PL400

Interesting that a PL700 (not PL700B or PL700 Series II) control board would end up in a PL400, maybe an owner did it? Have we ever seen this before?
Mark, can you upload a picture of the data on the back of the transformer.

Was a stock offering in the very early 400 amps too. Tripod mount. Have encountered probably 6 owners with that board in it Mark over the course of the years I have been offering replacements. They all need the info on where to drill the new hole in the chassis.

I think it was tagged as a PL400C board when installed in the 400.
 
Here are pictures of the board and the back of the transformer.
 

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When I receive it a couple of months ago I looked it over and it was my opinion that it was all original. If it wasn’t it was not obvious.
 
It's probably the same as mine was. It also had 3 adjustment pots per channel.
 

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Was a stock offering in the very early 400 amps too. Tripod mount. Have encountered probably 6 owners with that board in it Mark over the course of the years I have been offering replacements. They all need the info on where to drill the new hole in the chassis.

I think it was tagged as a PL400C board when installed in the 400.

Yep, I did one back when I was doing amps. Might be this 400 I have up now, can't remember shit.
 
I haven't seen one like Mark's, I've seen one like Punch's...

Mark, the adjustment procedure should be the same......nice work on the board....
 
Production of the PL400 started in December of 1971. According to the PL records concerning S/N 442-012, your PL400 was made in April of 1972. The one you have was #12 out of however many they built that month. The average in 1972 was about 250 PL400 amplifiers per month. Your amplifier could be among the first 1000 made.
 
I thought it might be an early one. I need to get it on a dim bulb tester and see where it takes me. I’ll post back in a day or so. Have to go to Louisville Ky tomorrow. Thanks for all the help.
 
I have been thinking about the comments and advice given by each of you and have decided to go with the White Oak
Board. Seems this might be best considering the time/money factor together with sound quality and reliability issues.
When I get the board assembled and installed I’ll be back here for an update and/or further advice. Thanks again for all your help.
 
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