Monday, September 9, 2019

Sound Technologies ST1500A - Tape and LP Test System

Chris and have been working on this guy off and on for a while. There is finally light at the end of the tunnel.  Here is a pic of the ancient guts.

 With these boards removed we get all the correct voltages. Not so much when they are installed. I started replacing all the orange tantalum caps... Lots of caps.
This is what the input board does to the 1500A. Very sad. 

 Fortunately with the input board removed there are some signs of life.

 Can't belive how happy I was to see this boot up screen.. LOL.... Now back to replacing all the tantalum caps on that dam input board and hope it works.


9 comments:

  1. Very cool, hope you can get it back up and running!

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    1. Actually just got the input board working. Replaced a crap ton of tantalum capacitors. Just need to go through calibration and tests 8-)

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  2. Hello Gentlemen!
    Who would have a service manual for this machine for sale ?? I'd love to pay for a good copy too! I'm thinking of replacing a TV picture tube with a 5 "LCD video monitor ... But so far, the tests have failed because the screen is getting a bad signal. i still need the service manual.
    Thank you in advance for all your help and understanding.

    Your Sincerely Attila Dragon from www.dragonaudio.hu

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    1. There was an ebay seller that sold copies of the manual. This was a very dificult piece to get working.

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  3. Hi Dear Iain !
    Thanks for the info, but it won't give me a copy yet. Can't help me contact the manufacturer? Is this company still alive ??

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  4. Hi Dear Friend! Today I climbed to the waist and replaced quite a lot of tantalum. But there was still something to do. The point is that the machine has started! But unfortunately in the oscillator module there is a tiny bulb that has broken both pins, and I have no idea !? If anyone has any info on this please share with me !! And if I manage to properly fix the instrument then I will break down the champagne and I will not be a tight-lipped sender for you ... Yeah I forgot to say that with a fully closed input one channel drops to -63 dB and the other to -76 dB! So the input stage is probably damaged and so I will replace all ICs. First step to NE5534! Including 21 pcs. is in the device. Have a nice day everyone ...

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    1. Hey send me pictures of the part in question. I'll see if I can help this weekend. iain42@gmail.com

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  5. Dear Friend Iain ...
    Thank you for your help, I apologize for not responding but I was sick. I go to work on Monday and then take a picture of the ominous unit. In the meantime, I wish you a pleasant weekend.

    Your Sincerely Attila

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