test
test
test
test
Results 1 to 1 of 1

Thread: New recruitment: a 1/4" STUDER A820

  1. #1
    Member
    Join Date
    Jun 2011
    Location
    Taipei, Taiwan, Republic of China
    Posts
    34

    New recruitment: a 1/4" STUDER A820

    I got this STUDER also in non-functional state: none of the green LED's were lit as I got it on May 31, 2014; only a pulsing rotation of the take-up reel table at power on. After half month's struggle I located a fault of two gold fingers on master MP board, the machine started self-diagonosis with no error! It took me another day to really make it work: a MP7524 D/A convertor on spolling motor controller failed; which made the tape deck section fail to play any tape.

    I had carried out many experiments to bring the wow-and-flutter figure low. The final version of the test was to fine-tunning R41 on tacho sensor board (1.021.695.81) at the vicinity of 50% duty cycle of TD-TCH1 (IC1/pin 2); monitoring the total harmonic distortion of a recorded 1kHz signal @ 3.75ips at lowest figure from a Tektronix AA5001. The 1kHz reference signal was from a mono/stereo switch with test tone generator borrowed from my STUDER A810.

    My impression so far was: there was still room for improvement.
    Attached Images Attached Images   

Similar Threads

  1. Replies: 41
    Last Post: 08-25-2015, 12:58 AM
  2. Neat overview of Studer A820 tape deck
    By amirm in forum Reel To Reel Tape Videos
    Replies: 8
    Last Post: 08-19-2014, 08:25 AM
  3. Studer A80vu 1/2"
    By Bruce B in forum Buy and Sell Forum
    Replies: 6
    Last Post: 05-09-2013, 05:33 PM
  4. Studer A820, ATR, Ampex...!!
    By Bruce B in forum Buy and Sell Forum
    Replies: 4
    Last Post: 09-01-2012, 12:58 AM
  5. Sound quality A810 vs. A820
    By EddieSudz in forum Reel To Reel Tape Deck and Content Forum
    Replies: 5
    Last Post: 11-26-2011, 10:47 PM

Bookmarks

Posting Permissions

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