Tascam DM 24 Random Glitches Clock Problems

Discussion in 'TASCAM DM-24' started by deejayfrankcesco, Aug 20, 2014.

  1. deejayfrankcesco

    deejayfrankcesco New Member

    Joined:
    Aug 2014
    Messages:
    1
    Likes:
    0
    Gear:
    Tascam DM 24
    Hi guys, I read that a lot of people like me has clock problems regarded to tascam mixer, so I created this discussion to collect the various testimonies and maybe solve the problem.

    I don't know why but maybe it seems regarded to some circutry solution in several tascam product because I read about two other people with the same ramdom crackles in tascam digital cabled studio.


    The important thing is to differentiate the problems. I noticed that there are two main problems. One regarded to the firewire slot of the dm24 and the other, that is the worst, regarded to the mixer clock itself.

    The first problem is directly related to the old driver, caused because the product in discontinued. In OSX 10.9, you can see that the mixer is detected as a general audio device witouth any specific driver and if you record a track it could be noisy. I noticed the is related with the responsiveness of the graphics interface (for example if you scroll a pdf file while you listen music it glitches), so is directly related to an inefficient use of dma and other strategies to remove cpu response latency. It's normal with an old driver so the only thing you can do is use a 2408 or something similar and forget the old internal firewire card.

    The second problem is the worst because I noticed that is indipendent to daw and it is the problem that interests me the most and we have to solve. With all firewire disconnected, so withouth pc, i connected two adat fiber (mixer to motu, motu to mixer) between the dm24 and a full working 828mk2. You can make a test configuration routing an analog signal with cuemix. So I configured the system as shown.

    External audio signal -> motu -> cuemix the signal to adat -> adat to tascam -> make something on the mixer and out master on adat -> adat to motu -> cuemix signal to monitors.

    With this setup you can check your connections without pc. I test several clock configuration:

    -routing signal WITOUTH any sync : random and periodic glitches, This is normal because the clock of mixer and motu Is always a little bit different

    -routing signal sync with adat sync: random and per glitches (obviously less than before) but this is very strange!


    -routing signal sync with word clock: (75ohm termination both on or off) same problem. And this is very strange too!

    I tried 48khz and 44.1khz. The problem is more evident in 48khz.
    I tried to change clock phases, same problem.

    That is very frustrating, with my old 03D I never had this problem.
    Now I'm checking the clock of tascam with an oscilloscope so I'll tell you the conclusion later.

    :(


    Write here if you have similar problems.

    PS. an interesting technical post in this forum (http://www.tascamforums.com/threads/tascam-dm-24-power-supply-fail.136/) regard the PSU fail of the mixer that is the first thing I checked. In my case it seems working well.
  2. AcousticZ

    AcousticZ New Member

    Joined:
    Jun 2016
    Messages:
    1
    Likes:
    0
    Gear:
    DM3200/FW
    Any resolve, deejayfrankcesco ? Frustrating in deed... Thanks for your efforts
  3. wkrbee

    wkrbee Active Member

    Joined:
    Sep 2012
    Messages:
    253
    Likes:
    55
    From:
    Outside the Emerald City
    Who's the WC Master?Have you verified the WC frequency is in spec at 44.1 and 48KHZ? I had a failure like you describes some years ago, it was the 78lxx regulator for the WC PLL- Phase Lock Loop- WC circuit on the main board.
  4. alberto.irrera

    alberto.irrera New Member

    Joined:
    Dec 2016
    Messages:
    7
    Likes:
    1
    Gear:
    DM 3200 - DM24 - DAP01
    Hello! I know, old thread, but I'm deeply investigating all DM related adat/clock topics 'cause I have drops and glitches in a DM 3200 receiving digital optical signals.

    Random glitches and short drops, very noticeable in particular on adat channel 1... no fw expansion card, i'm testing on-board adat connection.

    During these christmas days, I have this tascam for test. It's an used unit I'd like to use in both studio and theatre application, where I usually work with adat-equipped interfaces for multi-track and surround, and this is an annoying problem.

    For testing I'm using an M-audio 1814, old unit but I don't think the problem is the audio interface cause I used this 1814 a lot, in similar setup (combined with Tascam DM 24 and Yamaha 01v96, and others digital desks...) until a few weeks ago, without any troubles and with the same macbook pro.

    After several test & reset of the dm3200 (sdram etc), I changed 3 adat optical cables and also opened the desk checking for pcb conditions, dust and connections: it seems very clean, no evidence of fried electronics or bad / lacky ribbon connections...

    I have a studio with a lot of gear I could use for better testing the desk, but unfortunately many km away from here: now I'm in holiday and I found this (apparently good) DM 3200 for sale along the way to visit my parents by car... here it's a rural region, no audio gear shops. I wanted to test the mixer before returning to my home, and here I have only this M-audio.

    Moreover I forgot the little m-audio snake that hosts word clock I/O for 1814, so I have only adat I/O for clocking...

    Somone could help me? Known old troubles with the on-board adat ports of DM 3200??

    Actually I'd like to use the desk with my new Motu Ultralite AVB - good piece of gear but no word clock on board, so I am not happy with this clock troubles.

    I am tempted to return the mixer to the seller during the return trip, but shit... could be a good deal (800 euros, all the rest of the desk it seems perfect!)

    Appreciate any help, sorry for the length of the post and my bad english!!

    Regards
  5. Will Miho

    Will Miho Member

    Joined:
    Oct 2012
    Messages:
    154
    Likes:
    7
    Gear:
    DM4800 DM24
    Well - I can tell you this. TDIF is the most reliable digital I/O on Tascam Boards. Any of them. If you see the old Tascam rack gear units that convert to TDIF, they are dirt cheap and work very well.