It never fails to amaze me what people or "techs" do to equipment!!!

Gepetto

Gepetto

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premiumplus said:
Per Don Imlay's instructions. Online at his site...

One end goes to the copper strap on the filter caps, one goes to the input jack gnd, and the other goes to pin 6 on the driver board.
Don said to cut the original wire going from the input jacks to the driver board, and add a wire from the filters, joining all 3 at input 6 of his board.
Click to expand...
That may not be your problem but that is NOT good advice.
 
premiumplus

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Joe, thanks. It looks like I created a ground loop when I installed the board.
It looks like I misread the instructions.
Don also sent me a cool post about star grounding that I am going to perform when I get the boards from you in the next couple of weeks.
You'll be hearing from my son Jonathan directly...I sent him my wish list and he called yesterday to say that he'll be ordering 2 sets of driver kits, and light boards for a 400 and a 700.
At any rate, I disconnected the ground going from the input jacks to the relay board, and the sine wave smoothed right out.
I'm going to run some more tests then hook it up and see how it sounds.
Thanks guys...this forum is the BEST!

Ok, one last thing...it's official THREAD CRAPPING TIME!!!
I did see that 400 on eBay with the fuse holders drilled into the front panel too...hilarious. I even saw one with a butt ugly power switch too...
 
Gepetto

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premiumplus said:
Joe, thanks. It looks like I created a ground loop when I installed the board.
It looks like I misread the instructions.
Don also sent me a cool post about star grounding that I am going to perform when I get the boards from you in the next couple of weeks.
You'll be hearing from my son Jonathan directly...I sent him my wish list and he called yesterday to say that he'll be ordering 2 sets of driver kits, and light boards for a 400 and a 700.
At any rate, I disconnected the ground going from the input jacks to the relay board, and the sine wave smoothed right out.
I'm going to run some more tests then hook it up and see how it sounds.
Thanks guys...this forum is the BEST!

Ok, one last thing...it's official THREAD CRAPPING TIME!!!
I did see that 400 on eBay with the fuse holders drilled into the front panel too...hilarious. I even saw one with a butt ugly power switch too...
Click to expand...
hi Dave
i have a complete preferred ground schematic for the PL700 posted in The PLWO archives section of this site. It should be followed religiously for maximum performance. The original PL grounding scheme was flawed.
 
Gepetto

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premiumplus said:
Joe, thanks. It looks like I created a ground loop when I installed the board.
It looks like I misread the instructions.
Don also sent me a cool post about star grounding that I am going to perform when I get the boards from you in the next couple of weeks.
You'll be hearing from my son Jonathan directly...I sent him my wish list and he called yesterday to say that he'll be ordering 2 sets of driver kits, and light boards for a 400 and a 700.
At any rate, I disconnected the ground going from the input jacks to the relay board, and the sine wave smoothed right out.
I'm going to run some more tests then hook it up and see how it sounds.
Thanks guys...this forum is the BEST!

Ok, one last thing...it's official THREAD CRAPPING TIME!!!
I did see that 400 on eBay with the fuse holders drilled into the front panel too...hilarious. I even saw one with a butt ugly power switch too...
Click to expand...
Hi Dave
hoping you only have ONE wire going to that ground node on the DC protect board now. That wire should go directly from that node to the star ground. Likewise board pin 5 should go to the star ground
 
premiumplus

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All right, guys!
The 700B is back in service and sounds good.
Next step...Christmas morning I unwrap some WOPL goodness and install boards in it and one of my 400's.
Thanks for helping and encouraging. It's nice not to be alone at that bench, isn't it?
Dave
 
laatsch55

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Dave, please acknowledge that you read Joe's posts about the ground scheme or we'll keep hounding you about it. It's critical that the ground scheme is followed exactly as Joe depicts it. His version needs to be grounded as per his suggestions.........
 
wattsabundant

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laatsch55 said:
Dave, please acknowledge that you read Joe's posts about the ground scheme or we'll keep hounding you about it. It's critical that the ground scheme is followed exactly as Joe depicts it. His version needs to be grounded as per his suggestions.........
Click to expand...
The info I sent Dave was Joe's post. I did not intend to insinuate it was my own. I'll be more careful to give proper credit in the future.

When testing the amps on the bench it's absolutely critical that no ground loops be inserted with the test equipment. Doing so causes will oscillations.

In reference to front panel fuses, I used to do mods to 400's for pro applications with 5 fuses and a power switch on the front panel. The one on EBAY is a cluster#$%^&. Series II amps had the panel milled and fuses mounted on the sub panel. They looked really sweet.
 
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laatsch55

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Don , the absence of credit was as far from my mind as the setting sun. It make no difference where it comes from as long as it gets to em. Besides, we're not like that around here, you know that.

BTW, nice resistor on the Zoebel now!
 
premiumplus

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laatsch55 said:
Dave, please acknowledge that you read Joe's posts about the ground scheme or we'll keep hounding you about it. It's critical that the ground scheme is followed exactly as Joe depicts it. His version needs to be grounded as per his suggestions.........
Click to expand...
Yeah, sorry...our posts were crossing in the mail, so to speak.
I got Joe's info and exchanged PM's with him too. The amp is fully operational and quiet as can be. The ground loop was created by an extra wire going from the protect board over to the input jack ground.
Thanks again, all.

I'm going to go through the amp and completely redo the grounds per Joe's instructions when I get the parts from White Oak.

An aside to all: I'm grateful for the SPIRIT of this place. Phoenix is unique in not letting personalities get in the way of the message and I'm happy (proud) to be a small part of it. Love it here! Thanks again.

Dave
 
laatsch55

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Got a guilty conscience there Av?? Good to see ya post Avionic!! (he's also a Dave, Dave)
 
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