Page 1 of 4 1 2 3 ... LastLast
Results 1 to 10 of 37

Thread: Tascam 22 - Low freq. bump questions

  1. #1
    Join Date
    Jul 2004
    Posts
    1,030
    Thanks
    4
    Thanked 17 Times in 17 Posts
    Rep Power
    15498453

    Tascam 22 - Low freq. bump questions

    Sign in to disable this ad
    Hey folks. So my Tascam 22 has been functioning perfect. All is good.

    *Except*

    The low frequency bump is pretty substantial, which requires me to do a significant amount of mixing while I'm monitoring from tape. Not a deal killer, but it creates a lot of unnecessary passes on my tape, head wear, etc.

    So, are there other tapes that would not have such a bump (I'm using LPR35 @ 15ips)? Do I need to explore adjusting the bias? Is this my payback for buying a more entry-level machine?

    As always, I appreciate the help!

  2. #2
    Join Date
    Apr 2008
    Location
    Pacific Northwest, USA
    Posts
    8,553
    Thanks
    223
    Thanked 218 Times in 198 Posts
    Rep Power
    3753124
    leddy, can you better define a "substantial" head bump? You may just be experiencing the normal spec of the machine. what are you mixing through? Different tape is not going to change the head bump, but how you utilize the tape may. Have you done a calibration recently? What facilities does the 22 have for eq calibration? Can you tell us the frequency response curve of your deck? Even a rough plot...reference 0dB at 1kHz, and then the relative level at 100Hz and 10kHz even might be revealing. Add 40 or 60Hz, maybe 500Hz and 16kHz to tell a bit more...

    Sorry that may not be much help, but with a little more info it might give some direction.

  3. #3
    Join Date
    Jul 2004
    Posts
    1,030
    Thanks
    4
    Thanked 17 Times in 17 Posts
    Rep Power
    15498453
    Quote Originally Posted by sweetbeats View Post
    leddy, can you better define a "substantial" head bump? You may just be experiencing the normal spec of the machine. what are you mixing through? Different tape is not going to change the head bump, but how you utilize the tape may. Have you done a calibration recently? What facilities does the 22 have for eq calibration? Can you tell us the frequency response curve of your deck? Even a rough plot...reference 0dB at 1kHz, and then the relative level at 100Hz and 10kHz even might be revealing. Add 40 or 60Hz, maybe 500Hz and 16kHz to tell a bit more...

    Sorry that may not be much help, but with a little more info it might give some direction.
    Thanks. I'll plot that out tonight and report back.

  4. #4
    Join Date
    Jul 2004
    Posts
    1,030
    Thanks
    4
    Thanked 17 Times in 17 Posts
    Rep Power
    15498453
    Ok I just did it now.

    Here's what I got:

    1000 @ 0

    40 +3.5
    60 +3.5
    80 +2.5
    100 +2.5
    200 + 1.5
    300 + .5
    500 0

    5k 0
    10k -.5

  5. #5
    Join Date
    Apr 2008
    Location
    Pacific Northwest, USA
    Posts
    8,553
    Thanks
    223
    Thanked 218 Times in 198 Posts
    Rep Power
    3753124

    Exclamation

    Leddy...that is a healthy head bump...

    Wow...

    But that's from a tone generator to your LPR35 tape, and then looking at the levels coming off tape right?

    1. Do you have an alignment tape?
    2. Has the deck been calibrated recently?
    3. If it has been calibrated recently, or if you otherwise know the following, what level standard was it calibrated for (i.e. 185, 250, 320 nanowebers/meter etc.?
    4. Do you know what kinds of calibration trim controls you have on the 22 (i.e. I know on my 58 there are hi and low eq response trimmers)?
    5. When was the last time you demagged with a good demag unit?
    6. Is the tape path clean?
    7. What is the wear condition of your heads (i.e. flat spots, trapezoidal wear patterns on the heads)?
    8. If you playback a 10kHz tone and apply slight back-pressure to the supply reel (like with one finger on the edge, just to put a little gentle drag on it), do you see the output level of the 10kHz tone increase?
    9. Is this a new sudden problem, or has it always been that way or gradually worsened over time?


