First PL700 Check Out

Kma4444

Journeyman
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Feb 8, 2020
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Alright so this is the 1st of my inherited amps getting a very basic check out. I attached a video, at least I hope I will, of the DBT, just so someone can say normal or otherwise. And then pics just because. I think dad bought this new as he engraved his name and SSN on the side.
It was missing the cap for the lower right supply fuse, I think I identified that correctly. When I replaced it the right channel had -85 vdc. The left had .125 vdc. I originally powered it up with the variac slowly, took about a minute as suggested here.
So I'm assuming this was taken out of service for the problem with the right channel. What would I do from here, besides a total rebuild with White Oak bits. I want to do that with some if not all of these but it would be cool to get one working while I am doing others.
Thank you IMG_20200525_131957.jpgIMG_20200525_132016.jpgIMG_20200525_132458.jpgIMG_20200525_133442.jpgIMG_20200525_133454.jpgIMG_20200525_133625.jpgIMG_20200525_133627.jpgIMG_20200525_133631.jpgIMG_20200525_133636.jpgIMG_20200525_133737.jpg
 
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Failed DBT. Left meter up half way also. Experts will be along soon but sounds like a shorted output. Was the 85v + or - will help you narrow things down.
 
Thank you very much. I decided to go ahead and check out some of the other ones. The second one I will show here, and it illustrated the difference in the DBT test for me.
I'm guessing this test was more normal. But this one shows +95.2 vdc on the left and .062 on the right.
This amp is really clean and nice looking to my untrained eyes. IMG_20200525_142613.jpgIMG_20200525_142750.jpgIMG_20200525_142753.jpgIMG_20200525_142755.jpgIMG_20200525_142757.jpgIMG_20200525_142800.jpgIMG_20200525_142814.jpgIMG_20200525_142818.jpgIMG_20200525_142826.jpg
 
I need to look and see, I know I got one book but not sure if it was owners or service.
 
So here's the 3rd for today. This is the one that I earlier powered up with the variac and then tried to play sound. It seemed like it was working alright, only had one speaker hooked up. Then it blew the line fuse. You can see the dcv test on the tape on top of it.
The DBT test seems fine. IMG_20200525_150533.jpgIMG_20200525_150529.jpgIMG_20200525_150527.jpgIMG_20200525_150526.jpgIMG_20200525_150523.jpgIMG_20200525_150440.jpgIMG_20200525_150434.jpgIMG_20200525_144030.jpg
 
Last 700 of my collection. This one is pretty rough looking. Seems to fail the DBT. Output dcv look OK I think.
Off to put my hands on the manual I have. IMG_20200525_152006.jpgIMG_20200525_152137.jpgIMG_20200525_152145.jpgIMG_20200525_152206.jpgIMG_20200525_152210.jpgIMG_20200525_152212.jpgIMG_20200525_152214.jpgIMG_20200525_152217.jpgIMG_20200525_152221.jpgIMG_20200525_152243.jpg
 
So here's the 3rd for today. This is the one that I earlier powered up with the variac and then tried to play sound. It seemed like it was working alright, only had one speaker hooked up. Then it blew the line fuse. You can see the dcv test on the tape on top of it.
The DBT test seems fine. View attachment 42337View attachment 42338View attachment 42339View attachment 42340View attachment 42341View attachment 42342View attachment 42343View attachment 42344
Bottom row on the outputs should be 410's , they are all the same 15024's
 
Last 700 of my collection. This one is pretty rough looking. Seems to fail the DBT. Output dcv look OK I think.
Off to put my hands on the manual I have. View attachment 42346View attachment 42347View attachment 42348View attachment 42349View attachment 42350View attachment 42351View attachment 42352View attachment 42353View attachment 42354View attachment 42355


Pretty rough lookin outputs, the 410's should be in the bottom row, all other outputs on each channel should be the same..909's, or 15024's or 2SD 555's..
 
Pretty rough lookin outputs, the 410's should be in the bottom row, all other outputs on each channel should be the same..909's, or 15024's or 2SD 555's..
Thank You, much of this one looks pretty rough. Looks like it bounced in it's past also. Chassis is bent etc....
 
I'm not trying to bombard the board with stuff, just figured since I was checking one out I would do them all. I will do the 400s next. It seems I just have the owner's manual. Can't imagine dad didn't have the service manual but I haven't come across them yet. Where does one get them? Suppose I will need 700, 700B and 400.
 
Failed DBT. Left meter up half way also. Experts will be along soon but sounds like a shorted output. Was the 85v + or - will help you narrow things down.
I added the - to the vdc number where needed. I think it's poor lighting in my video, I don't think the left needle was up.
Thank you again
 
700, 700B should be the same manual. 400 should be it's own. The Ser II's will be a separate manual also...

Try Hi-Fi Engine.

But if you want a good hi quality copy Stereomanuals.com
 
I'm not trying to bombard the board with stuff, just figured since I was checking one out I would do them all. I will do the 400s next. It seems I just have the owner's manual. Can't imagine dad didn't have the service manual but I haven't come across them yet. Where does one get them? Suppose I will need 700, 700B and 400.
You do NOT need to apologize for posting pictures of PL gear on this board!
You have a lot of good iron there and the people on this board are just as interested as you are in getting them all in working condition. I might make a suggestion - because you can't listen to all those amps at once, you may consider selling one or two to pay for the bits you will need to make the rest of them operational and reliable. Figure $300 to $600 per amp to make them worth twice that much after the upgrades. And you will learn a lot in the process. You are what keeps this board going.
 
Last 700 of my collection. This one is pretty rough looking. Seems to fail the DBT. Output dcv look OK I think.
Off to put my hands on the manual I have. View attachment 42346View attachment 42347View attachment 42348View attachment 42349View attachment 42350View attachment 42351View attachment 42352View attachment 42353View attachment 42354View attachment 42355
Never seen a heatsink bent like that. Usually the chassis ears. Joe can take care of you. We always enjoy seeing 700's coming back to life. Happy dance time.
 
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