Tascam 688 -Channel 1 plays thru mix even when the fader is down-HELP!

juanpablo

New member
Hi,

Thanks everyone for participating on this forums. I have learned a lot over time but this is my first post. I hope to find help...

So, I have had a Tascam 388 for years and lately it started to have problems.

I am trying to mix a track down thu GROUP 1-2 as I usually do but for some reason a lot sound from track 1 leaks into the mix. I have the CUE MONITOR, ALL AUXs and DUALs down, plus all the faders for the individual tracks. As soon as I raise the volume for the MASTER fader 1/L-2/R track 1 can be heard even when the fader is all the way down!!!

It's driving me nuts. I have been looking all over the board for the last couple of days to see if I can find where the sound is coming from and I have no clue. It is impossible to mix this way.

Has anybody dealt with something like this before?

Please let me know if you can help.

Thanks,

Juan P
 
I do not work on these anymore but the Fader take a signal in hot at one end and then the slide is the output and if the ground end of the fader is unsoldered, broken or dirt isolating the wiper it will not ground out the signal allowing it to remain. Clean fader with Fader Lub and then chck if the brown substrate section of the fader has a crack in it. If it doe s then a new part will be required. This comes from dropping item on the faders- they are not made to take a lot of abuse.
 
Hi,

I know it's an old topic. But i'm having the exact same issue on my 644, i'm very curious if OP was able to solve this and how.
 
You know if you examine the Fader circuit it has a hot terminal a ground terminal and then a contact that runs up and down the carbon strip between the two. What happens is that some people put heavy item on the equipment and it crack the carbon layer thus removing the ground from the carbon. Or that dirt gets in the fader and keep the slide contact from touching the carbon that is suppose to ground out the signal. I would be looking at the fader integrity when something like this happens. It might even be pushed out the back- I have seen fader phenolic layer pushed out the metal supports.
 
There are some decks like the 688 that have electronics switchers in them that feed the signal directly not through the fader of that channel. These can be hard to understand for most people as even an Engineer and person who has worked with these for years can make mistakes. I worked with Sierra Routing switchers in Broadcast of AM and FM stations as Chief Engineer in Radio stations so I have more of an idea about routing switchers and actually they are easier to work on than the 688. Some routing switchers cost $68,000.
They take some getting used to. I am not sure the 644 had these yet.
 
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