'66 Ampeg 3-wire power cord question

[gui_tarzan]

I'm sure I know the answer to this question but I'm going to ask it anyway. Since the neutral wire from the stock power cord goes into the fuse, then into the switch, then into the PT, and the hot wire goes from the power cord to an eyelet on the board where the second primary PT wire goes, I should be able to put the hot wire on the fuse terminal and the neutral wire on the board eyelet (then the green wire to the chassis) from the new cord, right?

The only reason I'm asking is it looks like the original cord is actually hooked up backwards from the factory. It's no wonder this guy gets zapped no matter what way he plugs into the wall, the 110v is always live!

Everything in this amp looks original and is pristine. It even has a killer sound even though the caps and tubes are all 48 years old. Not a bump, wart, or sign of leakage (physically) on them. I thought at first someone replaced the transformer (gut shots also included) but it's got the right date code.

[Firestorm]

Ditch that .047 cap, too.

[gui_tarzan]

Yes, I was planning on doing that too but why did they put it there to begin with?

[xtian]

Yes, I was planning on doing that too but why did they put it there to begin with?

An anti-hum scheme.

Very pretty amp!

[Jack Hester]

On the pre-'65 models that I have, the hot wire goes to an eyelet on the board. A thermistor jumps across to the opposite eyelet, and out to the PT. I have a '60 model amp that was upgraded in '68 to a '65 circuit board type, and does not have the thermistor. I added one, as I like the soft start that this provides, limiting the inrush current.

Jack

[gui_tarzan]

Yeah, I thought it was odd that it doesn't have a standby switch.

[Phil_S]

In the US, this is how it should be done.
1) Line > fuse > PT
2) Neutral > PT
3) Mains ground > chassis

In the bad old days, they thought something else. It isn't clear what they were thinking. We do know, however, that not every building had + and - wired consistently. I think polarized outlets weren't used consistently in buildings until the 60's.

It seems you know what to do!

[eniam rognab]

In the US, this is how it should be done.
1) Line > fuse > PT
2) Neutral > PT
3) Mains ground > chassis

i agree with you completely phil! may i add something?

1) Line > fuse > switch > PT

i see alot of schematics with the switch on the hot and the fuse on the neutral. fuse should be the first thing 'hot' hits, then switch. modern safety code, although i switch both hot and neutral....

[gui_tarzan]

Agreed, just wanted to double-check.

[Phil_S]

Switch? We don't need no stinkin' switches!