Certain tracks recording lower (Tascam Portasudio 414)

[Joelstitch]

A friend gave me a Tascam Portastudio 414 but I am having issues with 3 of the tracks. I tried multiple High Bias tapes. The problem I have is that Line 1 and 2 sound lower than what is recorded and Line 4 doesnt work at all, track 3 is the only one that records fine. I cleaned the heads and nothing different. I recorded the same song at with the same setup on all 4 tracks and thats how I know the difference. Is there a way to fix this?

 

[A Reel Person]

...

Check that the dbx switch is set to ON and not SYNC. The Sync position will disable track 4. Then make sure again that the head is spotlessly clean. After that, there's not much in the way of user tasks or controls to affect this, but often older machines will need to be recalibrated internally to get all the signal path up to snuff. Verify the record/playback function as much as possible and on as many different decks (and with as many different tapes) as possible before reaching any firm conclusions. There is a splitting point where you need to verify if it's not reading playback up to levels, not recording up to proper levels, or both. In my experience with other vintage decks it's a combination of both. If the recording/playback response is not up to par, short of calibration you may opt to record hotter on those lower tracks. This will help compensate up to the point where you're overloading the channel or record electronics, which would be undesirable.

 

[Joelstitch]

Check that the dbx switch is set to ON and not SYNC. The Sync position will disable track 4. Then make sure again that the head is spotlessly clean. After that, there's not much in the way of user tasks or controls to affect this, but often older machines will need to be recalibrated internally to get all the signal path up to snuff. Verify the record/playback function as much as possible and on as many different decks (and with as many different tapes) as possible before reaching any firm conclusions. There is a splitting point where you need to verify if it's not reading playback up to levels, not recording up to proper levels, or both. In my experience with other vintage decks it's a combination of both. If the recording/playback response is not up to par, short of calibration you may opt to record hotter on those lower tracks. This will help compensate up to the point where you're overloading the channel or record electronics, which would be undesirable.

The DBX was on off and I played with it while recording but nothing changed on any of the tracks. I can probably get away with recording on track 1 and 2 very high but nothing can be done about track 4.

 

[Joelstitch]

I tried recording at a higher lever on tracks 1 and 2 but it sounds too bad to want to keep and track 4 I can't figure out anything to get it to work. How do I recallibrate the Tascam? any other tips that could lead me to the right direction for fixing this?

 

[A Reel Person]

My friend,...

there is quite a bit to internal calibrations that would require a fair amount of expertise, specialized tools, etc., that I could explain in detail but would probably not do you any good. The tools themselves would require substantial investment. Since your friend gave you the 414, maybe he could help you test it out to your satisfaction, so that it eliminates the very sight chance that there's something in your procedures that is causing this problem. Beyond that, it could probably be fixed by posting it to TEAC in Montebello, CA, and for perhaps $100-$125 or so repair cost plus shipping get it back to working order. However, when a 414mkII often goes on eBay for $80 or thereabouts, repair may not be practical on something someone gave you. A free Portastudio that works is great. Less good if it doesn't work.

Probably the biggest hinderance to home calibration is that you'd need a standard alignment tape which is obsolete, hard to find, and if you could find it would cost over $100 alone. You would also need some sort of tone generator and a volt meter to verify input/output levels. Of course you'd need the service manual, which Tascam may sell for about $30.

I'm not trying deliberately to be discouraging, but I have these tools and have calibrated a few machines, and it could take an experienced tech such as myself many hours, if you want to be very exacting about getting things dialed right in, like I do. More experienced guys around here will know when I reiterate the notion that a 2-head deck is way more difficult, tedious and time consuming to calibrate than a 3-head deck. All Portastudios and most consumer cassette decks are 2-head recorders.

With that being said, I'll be one of a few people here that will vouch that the 414 is a very nice recorder setup that sounds excellent when it's working. Personally, I have a couple of them myself that need fixing, but that's probably another story.

I'm not trying to boost myself up or burst anyone's bubble, but as far as Portastudio calibration goes, it's a deep subject and there's a lot to it.

Back to your issue, specifically, if you feel comfortable enough to burst this unit apart with a screwdriver, the least you could do is pull and reseat all connectors, just to verify it's not a dirty or tarnished internal connection. A mid level technical novice could probably do that. Calibration is another thing entirely, to do it right. A more experienced techy type could probably take a screwdriver and the service manual, and in a matter of a few internal tweaks get levels back up to usability, but without a standard alignment tape to start, it maybe functional but it wouldn't be aligned to any standard.

That is a long answer to a seemingly simple question, but under the surface that question is not simple at all.

 

[zmb]

Have you checked the fader itself? I was having some trouble with my channel 1 (wouldn't record anything at all, made ugly noises when moved). I cleaned the fader by spraying some contact cleaner from radioshack right in the slot there from the front panel (it's hard to access the faders from inside, I've found), jiggling it up and down, waiting a few minutes for it to dry, and it works fine now. I guess the signal goes through the fader itself so if the contacts are dirty that might be the issue.

Does the volume still go up or down proportionally with the position of the fader? If so then maybe what I described is not the issue, since a dirty potentiometer would probably be unpredictable and scratchy.