Jer's 400 PLWO Thread

[laatsch55]

Jer, I went from 5 to 3 to 1. The ones get tricky if youy slam it on. Bring it up SLOWLY on the variac and you might make it with the 3's. Remember, on a 400 only two rail fuses, + and - on both channels. With Bias at .380 mv,DC wont take much to pinch a 1 amp out.

 

[NavLinear]

Do you use the DBT?

 

[laatsch55]

An .060 socket boss would not have cut it. How much do you lack of comiong to the edge of the heatsink??

 

[laatsch55]

Do you use the DBT?

Yes, in series with the variac.

 

[NavLinear]

Yes, in series with the variac.

Thought so. Maybe pulling the two output fuses first and making sure all else is working well first - IIRC Dr Luicett suggested this in an earlier thread. Thinking out loud. Jer does have some repairs to do but it is looking good.

 

[laatsch55]

Yep he'll get er... Joe and Mark's method is drivers only first then add a pair of outs as you go and check each pair as they are installed.

 

[NavLinear]

Yep he'll get er... Joe and Mark's method is drivers only first then add a pair of outs as you go and check each pair as they are installed.

Baby steps - good for this kind of stuff. Don't want to pull hair out unnecessairly.

 

[laatsch55]

Doon't have much left.

 

[jbeckva]

Do you use the DBT?

Just a Variac. It has an ammeter on the front, so I can watch the current (very carefully) as I dial it up.

Got the left outputs in.. doing the "rights" now... Tempted to work on through to a "power up", but we'll see hehe

 

[Gepetto]

Jer
You have to get rid of that bus wire from the speaker negative terminal and the copper input plate. That bus wire jumper should go between the 2 speaker negatives, not where it is right now. That was a flaw in the single point ground that Phase put in all the PL400 amps.

 

[Gepetto]

And just noticed this too, while you are at it, you have to get rid of the white wire attached to that copper plate. The ground to 5L/R comes from the star point bus bar between the caps to the control board, not from this input location.

Ensure that the RCA shell grounds and that copper plate are isolated from the chassis too.

 

[jbeckva]

Jer
You have to get rid of that bus wire from the speaker negative terminal and the copper input plate. That bus wire jumper should go between the 2 speaker negatives, not where it is right now. That was a flaw in the single point ground that Phase put in all the PL400 amps.

LOL yep figured you would see that. It's on the task list, definitely. Still much to do until we're ready to power it up.

 

[jbeckva]

Outputs "in", new mica insulators and "elephant snot" included... Next - Replacing the input jacks, populating the DCP and getting that in...

(trying me new cellphone cam.. might look a lil funny)

 

[jbeckva]

You guys think I should replace the twisted pair wiring to the RCA's with regular shielded coaxial type??

 

[jbeckva]

Sidenote to Ron.. whoa... all of the old drivers and the majority of the outputs were kaputz! Either blown open junctions or dead short!

 

[jbeckva]

Whoa... (does his best "plumber imitation")

"Where there's ya problem, right there!"

One of the "5A" rail fuses. Errr.. hmm.. actually that's a 30A. Bet somewhere in it's previous life it was at a "gig", and someone went out to their ole car when the music stopped in the middle of it... heheh

We'll be hitting up the "shack" tomorrow for some 5'ers...

 

[Gepetto]

You guys think I should replace the twisted pair wiring to the RCA's with regular shielded coaxial type??

It will not hurt to do so Jer if you have the coax cable

 

[Gepetto]

Whoa... (does his best "plumber imitation")

"Where there's ya problem, right there!"

One of the "5A" rail fuses. Errr.. hmm.. actually that's a 30A. Bet somewhere in it's previous life it was at a "gig", and someone went out to their ole car when the music stopped in the middle of it... heheh

We'll be hitting up the "shack" tomorrow for some 5'ers...

View attachment 8138

Hi Jer
i doubt very much that the shack has the 1" long AGX 5 fuses that you need

 

[jbeckva]

Hi Jer
i doubt very much that the shack has the 1" long AGX 5 fuses that you need

Nah but the western auto does.. one of 'em ought to. Seems that the holders can do up to 1 1/4, since that's what this guy is... but yeah, I did notice it being awful tight getting it twisted out of there.

 

[jbeckva]

Oh Jerrry.......Is there a sticker on the back wall????

(answering kinda late here while I review...)

No, no sticker.. I should put one on - 'stead of Wired by Dart.. hmmm... Wired by Kinda-Getting-There-Old-Fart??

Wired by Dude... how's that?