WOPL 400 1st time build

[gene french]

last 3 rather...the first one did not...

 

[plex]

Yeah it's been a long day

 

[gene french]

If you think a output may have a bent pin or they were just very hard to line up, then check them against one of the original sockets. The pins were very blunt on the last amp I built compared to the two prior amps. Several outputs needed a little tweek, then no issues.
Also as Joe says, photos. Joe spots issues right away.

after you install a row...check inside that the pins come through the backplanes...that way you know you did not bend a leg...good luch

 

[George S.]

Gene, that's a great idea! Also, only tighten those output bolts until the silpads edge begins to curl or wrinkle, then stop. Yup, tomorrows another day. Later.

 

[plex]

Thanks everyone I will update you tomorrow. Have a good night.

 

[gene french]

Thanks everyone I will update you tomorrow. Have a good night.

use you finger to feel for a ridge that could be cutting the sil pads ..just happened to me ...george suggests w/d sandpaper on you finger to ensure an edge doesnt cut sil pad...

 

[plex]

Good morning. I just wanted to ask if the testing in the bringup instructions is required or if I could just redo the power transistors and check each row with the DBT? Because I don't have the resistors required lying around.

 

[George S.]

Hmm, think that's a question for Joe. Rule #1 don't rush the build.

 

[Gepetto]

Good morning. I just wanted to ask if the testing in the bringup instructions is required or if I could just redo the power transistors and check each row with the DBT? Because I don't have the resistors required lying around.

Peter if you have tested with transistors in the bottom row, you are well beyond any steps that require the resistors you reference except to discharge the bulk caps. You do not want to be doing anything with residual charge of more than ~0.5V in each bulk cap or you will damage things.

 

[plex]

Thanks Joe for the help, and for having patience with this newbie. You're spot on George-I'm rushing.

 

[Gepetto]

Thanks Joe for the help, and for having patience with this newbie. You're spot on George-I'm rushing.

Rushing is a recipe for disaster Peter

 

[Gepetto]

You should also post pictures of your wire up to ensure the careful eyeballs of this forum can steer you away from any other gotchas that may exist

 

[VSAT88]

View attachment 67832
nutria rat...as they are referred to here....and yes, they are quite tasty....
good morning phoenix....
how is the build coming along????

Any Chupacabra round there Gene?

 

[gene french]

Any Chupacabra round there Gene?

no....north as far as panama

 

[gene french]

Any Chupacabra round there Gene?

good to hear from you...i missed you!!!

 

[plex]

Sorry for the large photos. I misplaced my other phone. Will try to take more.

 

[Gepetto]

Sorry for the large photos. I misplaced my other phone. Will try to take more.

The green wire from the copper input jack plate to the bus bar ground between the 2 bulk caps is not required or desired, should be removed. You should be able to temporarily disconnect the shield connections to PAD 2L and 2R and confirm that there is NO CONNECTION of this copper plate to the chassis or to the bulk cap bus bar ground. After confirming that, reattach the shield connections to PAD 2L and 2R

 

[George S.]

With my Variac at 120 VAC output, and a 75 watt bulb in the DBT, my bulb showed a deep orange glow, but no where near white light spectrum. Are you seeing white light?

 

[Gepetto]

With my Variac at 120 VAC output, and a 75 watt bulb in the DBT, my bulb showed a deep orange glow, but no where near white light spectrum. Are you seeing white light?

The glow is mainly from the output bias setting, as you turn the bias down, you will notice the DBT get dimmer.

 

[George S.]

Additional info on the RCA copper plate. Green wire gets removed, coax shields get soldered to plate or RCA grounding tab. RCAs are insulated from the chassis with the fiber washers, copper plate makes contact with both RCAs and coax shields. Hence, the copper plate RCA assembly floats above chassis ground.