Stromberg Carlson ASR-333 bypass loudness?

Discussion in 'Tube Audio' started by Ziradog, Apr 16, 2018.

  1. Ziradog

    Ziradog AK Subscriber Subscriber

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    I am about done working on this amp. Schematic is here:

    http://audiokarma.org/forums/index.php?threads/stromberg-carlson-asr-333-filter-cap-values.816278/

    It uses individual gain pots, one on each channel, and a dual gang "Master Loudness" pot, which does have loudness compensation built into it. I understand how to use this set up, I have other amps with variable loudness controls, but I think I will want to just remove the loudness compensation and use this as a master gain control. It looks like the loudness compensation consists of a 4700 cap and a 47K resistor (C1 & R1 on one channel, C15 & R23 on the other). I assume I remove the cap, do I also remove or change the value of the resistor, and if so, what value should I use?

    Thanks.
     

     

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  2. peterh

    peterh AK Subscriber Subscriber

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    Lifting one end of the 4.7nF cap is all that is needed, this will make it easy to revert too.
     
    Ziradog likes this.
  3. Raul

    Raul Active Member

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    Italy
    Is this valid also for the ASR-433? I suppose yes as they are very similar (if not identical ) amps. I read a lot about removing the tone-o-matic control on Voice of Music amps (I removed it in my VoM 1448 and 1428 amps) but it's the first time I read about this feature in the S-C amps.
     
  4. peterh

    peterh AK Subscriber Subscriber

    Messages:
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    Location:
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    Deselecting loudness ( switch M15 ) is all that is needed to disconnect loudness on asr-433.
     
  5. Raul

    Raul Active Member

    Messages:
    345
    Location:
    Italy
    Oops you are right, sorry, this is the reason I never read about this mod...
     

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