Kevin's "I Want a Phase Linear 700 B White Oaked" thread

[kevin]

What do ya mean you didnt get much done last night ?? Going to start calling you IRON MAN LEE !!!! I see the time on those post ! I hope your ass is in the bed now ! Looks great Lee... Dont know how you do it !!

 

[speakerman1]

Do you run a sub with the speakers in your avatar?

 

[kevin]

yea... a 15 ... Thats it in the picture.

 

[laatsch55]

What do ya mean you didnt get much done last night ?? Going to start calling you IRON MAN LEE !!!! I see the time on those post ! I hope your ass is in the bed now ! Looks great Lee... Dont know how you do it !!

Up and out by 7:00 AM. Just got in.

 

[laatsch55]

Found some solid evidence for the disparity in the left and right channels. it appears the backside of the PL 020 board was shorted against the common tie point for the left channel positive drive emitter resistors!! Joe ----are you psychic?? The small explosion was intense enough to warrant the replacement of a TO-3 socket, R38, and all emitter resistors on that channel.
Also the left channel Zoebel network is having an identity crisis. The BR will get changed, the power switch, the PS caps (complete with a deluxe model 2 bus bar), AC mains in wiring and fuseholder relocated, in short everything that has shown to improve the sound will be done on this one.

One question Kevin, the volume pots.... we can go about this a couple ways. AND REMEMBER----it's what YOU WANT---not what I prefer. If you want to have the flexibility of retaining the volume controls, I'll p[ut some Alps in. The DC/Normal coupling switch goes, they're garbage. I will give you the option of switching to another set of RCA jacks to totally bypass the pots and go directly to the input pads on the board. What say you??

 

[Gepetto]

Looks like a definite thermal event occurred in there Lee. What did the back of the PL_20 board look like?

 

[laatsch55]

Knew you were gonna ask that, was taking a pic when you posted.

 

[laatsch55]

Notice the pregnant 10 ohm resistor?? Scales out at 22.3

 

[laatsch55]

Ground reference for the input pair and the 20 volt zener is a bad place for that kind of thing. very good reason for limited gain there though.

 

[Gepetto]

For sure, that resistor was ready to give birth Lee. I emailed you a new Timer Bill of Material.

 

[laatsch55]

C23 , the 2.2 @ 35volts reads 14uf. C6 reads 30uf . Q1, Q2 on both channels are KA 1778 's.

C15 reads 5,995 uf ( no, not a typo), C16 reads 9,965 uf. (left channel.)
C11 on each reads in the high 60's.

definately some out of spec components.

 

[laatsch55]

For sure, that resistor was ready to give birth Lee. I emailed you a new Timer Bill of Material.

Sorry Joe, missed this. Thanks, I'll check it out.

 

[laatsch55]

Progress. Tally on the outputs and drivers. There was one output blown in each +/- rail of each channel.

 

[laatsch55]

Houston-------I'm goin down................................chute deployed.............

 

[kevin]

WOW... What a treat ! I get to work this morn and I got all this new stuff to read and all kinds of pics... I love it !!! Now Lee, Let me be real honest ! Guess Ive looked at every pic and read all this stuff at least 5 times. Most of the pics to me look like someone kicked open an old stump and it was full of grand daddy long legs !!!! lmao !! I do see the burned board. O lord yall gonna kick my ass off here one of these days. Lee man I wish I could answer the question you ask me but id be lying if I said I understood. Im just thrilled to death that you are taking the time to do this and how ever you decide to fix it is just GREAT with me... there is no boubt in my mind that you would never send me anything that you wouldnt own yourself !!!!! NOW.... With all that said hurry up and send more pics !!!!

 

[laatsch55]

Gotcha.

 

[mlucitt]

Lee, that is the nastiest 700B I have ever seen. You should put some before and after pictures next to each other. It is a wonder anything was still working in that mess, especially on the + side of the left channel.

 

[laatsch55]

A cherry cosmetically and a mess electrically. Exactly opposite of usual.

 

[soundude]

What a mess is rite, it that the reason they call them flame linears!!
I too am suprise that didnt melt away..
Lee was the micas all burned up in that pic too?
I have to ask did someone put bigger fuses in the rails?

 

[Gepetto]

Those are the ones you hope to find. The innards are easy to fix, the cosmetics are difficult.