• We would like to remind our members that this is a privately owned, run and supported forum. You are here at the invitation and discretion of the owners. As such, rules and standards of conduct will be applied that help keep this forum functioning as the owners desire. These include, but are not limited to, removing content and even access to the forum.

    Please give yourself a refresher on the forum rules you agreed to follow when you signed up.

FAS Link cable run works for FC-6 but not FC-12

Chad Beattie

Inspired
Two Axe-Fx rigs at practice last night. I have an FC-12, the other guy an FC-6. The sound guys patched our FC's through the xlr snake back to our Axe-Fx's. My FC-12 booted up, but was stuck at the screen saying Firmware 1.09. I unplugged it and plugged back in, same issue. So I ran a new cable direct from my FC to the Axe-Fx and all was well. But after practice, I thought I would try it again. I plugged back into the xlr patched through the snake, and same issue. I then plugged the same cable into the other guy's FC-6. That worked fine.

Just wondering if the FC-12 has more stringent run length requirements or anything like that. I assume it uses more power. Anyway, just thought I would ask. Tomorrow we will run a new set of cables through the snake on different ports and see if the issue still occurs.

Thanks
 

Chad Beattie

Inspired
what's the total cable run you have going on?
I will have to verify Saturday. The sound guy said it should be less than 100ft. Wasn’t sure if anyone else was doing this either and if their are specific run lengths that need to be adhered to for the 6 vs 12. I do have several XLRs I can chain together at home and see if I can replicate the issue. Also, I’m not ruling out either that the run may have issues, but maybe the 6 isn’t affected as much.

Thanks
 

chris

Legend!
I will have to verify Saturday. The sound guy said it should be less than 100ft. Wasn’t sure if anyone else was doing this either and if their are specific run lengths that need to be adhered to for the 6 vs 12. I do have several XLRs I can chain together at home and see if I can replicate the issue. Also, I’m not ruling out either that the run may have issues, but maybe the 6 isn’t affected as much.

Thanks
it would make sense that the 12 needs a bit more power than the 6, but i don't know that for sure. i think 100 feet might be pushing it, but i don't remember the exact spec length. Cliff stated it at some point on the forum i believe.

the fact that it worked directly from the Axe sorta verifies the snake could be introducing some sort of issue. any snakes i've seen usually have very thin wire since so many are stranded together. might be that too.
 

Rex

Legend!
FASLink has been tested with the FCs out to 100 feet. If the connections are good, that distance shouldn’t be an issue.
 

simonp54

Veteran
Many possible problems could be here. Try another “channel” on the snake.
Eg.. you said it powered up... but didn’t do anything, that could be another core in the channel broken.
Eg. It could be the “cores” aren’t big enough and the voltage presented is marginal to the FC.
Eg. Dodgy connector issues/aka broken.
Etc Etc
 

FractalAudio

Administrator
Fractal Audio Systems
Moderator
Two Axe-Fx rigs at practice last night. I have an FC-12, the other guy an FC-6. The sound guys patched our FC's through the xlr snake back to our Axe-Fx's. My FC-12 booted up, but was stuck at the screen saying Firmware 1.09. I unplugged it and plugged back in, same issue. So I ran a new cable direct from my FC to the Axe-Fx and all was well. But after practice, I thought I would try it again. I plugged back into the xlr patched through the snake, and same issue. I then plugged the same cable into the other guy's FC-6. That worked fine.

Just wondering if the FC-12 has more stringent run length requirements or anything like that. I assume it uses more power. Anyway, just thought I would ask. Tomorrow we will run a new set of cables through the snake on different ports and see if the issue still occurs.

Thanks
The FC-12 uses more power because it has more LCDs. If the cable resistance is too high than there will be excessive voltage drop which could cause booting issues and other problems.

Using a cable snake is not recommended because the conductor gauge is small and the resistance will be high. We recommend a good quality dedicated XLR cable.
 

Rich G.

Veteran
The FC-12 uses more power because it has more LCDs. If the cable resistance is too high than there will be excessive voltage drop which could cause booting issues and other problems.

Using a cable snake is not recommended because the conductor gauge is small and the resistance will be high. We recommend a good quality dedicated XLR cable.
The wire in cable snakes is typically stranded 22 or 24 AWG which has a resistance of approximately 15 or 25 ohms per 1000 ft respectively (Source). What is maximum voltage drop the FC-12 can withstand?
 

Rex

Legend!
I’ve used 100 feet of dedicated XLR cable to connect both an FC-6 and FC-12. No problem.
 

Chad Beattie

Inspired
Thanks for all the replies. We did try different channel. FC would boot all the way, LED's not as bright, but wouldn't respond to any switches. If I remember I will see if I can grab the details of the snake (not sure if the model number is on the end or not). THen at least have more specifics on the length, resistance, etc... for reference.
 

FractalAudio

Administrator
Fractal Audio Systems
Moderator
Thanks for all the replies. We did try different channel. FC would boot all the way, LED's not as bright, but wouldn't respond to any switches. If I remember I will see if I can grab the details of the snake (not sure if the model number is on the end or not). THen at least have more specifics on the length, resistance, etc... for reference.
The dim LEDs are an indication that there is excessive voltage drop on the cable.
 

Joe Bfstplk

Veteran
The dim LEDs are an indication that there is excessive voltage drop on the cable.
Yup. If the 12 draws more current, and it's a long run, it could drop enough voltage where the FC's processor chips won't run, even if some other functions look like they are trying to work (backlights for LCD displays, for example) while a 6 would work ok....
 

FractalAudio

Administrator
Fractal Audio Systems
Moderator
The FC rated voltage is 9-12V but should work down to about 7V. If the snake is 100 ft. of 24 gauge wire then that would put you right at 7V. The FC-12 draws about 1A so Vdrop = 0.025 ohms/ft * 100 ft * 2 conductors * 1A = 5V drop. This is assuming the shield drain has the same resistance as the conductors.

So, yeah, 100 ft snake is too long for an FC-12.
 

Joe Bfstplk

Veteran
The FC rated voltage is 9-12V but should work down to about 7V. If the snake is 100 ft. of 24 gauge wire then that would put you right at 7V. The FC-12 draws about 1A so Vdrop = 0.025 ohms/ft * 100 ft * 2 conductors * 1A = 5V drop. This is assuming the shield drain has the same resistance as the conductors.

So, yeah, 100 ft snake is too long for an FC-12.
Also assumes zero or near-zero resistance at the connections.

Throw in a dirty connector, and even a 50' or 20' cable could fail to peoperly run it.
 
Top Bottom