phase linear 400

gene french

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#21
btw...while i am here...i am restoring a pioneer sx1080 also...and i need one (or two...for a spare) 2sd737 transistor...they are very hard to find...i did find one nos...but, still need another to get through with that one....this vintage stuff is expensive and hard to find...but, sure is a lot of fun...
 

laatsch55

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#23





  • markthefixer Off Hiatus, overwhelmed BUT STILL doing Clutches Subscriber

    Messages: 23,210 Location: Bensenville,Illinois




    The Q5 & Q6 drivers 2sb536a & 2sd381 are ~ 30 MHz, with 330 pf neutralization caps collector to base
    which will severely cut any high speeds, so I strongly suspect that you will just need to match voltage (160v), current (12A) & power(120W) requirements,
    because I couldn't find 2sb701a & 2sd737a 's Ft! (maybe 10 MHz)

    Paralleled outputs should be similar in Vbe - Volts base to emitter , so that there is equitable sharing of the load. One or the other output transistor will not be working as hard.

    And the only real indicator of THAT is to look at EACH of their emitter currents (voltage across each of the 0.5 ohm emitter resistors) during idle.

    Remember - the only penalty of slightly increased idle current is heat, whereas too low of an idle current generates distortion.



    Last edited: Jul 11, 2020

 

gene french

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#27
A DC protect board from wattsabundant (,Don Imlay) is highly recommended. Especially with the old outputs you are running.
i wrote to the gentlemen on his website about how to obtain one....awaiting his response
i wrote to white oak about the cap upgrade and the board upgrade....awaiting his response...
thanks so much!!!!
 

laatsch55

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#28
Don's day job takes him all over the country. It can be a few days sometimes before he can get back to ya. White Oak Joe can get buried at times too...patience..
 

Gepetto

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#32
not yet...i couldnt help myself...its hooked up and running....plays perfectly....
i think i will order the protect circuit and big caps first...
not sure if the white oak board will work in mine...they have not answered my email about that...
i have the 400c board according to the service manual layout...
Works in every 400 and 700 Gene
 

gene french

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#33
Works in every 400 and 700 Gene
thank you so much....i appreciate your time...and good to know...
the faqs state that the kit does not work in the very early 400s...that is what had me worried....

"Does the PL400 Capacitor Upgrade Kit work in all Phase Linear 400 Amplifiers?
It works in all but the earliest PL400s. The earliest PL400s produced had the power supply capacitors mounted directly to the left side of the amplifier chassis using 2 round capacitor brackets. The rectifier bridge was also mounted to the chassis side in this amplifier vintage. The White Oak Audio Capacitor upgrade WILL NOT install in amps of this vintage. "

my 400 fits that description....
and i just wanted to make sure that the kits will all work in my 400....i am a long way away ... better safe than sorry...
take care...
gene

ps...how do i order and pay for these kits???
 

Gepetto

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#34
thank you so much....i appreciate your time...and good to know...
the faqs state that the kit does not work in the very early 400s...that is what had me worried....

"Does the PL400 Capacitor Upgrade Kit work in all Phase Linear 400 Amplifiers?
It works in all but the earliest PL400s. The earliest PL400s produced had the power supply capacitors mounted directly to the left side of the amplifier chassis using 2 round capacitor brackets. The rectifier bridge was also mounted to the chassis side in this amplifier vintage. The White Oak Audio Capacitor upgrade WILL NOT install in amps of this vintage. "

my 400 fits that description....
and i just wanted to make sure that the kits will all work in my 400....i am a long way away ... better safe than sorry...
take care...
gene

ps...how do i order and pay for these kits???
Yes, we have a cap kit for that version
 

gene french

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#35
hey guys...please help me out...i just got a list of equipment from joe at wo...
i dont understand the terminology....please explain it to me...i am sure joe thinks i am an idiot....
well, maybe...lol
which board is this one that i have??
what is the pl14 boards??
what is a backplane ??
according to the service manual i have a 400c board and not pl14x...
please forgive my ignorance...phase linear is new to me...
and when you explain it...i will no longer be a dumb a**....
and maybe i can hang out in the big boy forums...
thanks for your help...
gene
 

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George S.

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#36
hey guys...please help me out...i just got a list of equipment from joe at wo...
i dont understand the terminology....please explain it to me...i am sure joe thinks i am an idiot....
well, maybe...lol
which board is this one that i have??
what is the pl14 boards??
what is a backplane ??
according to the service manual i have a 400c board and not pl14x...
please forgive my ignorance...phase linear is new to me...
and when you explain it...i will no longer be a dumb a**....
and maybe i can hang out in the big boy forums...
thanks for your help...
gene
Read my thread PL 700 Pro-build https://forums.phxaudiotape.com/threads/pl-700-pro-build.9965/.
I documented the build to help the new guys. Lots of photos to check out. The thread meanders some, but you'll see photos of the White Oak Products.
A 400 is much easier to build than a 700, so don't be intimidated.
Then peruse the Forum category "WOPL Building". Lots of good info and photos there. WOPL means White Oak Phase Linear.
Have fun, it's a fantastic hobby!
 
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