phase linear 400

gene french

gene french

Veteran and General Yakker
#3,744
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Mar 6, 2022
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guayabo de bagaces, guanacaste, costa rica....
Tagline
music...the healer of souls...
#3,744
parts trickling in ...
i got mr wattsabundant dcp board installed and new input jacks ... thanks again mr. george for the imsulating washers....everything running fine so far...needs a recap...maybe tomorrow....
mr. joes stuff will be here next week...along with the other 8 fin i bought also ...
need to make another order to mr joe .. when i bust open the 8 fin....
really enjoy our music....these systems improve the tv watching sooo much too!!!
almost like being there!!!
 
gene french

gene french

Veteran and General Yakker
#3,745
Joined
Mar 6, 2022
Messages
5,563
Location
guayabo de bagaces, guanacaste, costa rica....
Tagline
music...the healer of souls...
#3,745
ok...one step forward....one backwards...
lol
the original 4 fin...my intro into the pl world... was not making music this morning...it was doing woofer duty....
no blown fuses.....no bright bulb on dbtester....
but the protect board is intermitten....and when it is not on....shows -29v on left channel...not full rail...
i need to do a little research...i am open to suggestions...lol....
so i recapped the first new to me 8 fin...with the bad meters...it is up and doing bass duty now...
no front no top...no bottom...no meters...but, it makes music..
the left and right offset are less than 10mv...i dont remember exactly...and i did not wait for warm up...
.the left bias is at 400mv...wont go lower...
the right bias is at 360....it wont go lower....
playing they both bounce in the 450 mv range...
i did push it over 110 db...for a minute or two...
it has a 14b board that i got from mr. george...
it has an ac hum....but, it is open....no front...no top...no bottom....not shielded....since it was just a dry run....
not too worried about that...i am sure it is a ground loop....
what could be holding the bias up??
both transistors check good out of circuit...and i see nothing obvious....
suggestions??
a pic of the 8 fin after recap...
1671498755382.png
 
mlucitt

mlucitt

Veteran and General Yakker
#3,754
Joined
Jun 24, 2011
Messages
3,479
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Jacksonville, FL
#3,754
gene french said:
this transformer is hotter than all the rest...
registers 83.8 on my new fluke...which i am really enjoying....
Click to expand...
Gene, you have a good transformer there. I remember reading that the original 75V PL400 transformers were wound by Schumacher, the battery charger company still in business today. Their EIA (Electronic Industries Association, until 1997; now the Electronic Industries Alliance) number is 606.
Some days the winder smoked a bit too much grass and over-wound the transformers, I guess. I have seen everything from 77V to 89V in the PL400 amps.
 
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