NEW PL700 Series 2 WOPL BUILD

Greg

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#48
Re WOPL Build for a PL700 series 2 is there a specific build pattern and key notes to focus on I am keeping the original ( Ill call it Back plane ) main transistor assembly intact as is and just wish to implement the WOPL build to replace the original PL36 board
 

George S.

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#49
Original PL backWALLS came in two configurations, complementary or quasi-complementary. Probably 95% or greater of 400 and 700s are quasi, and the end of production units are complementary.
If you install the WOAD backPLANE, this is complementary only. The WOAD control board can be built configured for quasi or complementary.
I suggest you WOPL the entire unit and add Don's DCP output relay board.
Easy to tell if your unit is quasi or not by looking at the output configuration with the transistor covers off. Post a photo of the rear if you have questions.
 

George S.

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#50
At the minimum, you'll want new storage caps, control board kit or prebuilt control board, and DCP.
Joe will email you PDF files for installing the board.
I myself tend to over build things so they last with no maintenance issues. That's why all three of my amps are full WOPL with 100% mil-spec silver plated Teflon insulated wiring.
But, there are quite a few guys that keep the stock units going. Really no right or wrong in what you decide. Having choices is a good thing!
 

e30m3mon

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#51
At the minimum, you'll want new storage caps, control board kit or prebuilt control board, and DCP.
Joe will email you PDF files for installing the board.
I myself tend to over build things so they last with no maintenance issues. That's why all three of my amps are full WOPL with 100% mil-spec silver plated Teflon insulated wiring.
But, there are quite a few guys that keep the stock units going. Really no right or wrong in what you decide. Having choices is a good thing!
And be sure to get the wiring kit that works with the backplane upgrade...that teflon wire George mentions above is worth every penny spent.

If you go full-compliment (recommended) you'll likely need new transistors too.

As George said, build it once ... build it right. I have no regrets doing mine 2 years ago and am about to start a full build for a friend's 400-II. I want to keep his friendship ;)
Get the correct Kester solder too; Joe will recommend the good stuff.
Good luck.
 

gene french

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#52
At the minimum, you'll want new storage caps, control board kit or prebuilt control board, and DCP.
Joe will email you PDF files for installing the board.
I myself tend to over build things so they last with no maintenance issues. That's why all three of my amps are full WOPL with 100% mil-spec silver plated Teflon insulated wiring.
But, there are quite a few guys that keep the stock units going. Really no right or wrong in what you decide. Having choices is a good thing!
to quote the infamous bob ross...there are no mistakes...just happy accidents...lol
 

Gepetto

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#53
Original PL backWALLS came in two configurations, complementary or quasi-complementary. Probably 95% or greater of 400 and 700s are quasi, and the end of production units are complementary.
If you install the WOAD backPLANE, this is complementary only. The WOAD control board can be built configured for quasi or complementary.
I suggest you WOPL the entire unit and add Don's DCP output relay board.
Easy to tell if your unit is quasi or not by looking at the output configuration with the transistor covers off. Post a photo of the rear if you have questions.
>99.5% quasi
 

Gepetto

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#54
Your soundstage and sound quality will be much improved going full comp vs leaving it quasi comp. That is why we do that critical conversion...

There is zero value in preserving a stock PL amplifier. It is a mistake to think that there is.
 

Greg

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Messages
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#56
Original PL backWALLS came in two configurations, complementary or quasi-complementary. Probably 95% or greater of 400 and 700s are quasi, and the end of production units are complementary.
If you install the WOAD backPLANE, this is complementary only. The WOAD control board can be built configured for quasi or complementary.
I suggest you WOPL the entire unit and add Don's DCP output relay board.
Easy to tell if your unit is quasi or not by looking at the output configuration with the transistor covers off. Post a photo of the rear if you have questions.
7D0E911C-FF69-4DA5-9EFB-87CB09231C3F.jpeg 2BFECC8C-B154-40A4-BD1A-C90ED7970971.jpeg F54EC53C-DBF4-4D6F-AC69-2C17F4EC06F4.jpeg E6689D4A-D716-4D00-8E73-ED1F2769B336.jpeg
 

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Greg

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Jun 11, 2022
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#59
BTW those NEC transistors are pretty awful devices
Lol is a mess This is the unit that I have purchased the WOPL kit and caps and transistors for from you ... I hope I ordered right lol ! I had sent you some pics Thx Joe !
 
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