Results 1 to 10 of 10

Thread: Using a playback cal tape with a different tone than the reference tone...thoughts?

  1. #1
    Join Date
    Apr 2008
    Location
    Pacific Northwest, USA
    Posts
    8,553
    Thanks
    223
    Thanked 218 Times in 198 Posts
    Rep Power
    3753124

    Using a playback cal tape with a different tone than the reference tone...thoughts?

    Sign in to disable this ad
    So I have a machine that calls for a -5dB 315Hz reference tone for calibrating playback level. We are talking about Akai MG series, so proprietary tape stock and cassette format etc...cal tapes are OOOOOBER rare, okay?

    Thanks to j.harv for spotting a set of Akai cal tapes on eBay for the MG series machines. The trick is the full set of cal tapes for those machines is a set of 5 tapes. The set I bought has 3 of the 5 tapes. One of the missing tapes isn't that big a deal...the wow & flutter test tape for the slow transport speed. The other tape that's missing is...

    [drum roll]

    ...the 315Hz playback level tape. The closest tape in the bunch is a -5dB 1KHz tape. So I could certainly use that to calibrate the playback level, but I think it's safe to presume the machine's response curve is such that the reference tone reproduced at 315Hz is either louder or quieter than 1KHz.

    In order to use the 1KHz tape and get as close to the level set by the 315Hz tape that is missing, I was thinking of (when I actually get around to getting one of my two MG1212 units working) recording 315Hz at -5dB across all tracks, and then doing the same with 1KHz, and then comparing the playback levels between the two tones on each track, and then finding the average difference...I'd then use the result as a ballpark amount to offset (either louder or quieter as appropriate) the reference playback level from the 1KHz tape.

    I'm thinking that would get me close enough. What do you all think? Am I out of my gourd?

  2. #2
    Join Date
    Jun 2010
    Location
    Douglas, Az.
    Posts
    1,864
    Thanks
    76
    Thanked 149 Times in 147 Posts
    Rep Power
    53222
    Naw, your fine.

  3. #3
    Join Date
    Apr 2008
    Location
    Pacific Northwest, USA
    Posts
    8,553
    Thanks
    223
    Thanked 218 Times in 198 Posts
    Rep Power
    3753124
    Meaning my idea is sound?

  4. #4
    Join Date
    Apr 2008
    Location
    Pacific Northwest, USA
    Posts
    8,553
    Thanks
    223
    Thanked 218 Times in 198 Posts
    Rep Power
    3753124
    Ooooo...except the playback-only difference between the levels of the two tones would only be roughly half that of the sum difference of the record and playback difference...so I need to find the average and divide by 2. That's the bit that was gnawing at my brain.

  5. #5
    Join Date
    Jun 2010
    Location
    Douglas, Az.
    Posts
    1,864
    Thanks
    76
    Thanked 149 Times in 147 Posts
    Rep Power
    53222
    Well, levels will be different on different formulations. Keep notes and guesstimate how much 1k level has been lost over time

  6. #6
    Join Date
    Jan 2014
    Posts
    52
    Thanks
    0
    Thanked 2 Times in 2 Posts
    Rep Power
    27756
    Quote Originally Posted by sweetbeats View Post
    Ooooo...except the playback-only difference between the levels of the two tones would only be roughly half that of the sum difference of the record and playback difference...so I need to find the average and divide by 2. That's the bit that was gnawing at my brain.
    Your machine should have flat response at 315 and 1 kHz, so the level should be the same. The important thing is you also need tones at the high and low frequencies. 10K and 100 would be good.

  7. #7
    Join Date
    Apr 2008
    Location
    Pacific Northwest, USA
    Posts
    8,553
    Thanks
    223
    Thanked 218 Times in 198 Posts
    Rep Power
    3753124
    Quote Originally Posted by garww View Post
    Well, levels will be different on different formulations. Keep notes and guesstimate how much 1k level has been lost over time
    There was only one formulation of tape, rumored to be similar to EE type tape, and the MK20 tapes used for the cal tapes are the same formulation and similar era to the NOS MK20J tape I'll use for my record reproductive level comparison.

  8. #8
    Join Date
    Apr 2008
    Location
    Pacific Northwest, USA
    Posts
    8,553
    Thanks
    223
    Thanked 218 Times in 198 Posts
    Rep Power
    3753124
    Quote Originally Posted by radardoug View Post
    Your machine should have flat response at 315 and 1 kHz, so the level should be the same. The important thing is you also need tones at the high and low frequencies. 10K and 100 would be good.
    There's no guarantee the MG1212 will be flat at 315Hz and at 1KHz. Otherwise why wouldn't they just use 1KHz as the reference tone? I can tell you my Tascam 388 was t the same at 400Hz and 1KHz...400Hz is the playback level response tone reference for that machine...

    The only cal tape tones for the MG series are 315Hz, 1KHz, 3,150Hz, and 20KHz. 100Hz, 1KHz and 10KHz would be typical and ideal, but you can't go to MRL and get a cal tape for these machines. Only possibility is to buy a 1/2" tape and try to load it in the Akai cassette, but the tape thickness and reference standard are a mystery. I'd guess 1mil tape stock and 250nWb/m but I don't really know. So if Akai says the machine can be calibrated with the 4 tapes and those 4 tones that's good enough for me, it's just a bit of a hitch I don't have the 315Hz tape.

  9. #9
    Join Date
    Mar 2008
    Location
    Montreal, Canada
    Posts
    265
    Thanks
    4
    Thanked 6 Times in 5 Posts
    Rep Power
    187210
    Hey Cory, maybe a flux loop could augment your test tape?
    If you haven't already seen it, Dale Manquen wrote a great tutorial.
    A magnetic viewer like this might be useful if you need to adjust the head height/tangent.

  10. The Following User Says Thank You to ethyrvalve For This Useful Post:


  11. #10
    Join Date
    Apr 2008
    Location
    Pacific Northwest, USA
    Posts
    8,553
    Thanks
    223
    Thanked 218 Times in 198 Posts
    Rep Power
    3753124
    Those are both good ideas, Pete. Thanks for them and for the links.

Thread Information

Users Browsing this Thread

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

Similar Threads

  1. Replies: 2
    Last Post: 06-25-2016, 00:06
  2. Replies: 7
    Last Post: 06-18-2013, 14:03
  3. help matching my tone with reference tone..
    By skiz in forum Guitars and Basses
    Replies: 20
    Last Post: 08-11-2008, 11:38
  4. Ovation Collectors Guitar - Tone tone tone
    By SgtRail in forum Free Ads for Music/Recording Equipment
    Replies: 27
    Last Post: 04-04-2005, 20:50
  5. Creating test tone / reference CD??
    By formerlyfzfile in forum Recording Techniques
    Replies: 4
    Last Post: 03-08-2004, 19:56

Posting Permissions

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