New Tascam 388 headphones crackling

MagnumPI

New member
Hi All,
My Tascam 388 that I just bought a week ago is working well. All tracks sound great, etc.
The only problem is the headphones are crackling and popping. The sound doesn't effect the recorded tracks but is very annoying. Both headphone jacks have the same problem. I tried different headphones but the sound remains. Sometimes it gets REALLY loud for a few seconds.
Any ideas what this might be an how to cure it?
Thanks Guys!:listeningmusic:
 
This happened to the 2nd 388 I bought.
It turned out to be the capstan motor. It was bad.
I had a spare and replaced it and the noise went away.
This might not be your problem, so I'm not sure.
Do you hear this noise when you wear phones and
Set the capstan spinning by lifting the right tension arm without tape?
 
Thanks j.harv,
It happens even when nothing is playing or spinning.
I'm thinking its the headphone inputs. Maybe dirty? but why both?
Do you think it could still be the capstan motor if its crackling even when nothing is happening?
 
Probably not the motor then. My headphones would snap,crackle,pop when the capstan started spinning.And the motor was making an audible noise too. A lot louder than the quiet whirring noise it usually makes. I pulled it and spun it by hand and it almost felt like there was sand in it. This noise was getting fed into the rest of the circuitry.
 
Do you think I should spray some contact spray into the headphone input jack, or would I have to open this thing up in an effort to reduce the crackle?
 
I suspect there is a failing component on the headphone amp PCB, which is located underneath the transport control panel. I don't think contact cleaner will help bit it won't hurt either.
 
ah. too bad. I was thinking about taking it to Tascam in Montebello to see how much they might charge. Any guess?
 
No clue, and you'd want to call first to see if they can do it. I don't know who they have there in analog support now...I just know that the two analog gurus that were there forever are long gone unfortunately.

Can anybody comment on what type of component failure might typically cause that sort of intermittent crackling in an opamp-based audio amplifier circuit? I'm thinking electrolytic coupling cap or transistor (which would include theoretical transistors within the opamp)...

Magnum does the crackling change depending on how hot the signal is to the headphones? Like if you crank it does it make the crackling worse or does make it better? Or is it just totally random?
 
So I got some time to make a good test today and this is what I've found:
1. When I first turn on the Tascam 388 there is a LOT or crackling and popping.
2. after a few minutes it subsides on its own.
3. I can only hear it when the master fader is up.
4. As stated before the wheels dont need to be spinning for the crackling to happen.
5. When I use the EFF Master dial the cracking and popping is LOUD. If it stops, I can get it started again simply by turning this knob a bit and voila....back to big crackle and poping.
6. Same for the MON button (starts the crackle)
7. There can be long periods of time without this problem. Then slowly like a pot of water boiling it starts, and subsides a few minutes later as if you turned off the heat and the water slowly stopped boiling.
8. Popping does not show in the VU meter or print to tape (even at loud volume)
9. It really "sounds" like a dirty pot on a guitar amp before you giggle the knob a bit to "get the dust out".
Hope this info helps,
What do you think?

p.s. Magnum does the crackling change depending on how hot the signal is to the headphones? Like if you crank it does it make the crackling worse or does make it better? Or is it just totally random?
Its the same crackle, just louder when the volume is up.:)
 
I also noticed that the effects coming through the FX channel is WAY less effected and quieter than simply running it directly through an individual track channel. Is that because on the individual channel it is at 100% and through the FX Master it would be turned to max to get that 100%, so anything below max is going to be quieter and less effected?
 
I'll take your clues and see if I can narrow down a potential culprit or culprits on the schematics.
 
So I got some time to make a good test today and this is what I've found:
1. When I first turn on the Tascam 388 there is a LOT or crackling and popping.
2. after a few minutes it subsides on its own.
3. I can only hear it when the master fader is up.
4. As stated before the wheels dont need to be spinning for the crackling to happen.
5. When I use the EFF Master dial the cracking and popping is LOUD. If it stops, I can get it started again simply by turning this knob a bit and voila....back to big crackle and poping.
6. Same for the MON button (starts the crackle)
7. There can be long periods of time without this problem. Then slowly like a pot of water boiling it starts, and subsides a few minutes later as if you turned off the heat and the water slowly stopped boiling.
8. Popping does not show in the VU meter or print to tape (even at loud volume)
9. It really "sounds" like a dirty pot on a guitar amp before you giggle the knob a bit to "get the dust out".
Hope this info helps,
What do you think?


Its the same crackle, just louder when the volume is up.:)

  • Where/how are you monitoring when you hear the crackling/popping? STEREO OUT jacks or MONITOR OUT jacks/headphones?
  • "Same for the MON button (starts the crackle)" What is the "MON" button? Do you mean the MONO button?
  • Is the crackling/popping present at the AUX or EFF OUT jacks?
 
Where/how are you monitoring when you hear the crackling/popping? STEREO OUT jacks or MONITOR OUT jacks/headphones?
"Same for the MON button (starts the crackle)" What is the "MON" button? Do you mean the MONO button?
Is the crackling/popping present at the AUX or EFF OUT jacks?

Thanks sweetbeats!
*The crackle is coming from both headphone jacks. I don't have monitors yet so haven't checked that.
*Yes, MON button is MONO (sorry)
*How would I test to see if the noise is coming out of the AUX or EFF OUT jacks? (print something to tape with FX on it (from EFF OUT) and see if the crackle is there?)
Thanks again. I appreciate the help!
 
Do you have a home receiver or something you can hook the MONITOR OUT jacks to using RCA to RCA cables to see if the crackling/popping comes from them too? I have a pretty sure hunch it is yes, but I want to be sure.

As far as the AUX and EFF out jacks same thing...RCA to RCA cable with a 1/4" TS to RCA adapter, or if you have one simply a 1/4" TS to RCA cable connected to a home stereo.
 
I dont have a home receiver but maybe I can go out of these spots into my protools 002 and see if the crackle is there?
Do you think that might work?

Or could I go out to a guitar amp?
 
Thanks sweetbeats.
Well, my friend came by with his truck today so I took the 388 down to TEAC. I thought I might as well get whatever it is fixed, and checked/cleaned. Ill let you know what they determine is the "crackle" problem. I should have word from them in the next few days. I do wonder what it is....
 
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