Tascam 48 Calibration

Discussion in 'TASCAM DIY Repairs and Mods' started by hunrgycat, Apr 29, 2015.

  1. hunrgycat

    hunrgycat New Member

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    M-308, Tascam 48
    Hello,
    I have recently started using tascam 48 reel to reel and I love it, it sounds really good...
    except there is a fair amount of white noise. So, I am thinking(hoping) it may just need to be calibrated.

    Does anyone know how to or know a good resource/walkthrough for doing this?

    Also, a manual would be helpful, I haven't found one googling, etc.

    Thanks
  2. SkywaveTDR

    SkywaveTDR Well-Known Member

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    A manual might be available at Stereomanuals dot com or you might obtain an original one on E bay. The calibration is not hard but you will need a 250 nWb/M flux density MRL tape and a switch network and the scope and dB meter. Got all that? If not it is more cost effective to have a pro do it.
    I have one sitting behind me now that I have to go through. The white noise you hear if in source can be oscillation of incorrect op amps maybe sub'd in. Otherwise you may be listening to tape hiss which is normal at a certain level. That is why they made the DX-4D (2 of them) to work along with this machine and it quiets things down nicely.
    Last edited: Aug 12, 2015
  3. SkywaveTDR

    SkywaveTDR Well-Known Member

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    The 48 manual is a secret kept manual. If Tascam has them get it there. Stereomanuals where I buy manuals all the time does not have it.
    The white noise is probably hiss and in 8 channels it is additive. Solution is to use a dBx unit and then with a properly calibrated deck and dBx DX-4D units (2 of them) the hiss will disappear.
    How do I know this? I have been using dBx on decks for a long time. I have even done demo tapes on a A3440S and RX-9. The DX-4D are great designs and have very little trouble. The tape decks calibration needs to be tight to eliminate artifacts of the noise reduction system. Calibration unless your play EQ is turned up all the way- meaning a bone head calibration, will not make that much difference in tape hiss noise- maybe a few dB depending on record levels and the condition of the heads. Worn heads require more play EQ compensation and thus more noise.
  4. SkywaveTDR

    SkywaveTDR Well-Known Member

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    Just an update- I have been able to secure a like new service manual for the 48 and I am sending it off to Stereomanuals and in not too much time he will have copies to sell. I am getting two for my collection and his (Rick's) manuals are the best reproduced.
    You can maybe get cheaper one on E bay but I will tell you that the ones I have seen from there aren't worth toilet paper. I guess I am picky as most of my life I had worked off original manuals and problems are hard enough without trying to guess what a part is.
  5. Gravity Jim

    Gravity Jim Well-Known Member

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    I assume you have this on a virtual rubber stamp. I hate to think of you typing it ever damn time you post.
  6. SkywaveTDR

    SkywaveTDR Well-Known Member

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    Hi Jim,
    All that is there is the signature and so from the comments made I am not rubbing it in any further. So if you see it again it is not me gluing it there. I have far too little time with a lot of repairs to even answer some of the questions- I also get about 300 E mails a day but a lot is junk. I was just wanting to let those know from this time forward that a manual has been duplicated.