Resurrected a Customized WOPL 400

scottonnob

scottonnob

Journeyman
#42
Joined
Apr 28, 2015
Messages
251
Tagline
---
#42
I'm not sure I understand. I ran the black wire from the rectifier. Is it in the wrong place or on the wrong post?
 
laatsch55

laatsch55

Administrator,
Staff member
#43
Joined
Jan 14, 2011
Messages
74,874
Location
Gillette, Wyo.
Tagline
Halfbiass...Electron Herder and Backass Woof
#43
The DCP requires an AC feed from the rectifier, a DC feed from the + rail, and a Star ground. The wire from the rectifier has to be from an AC post, not the DC posts....
 
scottonnob

scottonnob

Journeyman
#44
Joined
Apr 28, 2015
Messages
251
Tagline
---
#44
laatsch55 said:
The DCP requires an AC feed from the rectifier, a DC feed from the + rail, and a Star ground. The wire from the rectifier has to be from an AC post, not the DC posts....
Click to expand...
So I need to run a wire from the other post that feeds the capacitors, a wire from both sides of the rectifier?
 
laatsch55

laatsch55

Administrator,
Staff member
#45
Joined
Jan 14, 2011
Messages
74,874
Location
Gillette, Wyo.
Tagline
Halfbiass...Electron Herder and Backass Woof
#45
No, you need to move it to one of the posts where the transformer secondaries is soldered to...
 
laatsch55

laatsch55

Administrator,
Staff member
#47
Joined
Jan 14, 2011
Messages
74,874
Location
Gillette, Wyo.
Tagline
Halfbiass...Electron Herder and Backass Woof
#47
Yep, and the Star ground and From the DC+ rail feed from the backplane. Have you been to wattsabundant website and downloaded the installation instructions??
 
scottonnob

scottonnob

Journeyman
#48
Joined
Apr 28, 2015
Messages
251
Tagline
---
#48
laatsch55 said:
Yep, and the Star ground and From the DC+ rail feed from the backplane. Have you been to wattsabundant website and downloaded the installation instructions??
Click to expand...
Okay, I went to the website and reviewed the installation material. From what I can see, the only problem is that I attached the AC lead to the wrong post on the rectifier. My white ground wire is soldered to the buss between the capacitors. Am I still missing something?
 
scottonnob

scottonnob

Journeyman
#49
Joined
Apr 28, 2015
Messages
251
Tagline
---
#49
From Joe's installation material, I understand that the DC source will come from the right channel B+ out on the backplane board. I'm just trying to get to the point of installing the caps. But I don't want to do so until I'm through attaching any wires in the general area.
 
laatsch55

laatsch55

Administrator,
Staff member
#50
Joined
Jan 14, 2011
Messages
74,874
Location
Gillette, Wyo.
Tagline
Halfbiass...Electron Herder and Backass Woof
#50
scottonnob said:
Okay, I went to the website and reviewed the installation material. From what I can see, the only problem is that I attached the AC lead to the wrong post on the rectifier. My white ground wire is soldered to the buss between the capacitors. Am I still missing something?
Click to expand...
Nope, ya got it now...
 
scottonnob

scottonnob

Journeyman
#51
Joined
Apr 28, 2015
Messages
251
Tagline
---
#51
The funny thing is, when I looked at the drawing I made before I did the soldering, I had instructed myself to attach the AC for the relay to the correct post. Brain fart. But now that part of the project is all wired up. And barring identification of some mistake I've made, it's now time to focus my attention to the rear of the chassis and begin the odyssey of the transistors. Would you agree?

I had to substitute one of the old capacitor holders because the fuse holder I bought is longer than the original. The cap wouldn't fit into the ring of the new holder. It was blocked by the fuse holder. But putting the old capacitor holder in and using some hard rubber as a shim worked fine.

WOAPL Buildout — 16.jpg WOAPL Buildout — 17.jpg
 
scottonnob

scottonnob

Journeyman
#53
Joined
Apr 28, 2015
Messages
251
Tagline
---
#53
From Joe's instructions, it looks like bringing up the first transistors is pretty straight forward. However, I'd feel better if there was a thread that walks a guy through the process. Does anyone know of such a thread, or have some related information? I could swear I looked at something somewhere that had more detailed instructions. But it could just be my imagination.
 
scottonnob

scottonnob

Journeyman
#55
Joined
Apr 28, 2015
Messages
251
Tagline
---
#55
laatsch55 said:
You've got the backplanes and control board in?
Click to expand...
The backplanes are in. I'm still waiting for the control board. Joe said he's pretty busy. I'm sure he'll get to me when he can. But I'm referring to the instructions that come with the backplane kit. It says to install the first row of drivers and Variac and so forth. Am I mistaken, regarding the next step?
 
