Tech discussion > 4K,6K,8K Series

Master imbalance SSL 4000E """>>>SOLVED<<<"""

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waltzingbear:
use your red and orange patch cords (converter IN) into the Main Out LF/RF jax on the patch bay. I don't see them in the photos in that position, so they must be somewhere else. You need to eliminate the external wiring in the testing by patching in there.

When you bypass the post VCA stage you have a "perfect" 6db drop. Is that still there when you patch the test cords into the points above? If so, is that a adjustment error or a problem (swap cards to investigate). It could be several problems remember, you need to keep the setup simple and short (ie use the patch points Main Out)

again, approach it in a systematic direction, measure from the outputs toward the busses, solve the problems on the way.

Alan

oyanliz:
Hi Alan, thank you so much for your help!!

Signal coming from Pre VCA is fully balanced, I am using this output for mixing, but I can not use the Buss compressor and master fader neither. I do not understund the signal flow thru the cards. Pre VCA is after 82E026? Post VCA is after 82E027? Card 82E025 is the last output card?

I have removed the 025 card, clean it a bit and put back again, but  no changes in the balance of the signal after master fader.

I will continue mixing with the Pre VCA out and I will make more test this week.

Thanks.

Oihan

paramountrec:
Try swapping the left front and right front 26 cards and see if the problem follows. If I remember correctly, the post VCA patch points are taken before the signal gets to the 25 card, so I don't think the issue is there.

Did you replace all of the electrolytic caps on the 26 cards? There's a Roderstein (sp?) capacitor that often gets overlooked - it doesn't look like a typical electrolytic.  I've seen these fail and cause the very problem you describe.

xmax:
^Yes what he said, also C7 weird ceramic cap can cause this. And neither the pre or post vca
sends are balanced so I do not see how it could be missing a leg. If it's fine on the pre vca and
6dB down on the post the problem is on the 26 card or something is causing the compressor
to compress 6 dB all the time (check control voltage to vca).

oyanliz:
Hi all,

Thank you so much for all the comments.

I´m so sorry because I did not have time for posting before.

I made more testings and I have taken some pictures of my 026 cards. Before I post my problem here, in the forum, a technitian tried to fix the problem and he made a modification in the cards. He told to me that he left the console calibrated, but still it is not balanced and I still do not know what is the problem. For the moment we are mixing with PRE VCA outputs, so the console it is working at least.

The technitian cut a resistor on both 026 cards and soldered a trimmer in the back side of the cards (see pictures), I was not convinced with it but he says he left the LF-RF outputs calibrated so I should touch the trimmer if the outputs are imbalanced again.

I would be very grateful if someone could give me some ideas for fixing the problems (I see the problem is on the 026 cards) by myself.

Thanks to all, once more.

My very best regards.

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