James Burkes Phase Linear 400 Ser I

[laatsch55]

This was dropped off on his way through on vacation to So. Dak. Originally for Joe's cap kit. He acquiessed to a Don Imlay DC protect board, but there are certain things I just can't leave alone, like 2N5401's in Q1,2--MPSA 5172's in Q3,4-- DC offset was 34mv left side, 35mv right side. Bias 365mv left, 395 right. Diostortion is pretty bad on the left side hitting greater than 1% below 20Hz. Caps have been replaced recently by Soundsmith, Had to break those little seals that say-"Warranty void if seal broken" I just love doing that. He's due back through Monday or Tuesday, better get busy.

 

[laatsch55]

A sick little 400....................

 

[Gepetto]

He needs to White Oak this amp Lee

 

[laatsch55]

I know Joe. Limited budgets are a killer. What caps have an "M" for their make?? I'll see if I can get a pic. Ya know for as much time as I'd have bringing his board up to spec, I could have put a Joe board together. He's pretty active in the Portland area, maybe I should do it from a promotional standpoint.

 

[Gepetto]

The one I am familiar with Lee is Panasonic. The Panasonic ones that I use for the 6800uF in the cap stack has an M on it, is that what you are referring to? Or something else? Possibly the reason that they do this is that it was an acquisition by Panasonic and they kept the mark??

 

[laatsch55]

They look like an FC or FM but have NHG asa series number. BTW, just unpacked your cap-kit. They're lookin better all the time. Quadrupling the uf in one fell swoop, not a bad thing.

 

[Gepetto]

The caps with the M that has the bottom of both legs curling inward toward the center of the M are Panasonic Lee. No clue on the light blue encased ones.

 

[laatsch55]

Notice the 33uf in C3?

 

[Gepetto]

Oh well, it's hard to get good help these days

 

[laatsch55]

The thread lock Phase used was some good stuff. The phillips pattern gave out and had to slot the screws to get a good enough grip, 2 of the 4 broke. This amp appears to have smoked at on time. thgose aren't dust stains, they're smoke stains.


What's even scarier---- no turn off thump, maybe a kerfluffle.

 

[laatsch55]

To White Oak or not to White Oak, that is the question.

 

[laatsch55]

Silly question wasn't it??

 

[laatsch55]

1/4 watt in.

 

[Gepetto]

He's goin in folks

 

[Gepetto]

Probably easier than debugging the problem with the original board...

 

[Skratch]

Going to get noisy in Gillette tonight ?????

 

[laatsch55]

Well of course!! No problem with the board Joe, other than rep[lacing most of the caps and transistors, and if I'm gonna do that............................ he goes in..........................

 

[mlucitt]

Maybe tomorrow Lee will be done. There are 205 parts requiring 385 solder connections on these boards (if I counted correctly). Even though Lee and I have perfect vision (right?), it takes a few sessions, so the eyeballs can rest. I think Lee holds the record, it takes me about 7 hours to put one together. This included verifying each component, pre-bending the leads, and cleaning the rosin off the board.

Mark

 

[laatsch55]

3-1/2 hours average Mark.

 

[laatsch55]

Done.........