Tascam M 208 mixer problem

Edit: I have this same issue, trying to find a replacement pot atm, anyone know the name of the pot for the headphone monitor?

Found out it is this:
Ref no. R421
Parts no. 5282411000
Description: 1S2UVR 12, 20KCX2
 

Attachments

  • Screenshot 2024-04-22 at 12.25.24.png
    Screenshot 2024-04-22 at 12.25.24.png
    746.6 KB · Views: 1
Last edited:
It is R421 on the MONITOR PCB. It is a 20K A-taper pot with two elements in tandem…so it is marked “20KAX2”.

But before you go further, what is the specific problem you are having? I ask because the pot is fed by 4000 series logic (an LC4966) and there is a pattern of those going bad in a number of period Teac devices. I think this is because, and this is one of the very few issues like this in a Teac device where I’m, like, “well *that* wasn’t the best idea…”, they powered the device using the +/-15V rails, and the device has a max 30V peak-to-peak input power rating. Now, there are usually dropping resistors on the power rails of each PCB in this era of Teac stuff…like usually 33R or something, which drops the power a little bit…not a lot, but a little is better than none when you’re powering an active device at its input capacity, but I don’t even see those on the MONITOR PCB…I see them on the INPUT PCBs…22R there…but nothing on the MONITOR PCB. So that LC4966 is running right at capacity all these decades. So what’s going on with your headphone output?
 
sweetbeats said:
It is R421 on the MONITOR PCB. It is a 20K A-taper pot with two elements in tandem…so it is marked “20KAX2”.

But before you go further, what is the specific problem you are having? I ask because the pot is fed by 4000 series logic (an LC4966) and there is a pattern of those going bad in a number of period Teac devices. I think this is because, and this is one of the very few issues like this in a Teac device where I’m, like, “well *that* wasn’t the best idea…”, they powered the device using the +/-15V rails, and the device has a max 30V peak-to-peak input power rating. Now, there are usually dropping resistors on the power rails of each PCB in this era of Teac stuff…like usually 33R or something, which drops the power a little bit…not a lot, but a little is better than none when you’re powering an active device at its input capacity, but I don’t even see those on the MONITOR PCB…I see them on the INPUT PCBs…22R there…but nothing on the MONITOR PCB. So that LC4966 is running right at capacity all these decades. So what’s going on with your headphone output?
Click to expand...
I only get signal to the left headphone unless I push the monitor knob down and then I get a signal to both left and right.

I forgot about this and remember now when I used it to record when I had everything set up previously I use to tape it down to record anything that required being mic’ed up.
 
The pot is mounted to the PCB. My hunch is you just need to re-flow the solder joints. It probably got bumped at some point and cracked a solder joint.
 
Take a soldering iron and heat up each of the solder joints to melt the solder and essentially re-do the welds.
 
You must log in or register to reply here.
Back
Top