Ampeg V2 - a few quick questions

[yaryaryar]

Hi all,

I have a few quick questions regarding an early 70s Ampeg V2 that I'm working on. The schematic and a couple photos are attached.

1. Is it possible that I have two death caps? I installed a 3-prong cord, and I'd like to get rid of these guys, but just want to double check. See the attached photo - it looks like there's actually two .047uf caps in series with one end going to ground, and the other going to the polarity switch. It seems strange that I have two in there... is there any reason to keep them?

2. One of my bias supply caps has been replaced. The schematic calls for both C15 and C23 to be 10/100. C23 looks to be original, but C15 was replaced with a 50uf/100v cap. Is that ok? My gut is telling me I should go ahead and replace both and make them 10/100s.

3. If I want to do a trimpot for adjusting bias, I've read elsewhere that I should replace the 75k resistor at R49 with a 56k resistor and 20k pot. Does that check out?


Thanks so much for the help.

[52 Bill]

Is it possible that I have two death caps? I installed a 3-prong cord, and I'd like to get rid of these guys, but just want to double check. See the attached photo - it looks like there's actually two .047uf caps in series with one end going to ground, and the other going to the polarity switch. It seems strange that I have two in there... is there any reason to keep them?

I haven't seen that before, but I guess it is possible to have two caps in series, maybe to raise the voltage rating. If you have installed a 3-wire cord, just cut them both out.

One of my bias supply caps has been replaced. The schematic calls for both C15 and C23 to be 10/100. C23 looks to be original, but C15 was replaced with a 50uf/100v cap. Is that ok? My gut is telling me I should go ahead and replace both and make them 10/100s.

The higher rated cap is fine, but it doesn't fit very well. If you want just get two new 10uF or 22uF caps and make it nice.

If I want to do a trimpot for adjusting bias, I've read elsewhere that I should replace the 75k resistor at R49 with a 56k resistor and 20k pot. Does that check out?

Yes, that mod should work fine.