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Question about Tascam US-122 Sound Card

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Tascam US-122, blown pre-amp?

I'm afraid I've done something stupid. I wrongly attempted to reattach a phantom-powered microphone (Behringer B-1) to the right channel of my US-122 while the phantom power switch was set to "on." Although the input volume level was turned down all the way at the time, I have apparently damaged the right channel. I can no longer obtain sufficient audio levels on that side. Even a guitar plugged directly into the right channel generates very little level. The microphone appears to be undamaged, working as previously when plugged into the left side. The Tascam is beyond warranty coverage, and before I sent it in for repair, I wondered if anyone knows if there is any internal, replaceable fusing in the US-122. If by chance there is, does anyone know how to disassemble this thing without beating it with a hammer? I truly appreciate any suggestions. Thanks.

Posted by Anonymous on

  • Anonymous Aug 03, 2007

    Thank you for your reply to my posted problem. Although I do own the manual for this item, my copy would have been difficult to locate.

    The on-line manual mentions that TASCAM maintains a user's forum, however, a search of their website seems to reveal that the official forum has been discontinued.

    Using the info provided in the manual, I was able to contact the TASCAM USA office, which put me in touch with a repair center in my state. Unfortunately, after a discussion with that center, I was told that they would not service this item, and would suggest that I send it directly to TASCAM.

    This particular service rep tells me that it does sound as though I have blown the right channel preamp, and there are no internal fuses that I can attempt to replace.

    Guess it's off to TASCAM. Thank you again for your attempt at helping.

    To all other US-122 users, be very careful to NEVER connect or disconnect a phantom powered mic while this unit's phantom power switch is on. There is apparently little to no circuitry designed to buffer the unit against a hit.

  • cupakinki Dec 11, 2007

    I have exactly the same problem with my us 122. One of the channels appears to have been blown, although I don't remember making plugging a phantom powered mic while the phantom power switch was on. I would like to know if there is some way to repair it without having to send it in for repairs



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Nitin Chandrachud

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I have the service manual & have repaired mine. Replace Q1(Left i/p) / Q4(Right i/p). The original Part is 2SK117-BL. Equivalent - BF810, 2N3822, 2SK184. If opamp is also blown - replace U7 - Part no - TLC2272CD. Actually any standard opamp will put it back in service. Care should be taken not to connect / disconnect a device when the sound card is powered up. Disconnect the usb cable first & then connect/disconnect the sound card. Hope this will help. In case of more explanation - [email protected]

Posted on Sep 13, 2013



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After a while on the net I could not find anything specific to this issue but I do have a link to the manual. which some tech specs and drawings hope this helps. copy and paste the text below into your internet browser http://www.dgmplaza.co.kr/mart_45/bbs/include/DOWNLOAD.php3?table=pds&l=111&inc=local&f=upfile

Posted on Jul 31, 2007


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