Phase Linear 400 issue help!

[laatsch55]

To improve what you already have in that PL14 board, C6 needs to be swapped out with a 470uf/25 or 50 volt audio grade cap. Nichicon KZ "Muse" or Elna "Silmic II's". Then take 2 1N4148 diodes , put them back to back and reversed to each other and soldered accross the leads of C6 on the backside of the board. See pic..

 

[enoyes12]

Looks like it says ndo or ndb imprinted inside the board. pic is upsidedown

 

[enoyes12]

That's a little dust that the flash highlighted. I haven't cleaned and blown out the inside yet

 

[enoyes12]

Mold, are you kidding? I'm in Phoenix AZ, with 10% humidity and a "dry heat" even mold thinks it's to damn hot here!! LOL

 

[laatsch55]

I'm there for a week or 10 days every January. We'll have to tag up when I'm down there next.

 

[enoyes12]

Absolutely, I'm in north Phoenix.

 

[laatsch55]

East or west of 17?

 

[enoyes12]

west

 

[laatsch55]

Daughter lives in Surprise right off of Dysart near Waddell.

 

[laatsch55]

OK, whats up with the username, gotta be a story behind that...

 

[enoyes12]

just my initial and last name

 

[enoyes12]

Shes about 20-25 minutes from me

 

[laatsch55]

That's where we stay when down there.

 

[NavLinear]

I replaced the electrolytics yesterday. Are there any others I should replace?

You changed out the nine electrolytic capacitors on the controller board including C6 and C3? Any audible changes?

 

[enoyes12]

Hard to tell but by ear it sounds better. Heading to get the parts mentioned earlier. I'll do one thing at a time and let you know how it goes.

 

[laatsch55]

The 470uf at C6 will lower the low frequency response considerably.....You'll definately notice a change..

 

[enoyes12]

quick question. the service manual calls for four .01/1000v mylar or ceramic caps on the rectifier. Why does the voltage need to be so high?

 

[laatsch55]

There's a voltage swing of 160 volts on the DC end and then 120 on the AC end, Plus turn on transients, and peak voltages. 400 volt are fine..

 

[laatsch55]

You want self healing polypropylene caps there.....

 

[enoyes12]

Well the 400v part is good because they didn't have them in 1000v. I don't know if they have the poly self healing either, I only saw ceramics, mylar and electrolytic. Typical all the good component suppliers by me are gone. People need to start fixing their $hit instead of buying new all the time! Where can I get them, Mouser?