SSL 4000 E/G VCA Group Faders Problem

[nycsudio1]

Hi there,

I own a SSL 4000 E/G console with VCA faders. I bought the console about three years ago and although everything works, there's one problem that I haven't been able to figure out since the day I bought this console.

None of the 40 vca faders will assign to any of the 8  groups.

If I set channels 1-8 to VCA 1 (or any other VCA group), nothing happens. This function is completely inactive.

The computer and tr are working fine and every channel works fine. Unfortunately I cannot find anywhere in the books where to look for this problem.

I even brought a couple of techs to check it out but so far no luck.

I appreciate any tips or suggestions.

Thanks.

[PelleG]

Yo,

The thumbwheels are - if not modded - hardwired. Means no failing logic circuits.
So my guess is you should look for any quirks at the VCA masters. Or, along the path of the VCA masters control voltages. If the computer is stuck controlling the masters at 0db it will appear as nothing happens. Check the mutes also.

There's a DIY 50 pin IDC plug for bypassing the computer. Google and you find it. It just routes out to in so you can run without computer. Stick one of these in the VCA bank under the patch.
If it's still doesn't work it smells like a mod.

[sintech]

Here's a pic of the computer bypass, 50 way IDC and some 10 way ribbon, easy to DIY as Pelle suggests.




Does the master fader function ok? it also passes through this 50 way.

[nycsudio1]

Guys, thanks a lot for the replies.

I am going to look for the bypass idc and will also check voltages.

The master fader works fine, automation is also working fine. The only issue I have with this board is assigning faders to groups.

[waltzingbear]

sounds like a failure in the assign from the switches, don't remember if it uses just a 5V logic line to drive logic elsewhere or direct control of assignment. but follow those things thru the logic. Start at the thumbwheel and then go up stream from there until you don't get the signal following the switch you want.
 
Alan

[PelleG]

No logic. Hardwired.

[sintech]

I'd re-chip the quad op-amps, and change the 2 caps on the 82E20 card, just to rule that out. voltages 0-8 are made on this card.

[nycsudio1]

Thanks again for all the help. I am gathering all the info that I can and will go over the console this weekend after our sessions are out of the way.

The center section was recapped three or 4 years ago, but I will definitely look at the caps in the 82E20

Also, could it be that when the 82e20 was recapped one or more of the ribbon cables were connected to the wrong plug? I need to get the books with the info on this card as I can't find this specific page in my books.

If anyone has any other tips please feel free to share.

Many thanks.

[PelleG]

I would check, with a multimeter.

In this order:
1. Between GND and fader send (any of the 8 VCA masters on the VCA / Master IDC under the patch. )
2. Between GND and any VCA thumbwheel pin (remove a channel fader somewhere to access thumbwheel voltages)

Fader top should be 0V, fader bottom should be 5V, mute should be around 7.5V.
If all these points clears the test ... I'm ... clueless.

My guess is the computer.
I can't remember how the computer setup acts. But it should be aware of where the VCA masters are. Is there a setup page in there which tells the channel layout?

/P

[nycsudio1]

I will definitely test the voltages this weekend.

Thanks for the tip.

I would check, with a multimeter.

In this order:
1. Between GND and fader send (any of the 8 VCA masters on the VCA / Master IDC under the patch. )
2. Between GND and any VCA thumbwheel pin (remove a channel fader somewhere to access thumbwheel voltages)

Fader top should be 0V, fader bottom should be 5V, mute should be around 7.5V.
If all these points clears the test ... I'm ... clueless.

My guess is the computer.
I can't remember how the computer setup acts. But it should be aware of where the VCA masters are. Is there a setup page in there which tells the channel layout?

/P

[waltzingbear]

I'm assuming you already checked the readout for the channels on the VDU?

in the TES! section if I recall correctly.

Alan

[nycsudio1]

No I haven't and I am not familiar with this procedure. I will definitely look into it this weekend. Meantime, if there's any other suggestions please feel free to send them my way. Thanks.

I'm assuming you already checked the readout for the channels on the VDU?

in the TES! section if I recall correctly.

Alan

[nycsudio1]

Here's what I found so far:

Fader voltage tests:

VCA Group Fader down = 0.085 vdc
VCA Group Fader Up = 0 vdc

VCA Mix Fader down = 4.927 vdc
VCA Mix Fader up = 0 Vdc

It appears that there's no voltage in the group faders.

Also, when checking the cables and connections I noticed that there is one ribbon cable coming from the computer numbered S95E events 9-16 but there's no S93E events 1-8

Is this correct or I should have a S93E plugged to events 1-8?

There is also a 10 pin IDC cable unplugged under the center section.

I can't find this info in my books as they are messed up and missing a lot of pages.

[nycsudio1]

I am not getting +5v on pin 13 in the 82E20 so I think that this could be the problem.

[unitedreco]

ummm does the computer even know that you have group channels? Have you done a proper console setup in the computer where it asks how many channels etc etc....just a shot with the thought also check to make sure your ribbons are in really good under the console and the computer before you start digging into electrical and internal.