DCC 730, as if I hadn’t recorded at all…

Apologies if this topic has been covered before, I’ve only just discovered DCC & I have a DCC730 model. The fault is, when recording (I’ve only tried the coax socket so far) the sound is there in monitor mode & whilst recording but when playing back, the original recording is still in tact & no new recording, as if I hadn’t recorded at all. I did read something that said the erase head could be faulty or not connected correctly but I don’t see where the erase head is. If it’s in the main head block, it looks as if there is only one ribbon connector to that & it looks too delicate to disturb. Any help would be greatly appreciated. Rob.

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Please check the heads in Service mode for all zero’s.

  • Put in a pre-recorded tape.
  • Power Off.
  • Press Stop and Start button simultaniously and Power on.
  • Press Play
  • Pres Next button while playing. Press Next again to see the individual heads.

Let us know what you see.

  • Power Off and On to return to normal mode.

Good luck,

Thanks Henrie,
All the heads show 00 apart from 9 which shows 10
Regards, Rob.

That’s correct. The heads are fine. Head 9 is always 10. Among other things, head 9 writes track info.

I don’t know if there are seperate erase heads present in the head structure.
My bet would be on the electronics that provide the erase current.

Maybe you have 2 DCC players? You can check if the erase current differs from each player.

I have another one but it’s just for spares. It plays analog tapes but can’t play DCCs. I don’t think that one would be working as a reference. When I read that it could be an erase head issue, I didn’t think that was likely anyway, I’d’ve thought it would’ve still recorded but not erased the previous recording, though I don’t know what that would sound like on digital recordings??
All the best, Rob.

Welcome to the forums!

DCC doesn’t use an erase head. With analog tape, the erase head basically demagnetizes the tape to record silence, and the recording head magnetizes the tape with music again, where the magnetization follows the analog signal.

But with DCC, the bits on the tape are stored as tape that’s fully magnetized in one direction or the other. Demagnetized tape has no meaning for DCC. So to record a new digital stream of bits, the DCC record/playback head only has to magnetize the tape, and the magnetization generated during recording has to be enough to re-magnetize a bit from the previous recording into the opposite direction.

Normally, of course, the circuitry and the heads take care of this just fine. But if the previous recording doesn’t go away, there’s something wrong with your recorder (you figured that out already didn’t you). It’s possible that there is no write current or that the write amplifier is not getting enabled or that the connection from the write head to the amplifier board is disconnected or something. I don’t think I’ve ever heard of anyone having this problem before except when trying to overwrite a prerecorded cassette. For some reason some prerecorded cassettes seem to be magnetized with much more force and they are much more difficult to overwrite.

So if you can, try to make some recordings on other tapes. If you have a “virgin” tape and you still can’t record anything, there’s definitely something wrong with your recorder. If you can overwrite some tapes but not others, there’s a possibility that adjusting the write current may fix the problem.

Either way, we recommend that you don’t try to fix your DCC recorder unless you know exactly what you’re doing. Contact Dr DCC for help; your recorder is almost certainly repairable in the state that it’s in now.


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Hi Jac,
Many thanks for that info.
Best regards, Rob.