700 B WOPL New build Question

[Gepetto]

Can someone clarify the grounding scheme when using the full WOPL upgrades and the watts DC protect board on the 700B ?

1) RCA input , just shielded cable to the copper ground plane NO case ground ... Yes ?

2) A single ground from pin 6 of the protect board to the star point ground .... Yes ?

The Watts abundant instructions call for multiple grounds.... Notes at the end of the White Oaks instructions say different.....

What is the proper configuration ???

Mattoe

Yes and Yes, but you need to add 2 18AWG ground runs from the star point ground to appropriate pins of the J1 and J2 terminal blocks on the DCP as well.

 

[mattoe]

Thanks for the reply !

Are you thinking of the 400 ? The 700 board has one Phoenix connector with 7 connections.. This is what I think the connections should be

1 Left channel
2 Left channel gnd
3 Right channel
4 Right channel gnd
5 AC from rectifier
6 New wire to star gnd ?
7 AC from rectifier

The confusion is if any other gnd is required at pin 6 ....

Mattoe

 

[jbeckva]

Can someone clarify the grounding scheme when using the full WOPL upgrades and the watts DC protect board on the 700B ?

1) RCA input , just shielded cable to the copper ground plane NO case ground ... Yes ?

Correct, grounds tied together, then soldered onto shield. Shield floats above the chassis with the swedge washers.

2) A single ground from pin 6 of the protect board to the star point ground .... Yes ?

Correct

 

[jbeckva]

Thanks for the reply !

Are you thinking of the 400 ? The 700 board has one Phoenix connector with 7 connections.. This is what I think the connections should be

1 Left channel
2 Left channel gnd
3 Right channel
4 Right channel gnd
5 AC from rectifier
6 New wire to star gnd ?
7 AC from rectifier

The confusion is if any other gnd is required at pin 6 ....

Mattoe

Single ground, but use it twisted pair style with the 2 acs, and route on the top. Other GNDS and +/- DC on the bottom.

 

[mattoe]

Sounds good ! Thanks.... I just realized something... My 700B Has a 3 prong AC cord.... Looks to me like a addition sometime in its past.... The wire relief through the chassis just doesn't look right... The ground wire is bolted to the chassis just as it enters...... I assume the 700 B never had a grounded plug ? Your thoughts ??? Ground or not to ground ?

Mattoe

 

[WOPL Sniffer]

Not to ground........... I TRIED IT AND NO WORKY WORKY.... I even tried grounding through the unused DC/Normal switch, so you could switch the ground on and off, no effect (affect) (oh, i'm infected)....

 

[mattoe]

Did you end up with noise ? Or , just no effect at all ?? I don't know what the idea was .... Shock protection maybe ?

Mattoe

 

[WOPL Sniffer]

Did you end up with noise ? Or , just no effect at all ?? I don't know what the idea was .... Shock protection maybe ?

Mattoe

It didn't affect the WOPL at all. Maybe if I was sitting in the bathtub with a WOPL on my lap............ Joe or Lee may be able to elaborate but with Joe's New chassis kits, we don't wire in the ground.

 

[jbeckva]

Ground loop... no 3rd ground wire for WOPL's (nor stock amps for that matter).

 

[laatsch55]

What he said......

 

[mattoe]

100v bias reading Help !

Hey Guys,

I was up late getting the final assembly complete but I have a problem ! I ran the 700 up with the variac and DBT without the driver board and all outputs installed all was well.....
"Click" from the protection board... Wired in the driver board ... No click ? I found 100v output from the left back plane board to the protect board... 100 V at the left bias test point!
The right bias test point is steady at .350 mv and has a wide range if I tinker with the pot..... No smoke ... panel lights are good.... Point me in the right direction ?

Thanks !

Mattoe

 

[WOPL Sniffer]

Check your bias transistor. Too much heat when you solder them in will kill them. I use a heat sink (a little Joe) across the leads when soldering.

 

[mattoe]

Help ???

I pulled the Bias transistors and switched them left to right No change ...... .Ideas ? I thought I was gonna have this 700B booming tonight ......

Mattoe

 

[Gepetto]

Hey Guys,

I was up late getting the final assembly complete but I have a problem ! I ran the 700 up with the variac and DBT without the driver board and all outputs installed all was well.....
"Click" from the protection board... Wired in the driver board ... No click ? I found 100v output from the left back plane board to the protect board... 100 V at the left bias test point!
The right bias test point is steady at .350 mv and has a wide range if I tinker with the pot..... No smoke ... panel lights are good.... Point me in the right direction ?

Thanks !

Mattoe

Hi Matt
Assuming your voltage on the left channel is PLUS 100V. You did not give a sign, only the magnitude.

First thing to check is that you have ~-100 on pad 12L of the left channel on the control board and ~+100 on pad 11L of the left channel on the control board. You may not have the -100 connection from the backplane to the control board on pad 12L. Each channel is independent.

Check that out and report back.

 

[WOPL Sniffer]

I pulled the Bias transistors and switched them left to right No change ...... .Ideas ? I thought I was gonna have this 700B booming tonight ......

Mattoe

Yer asking for trouble, don't swap delicate components, use a meter and CHECK them.

 

[mattoe]

Thanks for your response ! I truly appreciate the help ! So, yes pad 12L -103v pad 11L +103v Have you got a next step in mind ?

Mattoe...

 

[laatsch55]

What are you measuring for DC on the speaker posts?

 

[laatsch55]

Excuse me, between ground and output on the testpoints on the afflicted channel?

 

[mattoe]

I have +101v out of the left backplane to the DPB and 0v out from the right..... Right channel looks good with a .350v bias ..... I assume the output relay will not close because of the +100v

Mattoe...

 

[laatsch55]

That's correct, and every thing was fine till you soldered in the driver board??