A definitive "User" guide to tape line-up....

Discussion in 'DIY Pro Audio Forum' started by st_domingo, Dec 11, 2003.

  1. st_domingo

    st_domingo Guest

    Reading a few posts on here, I'm wondering whether it's worth some of the more tape experienced guys having a whole analogue tape machine discussion at a user level.

    I was going to post a load of this on the "Tascam 32 Alignment in MA" thread, but it looks like Hasbeen is going to get a tech to do his machine. Bo looks like he's about to get into it on the "diy align / cal" on a budget.

    Sooo, is there anyone who wants this to happen, cos we could unite these two threads and get whole load of info up here.

    I volunteer to make an idiot of myself by posting first and letting the people who really know what they're doing correct me :eek: .

    But maybe it is unneccessary: in which case will someone please post something relating to Grandmothers and eggs. ;)

  2. Mark Burnley

    Mark Burnley Guest


    I second that request. I think a good way to go would be to discuss the general requirements of a line up and the theory behind it, and then with regards to specific machines and any quirks/anomalies with particular models.


    Last edited by a moderator: Mar 31, 2014
  3. Bo Hansén

    Bo Hansén

    Apr 25, 2003
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    Hi Matt and Mark,

    Sone I will do a guide to tape machine audio line-up, maybe under christmas hollydays when I have more time.

    I have work with pro-tapemachines in 30 year so it´s fun and pleasant to share some experince about this.

  4. Mark Burnley

    Mark Burnley Guest

    Thanks Bo,

    That would be amazing!


    Last edited by a moderator: Mar 31, 2014
  5. st_domingo

    st_domingo Guest

    Quick starter from a previous post; I'll try to post a bit more tommorow

    Okay, very very very basic tape line up details (and this lot is not too difficult to understand or technical, hell we even let mastering engineers line up their own machines!)

    The adjustments below are pretty standard as user controls on most professional reel to reel machines; however in some of the cheaper Tascam / Fostex machines are inaccessible to the user.

    Simple alignment adjustments for a tape machine.


    Playback head azimuth adjustment. This is a mechanical adjustment which adjusts the angle of the play head in relation to the tape path (In an ideal world this is exactly 90 degrees). This is what I think you have been adjusting for
    define[d] separation and sound


    Reproduce gain. This sets the absolute gain of the preamp that is post the playback head, and hence sets your operating level (I'll post more about this at a later date).

    Reproduce hi frequency EQ. As expected adjusts the high frequency level of the preamp post playback head about the above mentioned operating point. Do not confuse this with the NAB / IEC / AES equalization curves.

    Reproduce Lo frequency EQ. As hi freq. eq but for low frequencies. Has implications with regard to record head characteristics.


    Record Azimuth. Same as replay azimuth but for the record head.

    Record Gain. sets absolute gain of the amp preceeding the record head, and thus defines the flux level recorded onto tape.

    Record High frequency eq. Adjusts high frequency response of the amp which drives the record head about the point set by the record gain.

    Record Bias. Sets the bias level of the signal recorded onto tape. Note if you don't know much about bias, go and find out. Also note that the bias and record gain / record eq adjustments are best done as an iterative procedure.
  6. thermionic

    thermionic Guest