Tascam 388 Pan Pot - Bad?

[akpasta]

I was using the Tascam 388 at my practice space today. It belongs to my space-mate so it's not mine but I've used these before so he let me have at it. I was doing some guitar overdubbing to the left side of track 5, and suddenly the audio got all scratchy.

I figured it was a dirty head so I cleaned it, but it was still scratchy. I attempted everything I could think of to narrow down the issue. It seemes to be coming from the track itself, not the tape, not the cables, mic, or anything else.

The left side of Track 5 is almost totally dead. When I pan back to the right, the right side is perfect. I should mention, when I record or play back the VU meters on track 5 are A-OK no matter how I pan the knob.

I started comparing between other knobs on the board and sure enough, the physical pan nob on Track 5 FEELS crunchy when you turn it anywhere left of 12 o'clock. Like there's something stuck in there or something.

So I am thinking this is perhaps a dirty pot (best case) or bad pot, or worst case something even more complicated. I don't know much about these machines' internals. Any help would be great. Can I open it up somehow and have a look at the pot?

Here's a link to a video with audio of the symptom I am describing. Shows a recorded guitar on track 5, panned right (crystal clear) and panned left (fucked up). It does the same thing regardless of source (coming from recorded tape, microphone, etc).

https://youtu.be/TMT_kjKgRcA

Thank you!!

[kslight]

It’s possible. I’ve had to replace faders on a couple of the 388s I’ve had which will cause similar intermittent behavior (volume related instead of panning of course).


If you want to be sure, just open it up (bottom screws) and see what’s going on. Swap with another pot from another channel.

[akpasta]

How careful do I need to be taking it apart? Any tips? I am asusming I can't put it upside down, or can I? Is that the best way to clean the pot as well?

[kslight]

How careful do I need to be taking it apart? Any tips? I am asusming I can't put it upside down, or can I? Is that the best way to clean the pot as well?

It will completely stand upright on its back (aka the meter bridge side), just be careful not to cinch the power cord with its weight. And be careful not to let it drop, I suppose. But nothing to be overly concerned with.

There’s only a handful of screws on the bottom (depending on how many have been lost over the decades), including the screws in the rubber feet. I think you will gain access to the Pan pot from this side, but I don’t have it in front of me. You might peek at the manual first, but that’s how you get to the faders anyway. If not this way then it would be from the top.

[akpasta]

What happens if I take off the pan knob in question, and unscrew the nut holding it to the board? Can I shoot some DeOxit down there that way, or not?

[A.David.MacKinnon]

Nope. You need to get at it from the back.

[akpasta]

Thanks for the tip. I've found some pictures of the bottom with the cover off and can see you have access to the pan pots, just above the fader sliders. I should just spray some deoxit on the back of the pan pot and turn the knob?

[akpasta]

Thought ya'll might like to know I pulled the back cover off the 388, sprayed some cleaner into the offending pot and it cleared things right up! Yay!

[kslight]

Thought ya'll might like to know I pulled the back cover off the 388, sprayed some cleaner into the offending pot and it cleared things right up! Yay!

I love easy fixes!