Gepetto

Gepetto

Administrator
Staff member
#56
Joined
May 15, 2011
Messages
14,008
Location
Sterling, MA
Tagline
Old 'Arn Enthusiast
#56
scottonnob said:
The backplanes are in. I'm still waiting for the control board. Joe said he's pretty busy. I'm sure he'll get to me when he can. But I'm referring to the instructions that come with the backplane kit. It says to install the first row of drivers and Variac and so forth. Am I mistaken, regarding the next step?
Click to expand...
You are not mistaken Scott. Check out the backplanes using that bring up procedure.
 
scottonnob

scottonnob

Journeyman
#57
Joined
Apr 28, 2015
Messages
251
Tagline
---
#57
Gepetto said:
You are not mistaken Scott. Check out the backplanes using that bring up procedure.
Click to expand...
Okay, thanks. But is there any source you know of that has any more information on the procedure. For obvious reasons, I'm a bit anxious about putting power to anything for the first time.
 
Gepetto

Gepetto

Administrator
Staff member
#58
Joined
May 15, 2011
Messages
14,008
Location
Sterling, MA
Tagline
Old 'Arn Enthusiast
#58
scottonnob said:
Okay, thanks. But is there any source you know of that has any more information on the procedure. For obvious reasons, I'm a bit anxious about putting power to anything for the first time.
Click to expand...
This is pretty specific Scott.

With the connections to the control board all taped offso they do not short out to anything (both the bottom row of 10 wires and 3bias connection wires per channel).
Install the bottom row of transistors starting from the transformer, NPN, PNP,NPN, PNP. Remove the one wire to the upper left backplane 6-32 screw byremoving the securing nut and floating this wire in the air. Install railfuses. Check for infinite resistance between chassis groundand the transformer cases. If not debug. (you will get a readingbetween DC ground bus bar and these cases, you meter will be charging up thebulk caps)
Connect a ~10K resistor between the output and ground test point on eachbackplane.
Install rail fuses
Bring up on DBT and Variac to 60VAC in on the AC input. Make sure all isgood and no smoke is coming out. Measure that you have B+ and B- voltagespresent at the respective test points and B- at PAD12 and B+ at PAD 11 on eachback plane board.

Check that you have 0V at the output test point.

Take the Variac all the way up and repeat.

Next, before doing anything else, power the amp down and fully DISCHARGE thebulk caps using a 1K 2W resistor (any value close to 1K will do) down to alevel below 1V.

Then you are good to proceed to the next assembly step if this is all good.
 
scottonnob

scottonnob

Journeyman
#59
Joined
Apr 28, 2015
Messages
251
Tagline
---
#59
Gepetto said:
This is pretty specific Scott.

With the connections to the control board all taped offso they do not short out to anything (both the bottom row of 10 wires and 3bias connection wires per channel).
Install the bottom row of transistors starting from the transformer, NPN, PNP,NPN, PNP. Remove the one wire to the upper left backplane 6-32 screw byremoving the securing nut and floating this wire in the air. Install railfuses. Check for infinite resistance between chassis groundand the transformer cases. If not debug. (you will get a readingbetween DC ground bus bar and these cases, you meter will be charging up thebulk caps)
Connect a ~10K resistor between the output and ground test point on eachbackplane.
Install rail fuses
Bring up on DBT and Variac to 60VAC in on the AC input. Make sure all isgood and no smoke is coming out. Measure that you have B+ and B- voltagespresent at the respective test points and B- at PAD12 and B+ at PAD 11 on eachback plane board.

Check that you have 0V at the output test point.



Take the Variac all the way up and repeat.

Next, before doing anything else, power the amp down and fully DISCHARGE thebulk caps using a 1K 2W resistor (any value close to 1K will do) down to alevel below 1V.

Then you are good to proceed to the next assembly step if this is all good.
Click to expand...
Yeah, thanks. I have that sheet and I've looked it over about 100 times. So I guess it's just time to go get my hands dirty with fingers crossed.
 
scottonnob

scottonnob

Journeyman
#60
Joined
Apr 28, 2015
Messages
251
Tagline
---
#60
Just for clarification, by infinite resistance, I assume you mean just make sure it's an open circuit with the DMM. Also, when you say disconnect the single wire to the left board, I'm assuming you mean the ground that goes to the buss bar. However, I'm a bit confused as to what, specifically, is meant by chassis ground. Where is it? I also don't understand transformer 'cases'. What is meant by cases? I thought my transformer was a single unit without what would be typically specified by 'cases'. Sorry to be such a dim bulb, but I'd rather humble myself and get clarification than muscle through and screw something up.
 
You must log in or register to reply here.
Top