    Sorry for all the questions, but if you can answer each of them it will help me help you a bunch.

    Bullets 5~8 are really dealing with the possibility that you aren't wrangling with a low frequency head bump, but rather a high frequency rolloff due to a worn, soiled, magnetized or maladjusted tape path that is presenting as an increased low-end response but is actually causing a decreased high-end response.

    Anybody else with a 22 that can help leddy out with this?

  6. #6
    Join Date
    Apr 2008
    Location
    Pacific Northwest, USA
    Posts
    8,553
    Thanks
    223
    Thanked 218 Times in 198 Posts
    Rep Power
    3753124

    Exclamation

    Also, sorry if my questions seem basic...you have clearly been around for awhile...I always like to start from a "is there gas in the tank" approach and go from there. I have had the good fortune of respected others pointing out to me that the tank is indeed empty.

    Do you have a manual for the 22, and if so what does it say about the proper frequency reponse that should be expected?

    Also, BTW, I understand the 22 to be a fine deck. Let go of the "entry-level" hype. It is well-made with potential for great recordings.

    Lastly, you are correct that a bias adjustment may be an issue as well, right inline with my thought of the issue being not a low-end hump, but a high-end rolloff.

  7. #7
    Join Date
    Jul 2004
    Posts
    1,030
    Thanks
    4
    Thanked 17 Times in 17 Posts
    Rep Power
    15498453
    I am doing my best to live life with no ego. Feel free to ask me if I have the thing plugged in.

    Yes, I recorded the tones from Wavelab in my PC and played them back, noting the differences.

    No alignment tape.

    I have no idea if it was calibrated recently. I did take it to a local tech who said it was operating nicely. I trusted that meant it was not needed. I asked him about demagnetizing the heads and he said it was not needed. Again, I trusted him - but I know he had some prejudice against the machine. He said these were toys compared to what he normally works on.
    Nice guy, though. I'd still go back to him.

    I do not know what the calibration controls would be.

    I do keep the heads clean. They have an even wear pattern, and are in decent shape by my own judgement and that of the tech.

    Putting drag on the reel playing a 10k tone makes the output decrease.

    The deck has performed this way since I got it.

    I do have a manual, and it says +/- 3db accross the range, so I guess it's not really out of spec by much.

    Now here's some new info:
    I have another Tascam 22. I bought it from the tech who fixed this one. It was on a shelf and he only wanted $40 for it. We checked it out to make sure everything worked. I have yet to use it - I was keeping it as a spare. I will pull it out and perform the same tests and report back.


  8. #8
    Join Date
    Apr 2008
    Location
    Pacific Northwest, USA
    Posts
    8,553
    Thanks
    223
    Thanked 218 Times in 198 Posts
    Rep Power
    3753124
    I am doing my best to live life with no ego. Feel free to ask me if I have the thing plugged in.
    Right on!

    No alignment tape.
    Okay. The problem with doing your tests using tones recorded onto tape and played back is that the response curve will be influenced by the record electronics on the 22-2, as well as the D/A converter and amplifier characteristics of your soundcard, rather than just reproducing from a tape made with a known/flat response. There is a cumulative effect. Does that make sense?

    I do not know what the calibration controls would be.
    Okay. No prob. We can go there if needed, but not yet. You'd need the calibration tape first too anyway, which, if you got the short tape, would not cost too much for your deck.

    I do keep the heads clean. They have an even wear pattern, and are in decent shape by my own judgement and that of the tech.
    Any possibility that you could post up a picture of your heads? Worth a thousand words.

    Putting drag on the reel playing a 10k tone makes the output decrease.
    And you're applying the drag to the supply reel right?

    I do have a manual, and it says +/- 3db accross the range, so I guess it's not really out of spec by much.
    And what is the frequency range specified for that response range? Does your manual have the maintenance section?

    I did take it to a local tech who said it was operating nicely. I trusted that meant it was not needed.
    May have been speaking mechanically.

