phase linear 4000 preamplifier output issue

Joined
Sep 6, 2015
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#1
Hi , anyone in here ever have an issue like this case before ? My preamp was working fine then it is jo sound come up. I check and clean all socket board with contact cleaner. After i just clean up all the board socket with contact cleaning a sound coming back but it's not full output sound. I just turn a volume to 9 o'clock , sound is not loud like before . I turn it maximum sound is just like littlw loud. Anyone know whatis happen ???
 

marcok

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Jun 9, 2014
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#4
Chang ,
you should replace all electrolitic caps .
Since there are more or less 80 / 100 caps start with tone board and logic board .
This is the minimum config to have sound .
Disengage all special functions ( correlator and peak unlimiter ) .
Bp1 and Bp2 have no electrolitic caps .
Ciao
Marco
P.S: i'm talking about PL 4000 series 1
 
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Sep 6, 2015
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#5
thank for your help marcok , finally it's make sound but correct function is not really work well. i just have a current issue now is when i turn a volume nob up or down , it make noise how can i get away with it ? i had try to clean a volume control board but still can not solve this problem.
 

marcok

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Jun 9, 2014
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994
Location
Milan Italy
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I'm very curious about any tech item
#6
Try to clean volume pot .
The volume pot has 2 sections ( one per channel )
One section is easy to clean ( the one near to front panel ) ,
while for the second section there is a small hole on the back of the pot .
Ciao
Marco
 
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#7
All good now , i had ask lee to help me out. He just give me a good advice first step to do is clean all socket and it is true. All issue had been fix. Now i just seat back and enjoy my music.
 
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