HELP! Central Station & Buss Comp won't work together??

[BusyBoxSt7]

I have a presonus central station. Here's the signal chain during mixing...

-aurora converters, 16 ch. out to ->
-roll music folcrom passive summing device, 2 ch out to ->
-mic preamp (can be API 3124, Chandler TG2, etc, doesn't matter), 2 ch out to ->
-klark teknik dn504 plus compressor, 2 ch out to ->
-presonus central station.

THE PROBLEM
When I run this, I show full meter activity on mic pre, compressor, and the central station, BUT ALMOST NOTHING COMES OUT THE SPEAKERS. It's almost inaudible until the last 5% of the volume knob, then it suddenly jumps a little louder (while sounding terribly grainy) AND the meters on the central station DROP about an inch as the volume picks up.

WHAT'S ALREADY BEEN TESTED
1) I've run the exact chain and sent the output from the compressor back into pro tools. It has healthy volume and doesn't sound all grainy/crunchy).
2) I've run the same setup without the comp (preamps straight to the compressor) and it runs fine
-in other words, all the cabling has been tested + the individual hardware pieces.

ANYONE HAVE A CLUE?
currently waiting on phone for presonus tech support, 30 minutes to get the guy on the phone, of no help. his supervisor says it's not designed to take signal from a compressor which would not be true line level signal (what?).

If you use a buss comp, please enlighten me as to where you put this in your chain. Thanks.

[ott0bot]

That's weird...if it comes into PT without distortion...it's odd that it wouldn't work in the central station.

Is it possible the output of the bus comp is overloading the central station?

Compare the level coming out of the mic pre into PT's to the level coming out of the bus comp into pro tools. Maybe it just can't handle the extra dB's.

If the signal level is close enough and still only works with the mic pre, and not the bus comp then it's got to be a cabling or patchbay issue...

Are you are running a female XLR to male TRS out of the bus comp into the Central Station's analog inputs? If so are you sure the cable and the bus comp are have the proper pin out to connect to the trs input of the Central Station?

Are you using a patch bay for routing? If so....maybe one of the patch bay inputs is not making proper contact?

Maybe take the patchbay out of the equation, and try direct cabling?

[BusyBoxSt7]

according to the levels recorded in PT, there is no significant difference between the compressor and the preamp (neither is near clipping in PT), and it doesn't matter what output volume i adjust the comp too (granted it sounds more and more distorted as you turn it up, but it never acts normal at lower output volumes)...

cabling is all the same cables in use w/ the preamp, and same cabling used when recording the compressor back into PT so I don't think it's that.

there is no patchbay, it's already direct wired

pinout wise, it's the same cable i use coming from the mic pre to the central station and it works fine in that scenario. here's the pinouts for each -
COMP ->
output (says unbalanced later below)
unbalanced 1gnd 2gnd 3hot
balanced 1gnd 2cold 3hot

unbalanced
minimum load impedance 600 ohms
source impedance <60>[/b]
ins and outs = T hot (pin 1), R cold (2), S ground (3)
TRS1&2
Type 1&#8260;4? TRS Passive-Balanced
input impedance 2K-5K Ohm (Speaker load and Trim level dependent)


VERDICT
Looks like it's the pinout... i'm not too ohm savvy, but guessing it's just the pinout

[TapeOpLarry]

Take the compressor out of the chain and I bet it all works fine. The audio is likely shunting to ground because of the klark teknik pin 3 hot situation.

[BusyBoxSt7]

haha.. it's always worked fine straight off the folcrom/pres... i was just bummed that i couldn't get the compressor to work.

looks like i just need to order some adapter cables.

[TapeOpLarry]

You could rewire inside the KT box. Should be very easy to reverse the pins 2/3

[Dakota]

Pesky pin 3 hot thing, indeed. Alternate to rewiring the KT comp ins and outs is resoldering your cables to and from it to flip tip and ring on one end. Then label them as "flip" cables. Handy to have in any case.