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WAD Problems For questions and answers re older World Audio Design Projects

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  #11  
Old 22nd January 2021, 08:23 AM
Richard Richard is offline
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Default Re: Big trouble with Pre Phono 2

All the "valves" are really 2 valves so you cannot isolate one even in the case of V4a/b (possible but unlikely both sections would fail in a similar way). A better way is to change all the valves for known good valves. If the valves are old originals it could be more than one of the valves are becoming weak.
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  #12  
Old 22nd January 2021, 08:38 AM
bob orbell bob orbell is offline
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Default Re: Big trouble with Pre Phono 2

looking at the first picture, I wonder if those large blocking capacitors are touching the output pins, or, the bare wire connecting the capacitors. Bob
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  #13  
Old 22nd January 2021, 07:49 PM
LSfarzo LSfarzo is offline
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Default Re: Big trouble with Pre Phono 2

I will be out of my home for a week, due to work. I'll be back on the end of jab. Then I will change the valves with a brand new triplet for testing purposes, to be sure they work (or at least they should !).
Now I am using 3 x 12aX7 Electro Harmonix, since about 2003,

Second, will double check every pin in case of accidental touching, but i
would consider this pretty unlikely.. anyway better do not leave nothing checked.

Thanks everybody for your precious support !!!

Luca
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