

everything else is 0v

[waltzingbear]

and its always slightly noisier than A or B buss.

Alan

[xmax]

In the beginning SSL had the C-buss mixed in with the logic S3E ribbon, I imagine they did this to
improve the noise, I wonder if the early ones gave C a bad reputation, In this case with the 990
summing C was quieter than A which is now a stock 4K.

[waltzingbear]

could you expand your comments?

the 6K board I am familiar with has a noisier, not by much, buss noise on C.
don't know which cable they used, mostly ac related noise.

990 summing? is this a summing buss with a 990 summing amp substituted?
would seem to be almost coals to newcastle as the input is very similar, but not quite. 

[xmax]

If you look in mainframe wiring section of the manual it shows S3E ribbon as the summing busses to feed the hex buss C amplifier (5&6).
At some point they added a small thin pcb that ran under the S3E area of the bucket mother board and moved the C-buss  L and R from S3E to this small added on pcb
(on the bucket backplane pcb bottom). The desk I was working on has API and 990 opamps on the B and C busses as mix/master amps.

[aaladhamy]

hey there!

My C bus on my 600 has been giving me some bad problems... the R channel intermittently gets very noisey and swooshy which stops when I either touch a capacitor on it, or tap the cables attached to it. Does anyone have the schematics for it? i want to recap and replace all the parts... Also its strange that the final output is determined by this bus as well... even if i have nothing sent to the C and it is off the noise still comes through the stereo out...

thanks for any help!

[xmax]

Check the technical documents section.

[aaladhamy]

can't find it on there! am i missing something? cheers!