I found a PL400II while starting to pack to move. Need a faceplate, anyone have something?

RobertB

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#1
Turns out that I have 3 PL 400's, two original and this series II The first I got has a crazy add on power supply cap board bolted to the cooling fins. Sort of dangerous with exposed wiring. I used it a while then the output got weak (I think, memory is dim). Faceplate on the first one is "acceptable". Not really sure of the operational status of this amp now.

The second one looks great, but burns the power fuse on pluggin in. I used this amp for a while, thought it sounded good. I have contacted WO to get a set of power supply caps for it. Long term plan is to do WO mods to this amp.

I had forgotten about having the series II. I sort of remember getting it on ebay cheap (W/O faceplate) to use for parts. Fired it up, it "works" and can generate decent sound and power, but I don't think it sounds quite as good as it should. I ran it yesterday for a couple of hours feeding Dahlquist Dq-10's. It sure did get hot. Looking in back, quite a collection of different transistors. Starting with a good new matched set might be a good plan for this amp.

The meters don't work correctly on the II. Left one stops at about half power when the amp is producing well over half. The right one stays pegged indicating clipping at any volume level above about 0. Reading the service manual, repair of the original meter boards does not look too difficult. I was monitoring amp power with a Crown OC-150 verified against another 200WPC amp. Looking inside, there is an axial lead capacitor on the back of the right board that is not on the left board, go figure?

Anyone have a faceplate for sale? Any other inputs on my 3 projects are are welcome. BTW, I don't love the PL400II original cosmetics, so a beat up faceplate suitable for painting would be fine with me.

t1.jpg t2.jpg cap.jpg
 

WOPL Sniffer

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#2
The axial cap on the right meter board is there for the rectifier that is on the right board. The right board has the rectifier on it and supplies DC to the left board. It is correct.
 

WOPL Sniffer

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#3
If you cherish your speakers, don't use these amps on them. They are ticking time bombs........
 

RobertB

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#6
Agreed, the new meter board is the way to go. I might spend a little time fooling with the old ones, but probably won't spend much time & $. And yes, a speaker protection board is much cheaper than rebuilding fried speakers! I have one set of speakers fried by an amp, but I think it was a Marantz 250, not the PL400 that killed them. So first priority would be new outputs for sonic improvement and speaker protection board. I can use the Crown meters for now. Thanks for the comments so far.
 

MarkWComer

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#7
If you cherish your speakers, don't use these amps on them. They are ticking time bombs........
Honestly! Try to get a junky pair of speakers from Goodwill just to test for operation.
And make sure your homeowner's policy is paid up in case of FIRE!
 

MarkWComer

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#8
Looking in back, quite a collection of different transistors. Starting with a good new matched set might be a good plan for this amp.

View attachment 36552 View attachment 36553
Good grief, Charlie Brown! That's quite an assortment- someone's definitely fiddled with that sucker.
Baskin Robins 31 varieties of output transistors! Have a look at your control board- bet there's some burn spots on it.
 

MarkWComer

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#9
Phase Linear amps are getting rarer by the hour, to find a replacement face plate is going to be tough. Keep watching ebay, sometimes things turn up that you don't expect. It took forever for me to find a 700/II that didn't look like it was dragged behind a truck, the one I did eventually find had some scuffs that I didn't like. The rubber boots for my turntable suspension eventually turned up, too, but the smaller sized counterweight never did (yet!).
 
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