PL400 glad I found this forum.

gene french

Veteran and General Yakker
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guayabo de bagaces, guanacaste, costa rica....
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music...the healer of souls...
#42
thats the guy that advised you on q1 thru q4...etc
lots of smarts here...
congratulations on progress...
those original ps caps are 50 years old...i upgraded all of mine...got em from gepetto...n9ticable difference in bass....people get hooked on the way the pl sounds...i as many here have spent more hard earned money than we could possibly recover...as with most hobbies ...
its all about the music...
keeping this equipment alive is so rewarding for me...evidently you too...
i also have a smaller system in the bedroom...
 

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GaryCooper

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Apr 28, 2023
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South Central VA.
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X usaf electronic tech.
#46
told ya you could do it!!!
Your faith in me kept me from giving up Gene thank you sir for giving me the support and confidence to keep pushing onward.
And for the rest of you jokers out there .... Thank you also great bunch of guys .

Joe I was really close to trashing this 14a and going WOA. If I find a good deal on another one you will be my first call thank you sir for supporting one of the top brands in history in my opinion.
 

GaryCooper

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South Central VA.
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X usaf electronic tech.
#48
My celebration is cut short seems my 8ohm resistor bank doesnt allow me to test loaded however it does drive a speaker left channel that is , now what i thought was a working right channel now distorts as i turn up input so going to check protection circuit i replaced Q9 but dont have another Q8 1304 pnp. will continue to update so Joe keep an extra WO14 i might be calling lol.
Gene i did get to full power and set bias both channels to 350mvdc , offset still 3.3,3.1
Don I look forward to getting my speaker relay board , I think i need new input post they seem a little weak holding input rca center pin?
 

gene french

Veteran and General Yakker
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guayabo de bagaces, guanacaste, costa rica....
Tagline
music...the healer of souls...
#49
My celebration is cut short seems my 8ohm resistor bank doesnt allow me to test loaded however it does drive a speaker left channel that is , now what i thought was a working right channel now distorts as i turn up input so going to check protection circuit i replaced Q9 but dont have another Q8 1304 pnp. will continue to update so Joe keep an extra WO14 i might be calling lol.
Gene i did get to full power and set bias both channels to 350mvdc , offset still 3.3,3.1
Don I look forward to getting my speaker relay board , I think i need new input post they seem a little weak holding input rca center pin?
i keep throw away speakers just for testing...
my test speakers sound like crap too...they do let me know its workin...my second set of disposible speakers...lol
congrats on the bias and offset...i remember christine was 9mv...both sides...took almost 2 weeks on her...i recapped...ps cap upgrade...also...
i always get the gold plated input jacks for all of mine...old ones are pretty grungy....aling with the plated banana plugs for speakers...new posts come with the dcp board....i actually had a non performing channel...was a corroded jack...thank god i found it before i tore into it!!!
you will definitely enjoy building the wopl...gepetto had it down...only the best of it parts...well documented...and great specs!!!
 
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South Central VA.
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X usaf electronic tech.
#50
so far left channel works good.
right channel is now distorting without hardly any input . so I lifted D9,10 distorsion gone . ok so my 2n1305 hte 103 (spec of 40-200) my 2n1304 hte 78 (spec 40-200) could that difference cause signal failure like that? All the transistors that go together i have replace matched with 3 hte diff max so far the hardest to match were TIS97 they tested low to high so i picked the pairs that matched in the middle. it seems to have paid off with dc offset as low as mine like you said gene under 10 great . I'm waiting on more 1304s hopefully they are higher hte than what i got.

on another note i wonder why my 7.9ohm load bank shuts down the outputs ? is there a need for a capacitor in that circuit ?
 

laatsch55

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Halfbiass...Electron Herder and Backass Woof
#51
No...no cap in your dummy load.

The 1304's and
05's are germanium and read much lower than a silicon. After you pull aleg of D9 and D10 can you go full throttle with no distortion?
If you keep having problems with the 04's and 05's let me know. I have quite a few nos TI's...
 

gene french

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guayabo de bagaces, guanacaste, costa rica....
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music...the healer of souls...
#52
No...no cap in your dummy load.

The 1304's and
05's are germanium and read much lower than a silicon. After you pull aleg of D9 and D10 can you go full throttle with no distortion?
If you keep having problems with the 04's and 05's let me know. I have quite a few nos TI's...
you are a good man charlie brown..
 
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