phase linear 400

Gepetto

Gepetto

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Sunnbobb said:
This amp came with four 66546's as output drivers on the bottom row, and the rest of the transistors were B05's. of which 3 were bad. I have a set of 10 15025's I'd like to use, I need two more. I have removed all the B05's.. I tested the 66546's, installed them, and the DBT is behaving. Now I need to populate the rest of the transistors. Thanks for the offer!
Click to expand...
15025s are PNPs and are not to be used in quasi-comp amps...
 
Sunnbobb

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LOL, major brain lock. I had the bag side by side with the bag of TP9054's. It's the 9054 that I have 10 of, and need two more. Thanks for the catch. And if anyone needs 15025's, LMK.
 
gene french

gene french

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got started today on the white oak control board upgrade for christine (the evil one)...no need to hurry...its just a spare...not sure how this happened, but i had a wopl subdirectory on the big computer with all documentation in it ...it is gone...no idea...wrote to joe as his website has no docs to download .... christine already has ps cap upgrade ...rectifier upgrade and light board upgrade...will also change outputs to 410s/msgjibvfd96s...as i bought them earlier ... with new sil pads...should be running in the not too distant future...if the crik dont rise...
 

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Sunnbobb

Sunnbobb

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Ya hey gang. I have another stump the Sunnbobb issue. I'm working on an pl400 with the PL14 Board. I haven't found anything in the service manual that deals with this issue.
Using a DBT and a variac, with no out puts, the amp fires up fine. With just the DBT, and fired up hard from 110V, the bulb lights up and dims immediately as it should.
If I connect my test speakers up (output), and fire up the amp, the DBT glows very bright, and remains on. It does the same even if I only hook one speaker up on either output.
All transistors test fine. 401 predrivers, and MJ96 drivers in correct positions on the back plane.
I replaced the Filter caps with new ones from WO, as well as the WO Bridge rectifier.
All new fuses, and none are blowing.
DC offset is less than .04 on the left channel, and .01 on the right, well within spec.
Bias is running at 4.9 MV, again, not far from spec.
The filters caps and rails are running at about 79V.
I did these tests without the speakers hooked up as I did not want to run the amp with the DBT bright.
Lastly, the Q3 and Q4 are the recommended MPS A93.
 
Gepetto

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Sunnbobb said:
Ya hey gang. I have another stump the Sunnbobb issue. I'm working on an pl400 with the PL14 Board. I haven't found anything in the service manual that deals with this issue.
Using a DBT and a variac, with no out puts, the amp fires up fine. With just the DBT, and fired up hard from 110V, the bulb lights up and dims immediately as it should.
If I connect my test speakers up (output), and fire up the amp, the DBT glows very bright, and remains on. It does the same even if I only hook one speaker up on either output.
All transistors test fine. 401 predrivers, and MJ96 drivers in correct positions on the back plane.
I replaced the Filter caps with new ones from WO, as well as the WO Bridge rectifier.
All new fuses, and none are blowing.
DC offset is less than .04 on the left channel, and .01 on the right, well within spec.
Bias is running at 4.9 MV, again, not far from spec.
The filters caps and rails are running at about 79V.
I did these tests without the speakers hooked up as I did not want to run the amp with the DBT bright.
Lastly, the Q3 and Q4 are the recommended MPS A93.
Click to expand...
Hi Richard
Bias is running at what level??? "Bias is running at 4.9 MV, again, not far from spec."
 
gene french

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#4,480
Sunnbobb said:
Ya hey gang. I have another stump the Sunnbobb issue. I'm working on an pl400 with the PL14 Board. I haven't found anything in the service manual that deals with this issue.
Using a DBT and a variac, with no out puts, the amp fires up fine. With just the DBT, and fired up hard from 110V, the bulb lights up and dims immediately as it should.
If I connect my test speakers up (output), and fire up the amp, the DBT glows very bright, and remains on. It does the same even if I only hook one speaker up on either output.
All transistors test fine. 401 predrivers, and MJ96 drivers in correct positions on the back plane.
I replaced the Filter caps with new ones from WO, as well as the WO Bridge rectifier.
All new fuses, and none are blowing.
DC offset is less than .04 on the left channel, and .01 on the right, well within spec.
Bias is running at 4.9 MV, again, not far from spec.
The filters caps and rails are running at about 79V.
I did these tests without the speakers hooked up as I did not want to run the amp with the DBT bright.
Lastly, the Q3 and Q4 are the recommended MPS A93.
Click to expand...
thats the same setup i am using in christine...
i replaced my pl14s...could not fix them...too rough...
got the white oak control board...
outputs are rca 410s with mj96s...
i have the 410s installed and one row of 96s...
i want to bring it up this way....
i think i am ready to fire up tomorrow...
want to reread the bring up procedures again...
now that i have the files...
lol
 
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