Johnny D's 700 Adventure

[laatsch55]

Re: Phase Linear 400

Did you complete the re-grounding??

 

[Gepetto]

Re: Phase Linear 400

I think I am going to have to get around to doing a diagram on the grounding Lee and John. Time, such a precious commodity.

 

[soundude]

Re: Phase Linear 400

yes jump 5r and 5L and soldered to buss connecting PS caps and cut the link between the output and input ground...use the volume controls on from of amp, both playing get distortion, turn off left or right channel and distortion goes away..crosstalking some where.

 

[laatsch55]

Re: Phase Linear 400

And as i get older it's going from precious to priceless.

 

[laatsch55]

Re: Phase Linear 400

Hmmmmmm...........................

 

[laatsch55]

Re: Phase Linear 400

that's laatsch55 for I'm thinkin.....

 

[laatsch55]

Re: Phase Linear 400

Are the shields on input to board terminated at both ends?

 

[soundude]

Re: Phase Linear 400

The amp plays excellent but certian frequencies buzz thru the tweeters...trust me its not the speakers...especially piano and guitars. sounds like a leaky transistor or failing cap.

 

[laatsch55]

Re: Phase Linear 400

Didn't think it was the speaks. We're still not out of the woods on this grounding thing. Are the shields terminated at both ends?

 

[soundude]

Re: Phase Linear 400

gonna rip the back plane off and remove all the junk not needed and wire inputs direct and have 2 grounds, one for inputs and one for speakers soldered to buss.

 

[soundude]

Re: Phase Linear 400

gonna go, need a break....pick up on it tomorrow...thxs for the help and tid bits about the grounding. Thxs again laatsch55

 

[laatsch55]

Re: Phase Linear 400

Yep and run separate grounds for each speaker output negative. I know it sounds redundant but there's a good reason for it, but at this moment in time I can't remember, a crown and coke and Patricia Barber in the background.........

 

[laatsch55]

Re: Phase Linear 400

welcome Johnny D.

 

[laatsch55]

Re: Phase Linear 400

Johnny D. Please read this---http://forums.phxaudiotape.com/joe-s-improved-grounding-scheme-t2544.html

 

[soundude]

Re: Phase Linear 400

I will read tomorrow, thx for everything. hear angela walking around must be time for bed.
Good nite, talk to you tomorrow..

 

[laatsch55]

Re: Phase Linear 400

Hookay.

 

[soundude]

Re: Phase Linear 400

laatsch55
How you today?
I removed the binding posts all the wires and rc components and the switch...nice and clean now.
Notice a wire hidden in the back, white w/brown trace that grounds to chassis, connected to ground post of standoffs for the emitter resistor banks. hidden ground I didnt see behind all the r/c crap.
What to change out emitter resistors, what kind are not noisy, metal film or wirewound?
Read the grounding scheme from joes article very educational.
Also where can I get new PS caps without spending over 100 dollars for 2?

 

[laatsch55]

Re: Phase Linear 400

I posted a link tyo Apex jr. 22,000 at 100 volt for 23.95. Build date of b2001, but i'm running a lot of them. They are shown as Adcoms, but are really built by Cornell-Dubilier.
Metal film of the 1% variety is a good choice.
The middle tab of the 3 terminal strips between rows of resistors were Phase's place to chassis ground. they seem fairly benign where they are.
And to your first question--Very Good. Only had to work 10 hours today. Short day.
So the problem is fixed??

 

[laatsch55]

Re: Phase Linear 400

Page 2 of this thread is the Apex link.

 

[laatsch55]

Re: Phase Linear 400

Johnny D. I might add those caps fit the 700 "B"'s LIKE A GLOVE.