424 MkIII problems

bungler666

New member
Hello, I just bought a Tascam 424 MkIII off ebay, in almost unused condition.
Everything works great but there is one problem.

There is a clicking sound coming from the master fader periodically.

It's an irregular clicking, and the volume level of it is the same regardless of the volume of the individual tracks.
When turning down the master fader, the clicking gets lower in volume.
It does not matter whether I have dbx on or off.

The strange thing about this is that the problem almost always appears after I have recorded with it for a few hours. It never appears if I just record a few short recordings.

The heads have been cleaned and demagnetized and the problem is still there.

Any help with this?
 
What is the rate of the clicking sound? That description does not give too much to go on and it could also be mechanically related too.
 

joblowme

New member
i would definitely start by taking it apart and cleaning everything. its not as intimidating as youd think. i actually had one of those for a short period. to be honest lol i actually cut the erase head out of it to put it into another unit that i had. when i first got the other unit it was stuck in the on position and i was brand new to 4 tracks and was trying to manually disengage the reader and pulled on the erase head like an idiot and unknowingly partially peeled it from the erase head. and like an idiot i spent weeks trying to firgure out why i couldnt get to erase. thought it was fucking strange though that there was no erase button on the damn thing and when i tried to retrack over recordings it would only part6ially erase it and i was so confused. ive learned alot about them thought since then. they are lots of fun. at one point people just kept bring me old cassette players and id fix them if possible. it was so bizzare thought hiow for a short time in my life cassette players and four tracks were practically being thrown at me from every direction.
 
It is never a good idea to take an erase head out of a unit that you expect to work normally. The erase head present a load to the oscillator and when that is removed the bias will be all over the place- probably too high and the unit will be useless for recording from that point on or erasing for that matter with that head out. "I took out an erase head" Usually means you are parting out a machine not to be used from then on.
 

joblowme

New member
It is never a good idea to take an erase head out of a unit that you expect to work normally. The erase head present a load to the oscillator and when that is removed the bias will be all over the place- probably too high and the unit will be useless for recording from that point on or erasing for that matter with that head out. "I took out an erase head" Usually means you are parting out a machine not to be used from then on.
lol what i meant was that i tookt the erase head out of a similar unit and put it into mine. i didnt just completely remove it and leave it like that. and the erase head that i replaced it with looked exactly like the broken one. they might be different some i guess but it erases and records
 

joblowme

New member
lol what i meant was that i tookt the erase head out of a similar unit and put it into mine. i didnt just completely remove it and leave it like that. and the erase head that i replaced it with looked exactly like the broken one. they might be different some i guess but it erases and records
but is does have weird playback issues. the recordings them self sound fine though. it just get super fucking loud when i play it back. blows your fucking ear drums out
 
Most likely the play gain or record setting is all goofed up. A broken solder joint in a op amp feedback circuit can cause the gain to go up to 20,000 when it might have been designed for 100. Portable devices are made for profit and all of the Japanese wave solder manufactuing is sub grade solder joint wise. Add to this these are portable which means they get dropped and bounced around- most the solder joints in the unit will not take that for long. If you study the gain structure of an op amp circuit the Rf as in feedback resistor kind of programs the gain on the op amp circuit along with the Ri input resistor. If a join cracks and allows a 2K resistor to go to infinity then watch out on the gain. Just saying this is one possibility as transistor circuit will not do this they just stop working or gain goes down.
 

joblowme

New member
Most likely the play gain or record setting is all goofed up. A broken solder joint in a op amp feedback circuit can cause the gain to go up to 20,000 when it might have been designed for 100. Portable devices are made for profit and all of the Japanese wave solder manufactuing is sub grade solder joint wise. Add to this these are portable which means they get dropped and bounced around- most the solder joints in the unit will not take that for long. If you study the gain structure of an op amp circuit the Rf as in feedback resistor kind of programs the gain on the op amp circuit along with the Ri input resistor. If a join cracks and allows a 2K resistor to go to infinity then watch out on the gain. Just saying this is one possibility as transistor circuit will not do this they just stop working or gain goes down.
If the gain was boosted to that extreme wouldn't everything be fairly distorted. Casue the recordings them self actually sound pretty damn good for a cassette its just very very loud on playback
 
So what did you find? Usually the play function is checked and if that is good then the mixer levels and then record levels. If the input levels seem correct then it could be record levels. Maybe someone adjusted the deck for some of the NAC chrome tape that had a 5-6 dB lower output. I had one deck I adjusted to XL II here and then when he said I use that NAC 799 when I tried to calibrate the deck to that the record levels would not even go up to 0 Vu. I advised him to get rid of the 799 and use the Maxell XL II as it was designed for or the SA or SAX. The best Chrome tape made came from TDK and was HDX which was a low metal variant.
 
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