Results 1 to 10 of 10

Thread: 996->456 tape bias?

  1. #1
    Join Date
    Dec 2004
    Posts
    37
    Thanks
    0
    Thanked 0 Times in 0 Posts
    Rep Power
    0

    996->456 tape bias?

    Sign in to disable this ad
    I have an otari mtr-12II 1/2" 4 track, biased for 996 mastering tape (I forget the tape maker). I want to use some new quantegy 456 tape on the machine. So my question is, what, specifically, will happen to the sound quality if I don't adjust for the bias differences? Will I lose some end of the frequency spectrum? Will is compress/distort badly? Thanks yall....

  2. #2
    Beck Guest
    Running 456 on a machine biased for 996 will result in dull recordings due to a loss in high frequency. You will also be overdriving the tape at 0 vu reference. You should have your machine readjusted for 456.

    996 was made by 3M/Scotch. Quantegy bought 3Ms tape formulations and used 996 as the basis for GP9. You can use GP9, 499 and EMTEC 900 on a machine set for 996.

    -Tim

  3. #3
    Join Date
    Dec 2004
    Posts
    37
    Thanks
    0
    Thanked 0 Times in 0 Posts
    Rep Power
    0
    Ah, thanks. Very helpful. Now, maybe someone can tell me how to figure out what bias my machine is set to. You see, there is a switch to choose between two biases, so can anyone help me guess which one is the 996 bias setting?

    patrick

  4. #4
    Join Date
    Mar 2003
    Location
    Natick, Ma (Nearer to Boston)
    Posts
    1,768
    Thanks
    0
    Thanked 0 Times in 0 Posts
    Rep Power
    0
    Quote Originally Posted by cuibono
    I have an otari mtr-12II 1/2" 4 track, biased for 996 mastering tape (I forget the tape maker). I want to use some new quantegy 456 tape on the machine. So my question is, what, specifically, will happen to the sound quality if I don't adjust for the bias differences? Will I lose some end of the frequency spectrum? Will is compress/distort badly? Thanks yall....
    You also have to set the tape tension back to 456 (if your machine was set up CORRECTLY for the 996).

    3M 996 or Quantagy GP9 will wear heads faster IF the tension is not reset for the thicker coatings. If you just re-bias, you should check your tension to make sure it is not too low.

  5. #5
    Join Date
    May 2004
    Posts
    656
    Thanks
    0
    Thanked 0 Times in 0 Posts
    Rep Power
    214487
    Quote Originally Posted by Beck
    You can use GP9, 499 and EMTEC 900 on a machine set for 996.
    That is correct as far as operating level is concerned. However, you should always re-bias for any change in tape formulation. Even if the recommended overbias level is the same for the 2 different formulations, it may take a different level of bias current to achieve that overbias reading.
    Eric

    Practice Your Mixing Skills!
    Mix Our Tracks in Your DAW!
    www.Raw-Tracks.com
    Online Mixing Forum

  6. #6
    Beck Guest
    Quote Originally Posted by Raw-Tracks
    That is correct as far as operating level is concerned. However, you should always re-bias for any change in tape formulation. Even if the recommended overbias level is the same for the 2 different formulations, it may take a different level of bias current to achieve that overbias reading.
    Well... technically yes... in practice not exactly. I had both level and bias expressly in mind. Many purists will rebias even with a different lot of the same tape, or even from tape-to-tape. The aforementioned +9 tapes all fall within an infinitesimally small bias range.

    You don't necessarily need to rebias within a class of tape until you have evaluated the performance of the new tape with the existing setup. You can, if you want to create some unnecessary work for yourself.

    The important point to remember is that 996, GP9, and 499 are bias and level compatible, and that 456, 226, 911, etc are bias and level compatible. And these two classes are absolutely not bias and level compatible with each other.

    I would be happy if people understand that they shouldn't be using 456 and 499 interchangeably, which happens all too often.

    Tape selection seems to be one of the least understood elements of recording, and ironically probably the most important.

    -Tim

  7. #7
    Join Date
    Mar 2003
    Location
    Natick, Ma (Nearer to Boston)
    Posts
    1,768
    Thanks
    0
    Thanked 0 Times in 0 Posts
    Rep Power
    0
    Quote Originally Posted by Raw-Tracks
    That is correct as far as operating level is concerned. However, you should always re-bias for any change in tape formulation. Even if the recommended overbias level is the same for the 2 different formulations, it may take a different level of bias current to achieve that overbias reading.
    I align my 2" everytime I start a session (if that session is for somebody other than me). All pro's do.

    The typical home reccer does not have to worry about it. The reason pro's have to is to guarantee that their tape is compatable with every pro studio out there. Tape decks don't go out of alignment unless they have a problem or are moved (like in a moving truck, shipped etc.).

    But, the pro's have to know for 100% sure that the deck is aligned and biased for their customers.

  8. #8
    Join Date
    May 2004
    Posts
    656
    Thanks
    0
    Thanked 0 Times in 0 Posts
    Rep Power
    214487
    Quote Originally Posted by acorec
    I align my 2" everytime I start a session (if that session is for somebody other than me). All pro's do.

    The typical home reccer does not have to worry about it. The reason pro's have to is to guarantee that their tape is compatable with every pro studio out there. Tape decks don't go out of alignment unless they have a problem or are moved (like in a moving truck, shipped etc.).

    But, the pro's have to know for 100% sure that the deck is aligned and biased for their customers.
    Yes, but if the home recorder is swapping different tape formulations around, his high frequency response will be out of whack. One formulation will be bright, while another will be dull. All due to improper bias.
    Eric

    Practice Your Mixing Skills!
    Mix Our Tracks in Your DAW!
    www.Raw-Tracks.com
    Online Mixing Forum

  9. #9
    Join Date
    Mar 2003
    Location
    Natick, Ma (Nearer to Boston)
    Posts
    1,768
    Thanks
    0
    Thanked 0 Times in 0 Posts
    Rep Power
    0
    Quote Originally Posted by Raw-Tracks
    Yes, but if the home recorder is swapping different tape formulations around, his high frequency response will be out of whack. One formulation will be bright, while another will be dull. All due to improper bias.
    I agree 100%.

  10. #10
    Beck Guest
    Quote Originally Posted by Raw-Tracks
    Yes, but if the home recorder is swapping different tape formulations around, his high frequency response will be out of whack. One formulation will be bright, while another will be dull. All due to improper bias.
    Right! Which brings us full circle back to my original reply to this thread:

    "Running 456 on a machine biased for 996 will result in dull recordings due to a loss in high frequency. You will also be overdriving the tape at 0 vu reference. You should have your machine readjusted for 456."

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. Fostex Model 80 1/4" reel2reel 8 trk QUESTIONS!!!
    By K.C. Maloney in forum Fostex Forum
    Replies: 19
    Last Post: 03-14-2007, 17:14
  2. Well boys .... it looks like it's the end of tape ... for real now ...
    By cjacek in forum Analog Recording & Mixing - Tape & Gear
    Replies: 6
    Last Post: 01-04-2005, 11:05
  3. . . .yet another patchbay question
    By tlp in forum The Rack
    Replies: 19
    Last Post: 07-08-2004, 13:56
  4. Do I need Noise Reduction?
    By Stevebol in forum Analog Recording & Mixing - Tape & Gear
    Replies: 7
    Last Post: 03-06-2004, 20:25
  5. munched-up ADAT tape
    By BigKahuna in forum Alesis Forum
    Replies: 6
    Last Post: 11-12-2001, 03:43

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •