Channel passing audio without fader

[Tonemiester]

So I have a channel that passes audio to the master bus regardless of the fader position or with the fader disconnected. Any ideas would be appreciated.

Thanks,
Mike

[Dave Dicson]

If it is an SSL 4K console. Sounds like it might be the "13" VCA card. Swap it another channel and see if the problem moves. It is the smallest PC board on the module. It might be the logic card at the bottom of the module, under the Total Recall card, if there is one.

[Tonemiester]

It is a 4K. I will check that. Thanks Dave.

[Dave Dicson]

I should have mentioned, if you go into "VCA to Meters Mode", does the VU meter move with fader? No audio. If you are using the SSL computer, does the fader move on the screen?

[Tonemiester]

Dave, I will check that. I dont use the computer even though it works. I use the bypass so I can use the groups. Thanks again!

Mike

[Dave Dicson]

Ok, Mike. VCA to Meters will still work without a computer. We have 2 4K's without computers and 1 with a working computer. Good luck.

[Pinebox]

Sometimes the little ribbon jumper on the bottom of the 611 below the edge connector gets frayed and causes havoc with the fader level.

[Tonemiester]

Will check. Thanks.

[Dave Dicson]

So far, I have never had this happen yet on the 6 SSL's I've dealt with.

[horizonsound]

I've seen this a few times, and the cause was on the logic card (E12). BC212 transistors failing and not pulling down the status line.
The G series somewhat corrected this by using a -25V low logic rail.

Anthony.

[Dave Dicson]

Anthony, I've never heard of a -25V logic rail. Just +20V. & - 20V, Audio & 11V. logic.

[Tonemiester]

So it wasn't the "13" card. I can replace the transisters. Can you tell me which ones?

Thanks,
Mike

[Tonemiester]

So to clarify, CH 13 passes audio regardless of the fader position. When I swap 13 and 14 the problem follows 13 (now in slot 14) however slot 13 does NOT pass audio. When I select global Replay they both pass audio through the little faders.

[horizonsound]

The -25V is generated on each G series logic card (6082293) using a charge pump.

Anthony.

[horizonsound]

Sound like you have some multiple issues going on there. Possibly with Ch 14 as well.

Check and reseat the cabling to the fader bus card. I've seen instances of where these drop out VCA signal, usually as a result of something being spilled on the console.
Check the patch bay. Depending on the age of your console, the normalling in rows C>D and J>K might not be making good contact.

Anthony.