5e3 question

[bluesaholic]

I just purchased a clark 5e3 chassis...I'm wondering what the ground switch is used for??
And also...should the 12au7 tube be in V1, and the 12ax7 tube be in V2??
Thanks,Terry..

[keysersoze808]

..

I just purchased a clark 5e3 chassis...I'm wondering what the ground switch is used for??
And also...should the 12au7 tube be in V1, and the 12ax7 tube be in V2??
Thanks,Terry..

hi..yeah..v1 12au7,v212ax7.. planing to build from scretch?

[Dougsg38p]

Ground switch

The ground switch was placed on the early Fender amps when the US A/C supply was 2-wires and essentially non-polarized. The switch would change the chassis ground from one A/C lead to the other, to reduce hum.

Sounds dangerous, and it was. I learned to never touch another band mate, or a microphone stand, if my hands were touching the guitar strings.

-de

[TD_Madden]

Put a standby switch in there.

[bluesaholic]

TD...Where do I look for a schematic with a standby switch installed??
Thanks,Terry

[Dougsg38p]

Ground switch

place the switch between pin 8 of the rectifier and the first filter cap.

[bluesaholic]

thanks dougs

[TD_Madden]

of course, my Missions don't have that .047 "deathcap" in there.... :-)

[bluesaholic]

What is the .047 death cap??
Thanks,Terry

[TD_Madden]

C14 on the thumbnail above.

Here's a recent discussion thread regarding this subject:

http://music-electronics-forum.com/s...ighlight=death

[Dougsg38p]

death cap?

the "death cap" referred to is on the primary side of the PT. This was used in the original ground-switch implementations with non-polarized 2-wire suppplies.

C14 in the above clip is on the secondary. It is an open circuit to the B+ dc voltage - it's job is to shunt RF frequencies and transients to ground.

It's optional - feel free to leave it out.

-de

[TD_Madden]

You're right, I misread the schem.