    I asked him about demagnetizing the heads and he said it was not needed. Again, I trusted him - but I know he had some prejudice against the machine. He said these were toys compared to what he normally works on.
    Nice guy, though. I'd still go back to him.
    May have been a nice guy, but IMHO he's doing you somewhat of a disservice if he indicates demagging is not necessary/needed. Unless he was able to measure the gauss on the heads he has no idea how magnetized they are. That could be a significant contributor. Who knows when it was done last and it can indeed have a serious effect on the high frequency response of an atr. I suggest you get a demag unit. A good one like the Han-D-Mag (it is worth it), not the $10 toys that are on eBay all over the place. I'm speaking from direct experience. Now, I think I am justified in calling those "toys", because they are not capable of getting the job done. Your 22-2 however is capable of getting plenty done and I take respectful exception to the tech referring to your 22-2 as a toy. I don't care if he spends all day working on Studer or ampex 1/2" 1/2 track decks...respect the deck and the user...no sense in him putting you in the place he feels you are. My 2p.

  9. #9
    Join Date
    Jul 2004
    Posts
    1,030
    Thanks
    4
    Thanked 17 Times in 17 Posts
    Rep Power
    15498453
    Quote Originally Posted by sweetbeats View Post
    Okay. The problem with doing your tests using tones recorded onto tape and played back is that the response curve will be influenced by the record electronics on the 22-2, as well as the D/A converter and amplifier characteristics of your soundcard, rather than just reproducing from a tape made with a known/flat response. There is a cumulative effect. Does that make sense?
    Makes perfect sense. I need a test tape or at least a different test tone generator. I will hunt down a test tape. I'm actually in the market for new converters as well, but I will still get a tape first.

    Quote Originally Posted by sweetbeats View Post
    Any possibility that you could post up a picture of your heads? Worth a thousand words.
    I'll see what I can do.

    Quote Originally Posted by sweetbeats View Post
    And you're applying the drag to the supply reel right?
    Affirmative.

    Quote Originally Posted by sweetbeats View Post
    And what is the frequency range specified for that response range? Does your manual have the maintenance section?
    40-22kHz +/- 3db @0 VU
    35-25kHz +/- 3db @-10 VU

    Yes, there is a maintenence section. I'll do some studying.

    Quote Originally Posted by sweetbeats View Post
    May have been a nice guy, but IMHO he's doing you somewhat of a disservice if he indicates demagging is not necessary/needed. Unless he was able to measure the gauss on the heads he has no idea how magnetized they are. That could be a significant contributor. Who knows when it was done last and it can indeed have a serious effect on the high frequency response of an atr. I suggest you get a demag unit. A good one like the Han-D-Mag (it is worth it), not the $10 toys that are on eBay all over the place. I'm speaking from direct experience. Now, I think I am justified in calling those "toys", because they are not capable of getting the job done. Your 22-2 however is capable of getting plenty done and I take respectful exception to the tech referring to your 22-2 as a toy. I don't care if he spends all day working on Studer or ampex 1/2" 1/2 track decks...respect the deck and the user...no sense in him putting you in the place he feels you are. My 2p.
    I will also buy a demag unit. A good one.

    Looks like I have some homework to do. I'll order the tape and demag unit. I'm going out of town for a few days, so I'll hopefully have these things next week when I'm back. I'll let you know when I'm back at it.

    Thanks again for all the great help.

  10. #10
    Join Date
    Jul 2004
    Posts
    1,030
    Thanks
    4
    Thanked 17 Times in 17 Posts
    Rep Power
    15498453
    BTW, Where's the best place to go for the ref. tape, and how do I tell what nWb/m I need?

    Sweetbeats, I PM'd you in case you don't check back here before I go.

Thread Information

Users Browsing this Thread

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

Similar Threads

  1. sorry, hereīs the right one: low freq. panel absorber questions ... john? :-)
    By fretless in forum Studio Building & Acoustic Treatment
    Replies: 1
    Last Post: 11-24-2002, 08:37
  2. low freq. panel absorber questions ... is john listening? ;-)
    By fretless in forum Studio Building & Acoustic Treatment
    Replies: 0
    Last Post: 11-23-2002, 19:40

Posting Permissions

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