Greetings, Sending audio to the Submix (1-2) of my Mackie 1604 VLZ Pro (1999) sometimes results in no audio at the outputs of said submix. A temporary fix is to raise the gain of one (any) of the track that go into the submix - this will sort of "push open" the output (as if there is some dirt that gets blasted out and opens the flow of current). Once flowing, I can lower the volume of the submix input track again (the submix outputs stay open). But - the outputs of said submix may silence again and I have to repeat the procedure (push some high gain signal into it). Any clues why that is and if and how I can fix this? It is a bit annoying. As you might have read between the lines, I am not much of a electronic engineer... I am just hoping that this might be easy to fix, even for me... Thank you so much.
There is a dry joint somewhere and adjusting the control makes it temporarily good for a while.
As you are not an electronics engineer, I would recommend the services of a dealer to repair it.
As you are not an electronics engineer, I would recommend the services of a dealer to repair it.
Pushed the dirt aside is pretty much exactly what happened.
Without looking up that particular mixer, if there are any INSERT jacks in that sub, clean the cutout contacts inside it. Any ASSIGN push switches? Pop the cap off and dribble some Deoxit down along the push shaft to get inside and clean that. Include any MUTE buttons.
If you can determine that the issue is in the sub circuit over by the master or in individual channel assigns, that helps. Clean the assign buttons on each channel.
And lastly, Mackie older mixers are FAMOUS for ribbon cable trouble. It may take some serious disassembly, but pull every ribbon connector half way off then push it back down. That usually clears all the dirty contact surfaces.
When I get mixers like that in the shop, I usually start by going down the board, cleaning all inserts, all push switches, and all sliders. And reseating all ribbons.
Without looking up that particular mixer, if there are any INSERT jacks in that sub, clean the cutout contacts inside it. Any ASSIGN push switches? Pop the cap off and dribble some Deoxit down along the push shaft to get inside and clean that. Include any MUTE buttons.
If you can determine that the issue is in the sub circuit over by the master or in individual channel assigns, that helps. Clean the assign buttons on each channel.
And lastly, Mackie older mixers are FAMOUS for ribbon cable trouble. It may take some serious disassembly, but pull every ribbon connector half way off then push it back down. That usually clears all the dirty contact surfaces.
When I get mixers like that in the shop, I usually start by going down the board, cleaning all inserts, all push switches, and all sliders. And reseating all ribbons.
"dirt" in this case is a layer of oxide on the contacts, which makes a very primitive, poor performing Schottky diode. Hit it with enough potential (signal voltage, a couple tenths of a volt to a volt) and it burns through (avalanche breakdown - same thing that would burn up a normal diode you use in a circuit). You then get normal conduction till it oxidizes again.
Yes, it can happen ANYWHERE. Fortunately, contcat cleaner won't hurt a good contact.
Agree with above. Insert connectors are often to blame. If you can find a 22 caliber gun cleaning brush, they work wonders on 1/4"(6.35mm) connections. Just a little alcohol on the brush is all you need. Use a nylon brush, not brass.
Thanks guys. I am gonna clean all the jacks (while I am at it) with a gun cleaning brush (what kind? metal, copper, plastic?) and check the ribbon cables.
Remember, what gets dirty in the jacks is the cutout contacts, not the inside of the barrel. The brush won't touch them, but it can distribute cleaner, which is the point.
I fixed the issue but got another in the process... When the mixer was in pieces I connected everything and added some audio for testing. While reconnecting the ribbon cables over and over again to clean the contacts I sometimes managed to only connect half of them which resulted in smoke from the power supply unit and sounds like small lightnings from some unknown locations. 🙂 So - the end result is that two channels have a lower volume output than the others. It's OK (better than before) since I don't use all the 16 channels but need the submixes. Kind of lame... I guess if I would have been more careful all channels would still be OK now.
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