12xxx Dual Voltage Virtual Variac Layout

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LJay942
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12xxx Dual Voltage Virtual Variac Layout

Post by LJay942 » Mon Dec 18, 2017 3:13 pm

Putting together a 12xxx build in the coming weeks using George's transformers and parts from ValveStorm. I have the '67-'68 layout already and a bunch of pictures for reference but I do not have a good diagram for the 3 way standby switch. Can anyone upload a layout or schematic for the dual voltage switching with bias pot? I can't seem to find one that is still hosted either due to Photobucket disabling linking and the great forum crash a few years ago.

Thanks in advance! :vh:

danman
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Re: 12xxx Dual Voltage Virtual Variac Layout

Post by danman » Mon Dec 18, 2017 7:39 pm

I believe that you can find the info on this page which is provided by one of our members. Good luck with the build!https://drive.google.com/drive/folders/ ... jdaSFNBOGM

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LJay942
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Re: 12xxx Dual Voltage Virtual Variac Layout

Post by LJay942 » Mon Dec 18, 2017 11:37 pm

So looking at this, I can just put two legs of a bias pot where the 22k resistor is pictured and ground the pot somewhere on the chassis and am good to go? Any suggestions on grounding location? I will be using a star/Larry ground for this build

Image

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LJay942
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Re: 12xxx Dual Voltage Virtual Variac Layout

Post by LJay942 » Mon Dec 18, 2017 11:41 pm

Also any recommendations for a grounding layout for a 12xxx I have one fora 1969 style build.

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