12xxx Larry Ground

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Coned1969
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Re: 12xxx Larry Ground

Post by Coned1969 » Sat Sep 28, 2013 11:16 pm

vh junkie wrote:Image
Sorry for the newb question...I'm trying to figure out what the long black wire hanging off of ground point #1 is connected to. It kind of gets lost in the photo. Could someone please fill me in?

Thx

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Re: 12xxx Larry Ground

Post by gloeidraad » Sun Sep 29, 2013 3:39 am

Thats the centertap from the heaterwinding.

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vanhalen5150
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Re: 12xxx Larry Ground

Post by vanhalen5150 » Sun Sep 29, 2013 6:21 am

Yeah. It's usually located between your 2 heater wires coming off the PT.
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Coned1969
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Re: 12xxx Larry Ground

Post by Coned1969 » Sun Sep 29, 2013 10:01 am

Got it...the yellow/green wire on my PT. I have that connected to the PI cap ground lug at present. Is it worth moving it to ground point #1 or would it be OK to leave it where it is?

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neikeel
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Re: 12xxx Larry Ground

Post by neikeel » Sun Sep 29, 2013 10:14 am

Coned1969 wrote:Got it...the yellow/green wire on my PT. I have that connected to the PI cap ground lug at present. Is it worth moving it to ground point #1 or would it be OK to leave it where it is?
Yes - definitely :wink:
Neil

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Re: 12xxx Larry Ground

Post by Coned1969 » Sat Oct 05, 2013 5:44 pm

I have two more grounding questions:

1) In this photo...what does the black "Bias Ground" wire connect to (which grounding point AND which component on the other end)?
vh junkie wrote:Image
2) In the "old school" grounding scheme, the input jacks would get grounded to the buss wire on the back of the tone pots. Where do the input jacks get grounded in Larry's scheme? I didn't see anything in the photos.

Thanks!

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Re: 12xxx Larry Ground

Post by vh junkie » Sat Oct 05, 2013 10:28 pm

When looking at this thread , it is useful to refer to the first post:
Cobbled from first post:
#1 - Heater common, Inputs and V1 Cathode
#2 - Volume controls and V2 Cathode
#3 - PI filter ground ,Tone stack, presence grounds, and speaker ground
#4 - Bias ground, Screens filter ground
#5 - Mains filter ground.
1) In this photo...what does the black "Bias Ground" wire connect to (which grounding point AND which component on the other end)?
The bias ground goes to #4. The other side is the positive side of the bias caps.
2) In the "old school" grounding scheme, the input jacks would get grounded to the buss wire on the back of the tone pots. Where do the input jacks get grounded in Larry's scheme? I didn't see anything in the photos.
Inputs are grounded at #1
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Re: 12xxx Larry Ground

Post by Coned1969 » Sun Oct 06, 2013 11:33 am

Thanks...makes perfect sense now!

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