Posted by Shropshire Lad (A) on March 20, 2009 at 21:29:32

Hi All,

Seeking some assistance in sorting out my Billies.

I have a problem in that the amps dont go very loud (95 db speakers , small room). When I turn the volume up the sound simply stops and the 300b glow blue. Cured by switching off the amp, turning the volume down and all is OK again. One suggestion is that the problem may be the fillament voltage is only 3.9 v not the 5 V as expected.

Would this account for the symptoms and any suggested solution / advice is greatfully recieved.

Thanks

• RE: Bille Trouble - bcherry 05:38:36 03/24/09 (2)
  In Reply to: RE: Bille Trouble posted by Shropshire Lad on March 20, 2009 at 21:29:32

  can you provide some of the other voltages:
  300b and driver tube anode voltage
  voltage across 300b cathode resistor
  filament voltage at rectifier and driver?
  thanks
  Brian
  DIY - Done Right!
  
  

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  • RE: Bille Trouble - Shropshire Lad 10:40:27 03/25/09 (1)
    In Reply to: RE: Bille Trouble posted by bcherry on March 24, 2009 at 05:38:36

    Brian,

    Just done the measurements as per instruction manual as you requested

    Amp 1
    
    Across Driver Tube B7 - B8 - 6.7(5.8)
    Across Rectifier A2-A8 - 5.0(4.2)
    300b C1-C4 - 5.0(3.6)

    Gnd -C2 - 383
    Gnd B6 - 1.2
    Gnd B2 - 320
    Cathode Resistor - 45v

    
    Amp 2

    Across Driver Tube B7 - B8 - 6.6(5.8)
    Across Rectifier A2-A8 - 5.1(4.1)
    300b C1-C4 - 4.8(3.8)

    Gnd -C2 - 412
    Gnd B6 - 1.3
    Gnd B2 - 345
    Cathode Resistor - 29v

    The numbers in brackets are the same maesurement WITH with GZ34 tube in place, first voltages with rectifier removed. Note the vlotage drops with the rectifier in situ and the low voltage across the cathode resistor.

    Any clues ?

    Thanks
    
    
    

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    Edits: 03/25/09

    • RE: Bille Trouble - bcherry 23:23:00 03/26/09 (0)
      In Reply to: RE: Bille Trouble posted by Shropshire Lad on March 25, 2009 at 10:40:27

      So just installing rectifier loads the voltages down like that?
      And both amps the same effect.
      Can you email me with some history on these amps and primary voltage configuration etc.
      regards
      Brian
      DIY - Done Right!
      
      

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• RE: Bille Trouble - xaudiomanx 19:34:32 03/23/09 (0)
  In Reply to: RE: Bille Trouble posted by Shropshire Lad on March 20, 2009 at 21:29:32

  I would post this question on the DIY/Tubes forum. Those guys are real good.
  
  

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• RE: Bille Trouble - GTCharlie 23:23:38 03/20/09 (0)
  In Reply to: RE: Bille Trouble posted by Shropshire Lad on March 20, 2009 at 21:29:32

  Wait until you get an "official reply" from diyhifisupply before turning on your amp again. Too low filament voltage in filamentary cathode tubes causes premature stripping of your cathode.
  
  

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