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 Post subject: 1975 Silverface Champ upgrades
PostPosted: Sat Feb 16, 2013 7:27 pm 
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I was looking for some advice on upgrade, I got a new power tube but Im looking for a new rectifier and preamp tube also a speaker. Any thoughts? Also what is the "death cap" ? Do silverface champs from '75 have this? Is it a problem? & is a 2 prong cord better than a 3 prong cord?


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 Post subject: Re: 1975 Silverface Champ upgrades
PostPosted: Sat Feb 16, 2013 7:33 pm 
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Yes, the Silverface Champ has a death cap.

Yes, you want to get rid of it.

Yes, you want to replace the two prong power cord with a three prong grounded cord.

Do all this before anything else to avoid the possibility of electrocution.

Some nice NOS tubes can be found here:

https://www.kcanostubes.com/

No speaker recommendations. Sorry.

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 Post subject: Re: 1975 Silverface Champ upgrades
PostPosted: Sat Feb 16, 2013 8:12 pm 
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bluesky636 wrote:
Yes, the Silverface Champ has a death cap.

Yes, you want to get rid of it.

Yes, you want to replace the two prong power cord with a three prong grounded cord.

Do all this before anything else to avoid the possibility of electrocution.

Some nice NOS tubes can be found here:

https://www.kcanostubes.com/

No speaker recommendations. Sorry.


Thanks, where is the death cap and do you get rid of it?


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 Post subject: Re: 1975 Silverface Champ upgrades
PostPosted: Sat Feb 16, 2013 8:25 pm 
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Attached to the fuse. Just unsolder or cut it off.

http://ampwares.com/schematics/champ_aa764.pdf

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 Post subject: Re: 1975 Silverface Champ upgrades
PostPosted: Sat Feb 16, 2013 8:57 pm 
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bluesky636 wrote:
Attached to the fuse. Just unsolder or cut it off.

http://ampwares.com/schematics/champ_aa764.pdf


Ok I found it, My amp came with a 3 prong power cord but the 3rd prong was taken out so I just replaced the plug part. What is the purpose of the death cap if it was in 2 prong corded amps and mine was 3 prong?


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 Post subject: Re: 1975 Silverface Champ upgrades
PostPosted: Sat Feb 16, 2013 11:01 pm 
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 Post subject: Re: 1975 Silverface Champ upgrades
PostPosted: Sat Feb 16, 2013 11:04 pm 
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Bedlam9 wrote:
bluesky636 wrote:
Attached to the fuse. Just unsolder or cut it off.

http://ampwares.com/schematics/champ_aa764.pdf


Ok I found it, My amp came with a 3 prong power cord but the 3rd prong was taken out so I just replaced the plug part. What is the purpose of the death cap if it was in 2 prong corded amps and mine was 3 prong?


Ummm, did you make sure that the ground (3rd) wire of the power cable is actually grounded to the chassis?

The cap provided a ground for the power cable on the primary side of the power transformer. However, depending on the orientation of the power plug in the power outlet, the chassis could be at ground potential or it could be hot. If the chassis was hot and you touched the chassis (through the guitar strings which are grounded to the amp) and another piece of equipment, such as a microphone, you could receive a potentially fatal shock. :shock:

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 Post subject: Re: 1975 Silverface Champ upgrades
PostPosted: Sat Feb 16, 2013 11:05 pm 
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Powdered Toast Man wrote:
Speaker: Weber 8A125


4 ohms.

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 Post subject: Re: 1975 Silverface Champ upgrades
PostPosted: Sat Feb 16, 2013 11:19 pm 
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bluesky636 wrote:
Bedlam9 wrote:
bluesky636 wrote:
Attached to the fuse. Just unsolder or cut it off.

http://ampwares.com/schematics/champ_aa764.pdf


Ok I found it, My amp came with a 3 prong power cord but the 3rd prong was taken out so I just replaced the plug part. What is the purpose of the death cap if it was in 2 prong corded amps and mine was 3 prong?


Ummm, did you make sure that the ground (3rd) wire of the power cable is actually grounded to the chassis?

The cap provided a ground for the power cable on the primary side of the power transformer. However, depending on the orientation of the power plug in the power outlet, the chassis could be at ground potential or it could be hot. If the chassis was hot and you touched the chassis (through the guitar strings which are grounded to the amp) and another piece of equipment, such as a microphone, you could receive a potentially fatal shock. :shock:


I'll look into the weber, as for the death cap, I removed it, here's a picture of the chasis(before death cap removal)http://i.ebayimg.com/t/VINTAGE-FENDER-SIVERFACE-CHAMP-1975-/00/s/NDgwWDY0MA==/$(KGrHqF,!rMFDILqhLbPBR!ZltM9zw~~60_3.JPG Am I good to go now that I removed the death cap?


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 Post subject: Re: 1975 Silverface Champ upgrades
PostPosted: Sat Feb 16, 2013 11:31 pm 
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Bedlam9 wrote:
I'll look into the weber, as for the death cap, I removed it, here's a picture of the chasis(before death cap removal)http://i.ebayimg.com/t/VINTAGE-FENDER-SIVERFACE-CHAMP-1975-/00/s/NDgwWDY0MA==/$(KGrHqF,!rMFDILqhLbPBR!ZltM9zw~~60_3.JPG Am I good to go now that I removed the death cap?


One ... more ... time. Did you make sure that the ground pin of the power plug is actually connected to chassis ground? I can't tell from the photo.

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 Post subject: Re: 1975 Silverface Champ upgrades
PostPosted: Sun Feb 17, 2013 12:06 am 
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bluesky636 wrote:
Bedlam9 wrote:
I'll look into the weber, as for the death cap, I removed it, here's a picture of the chasis(before death cap removal)http://i.ebayimg.com/t/VINTAGE-FENDER-SIVERFACE-CHAMP-1975-/00/s/NDgwWDY0MA==/$(KGrHqF,!rMFDILqhLbPBR!ZltM9zw~~60_3.JPG Am I good to go now that I removed the death cap?


One ... more ... time. Did you make sure that the ground pin of the power plug is actually connected to chassis ground? I can't tell from the photo.


The power cord has 3 wires, black, white, and green. the green wire is soldered to the chassis.


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 Post subject: Re: 1975 Silverface Champ upgrades
PostPosted: Sun Feb 17, 2013 12:42 am 
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If the amp has the original cap can or some jerry-rigged individual cap setup --- I'd go for something like this. Don't let the can or aftermarket caps leak out on the circuit. Esp if you plan on playing the amp at "10," Which nearly everyone does, with one of these amps.

Good luck with it!


http://www.tubesandmore.com/products/C-EC20X3-525


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 Post subject: Re: 1975 Silverface Champ upgrades
PostPosted: Sun Feb 17, 2013 12:58 am 
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I just don't get why an amp with an original three prong was made with a death cap.


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 Post subject: Re: 1975 Silverface Champ upgrades
PostPosted: Sun Feb 17, 2013 1:03 am 
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Bedlam9 wrote:
I just don't get why an amp with a three prong has a death cap.


The larger -- more powerful -- mid-70's silverface amps had a 3-conductor power cord AND the customary rear-panel ground (polarity) switch.

Go figure!

:lol:

Arjay

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 Post subject: Re: 1975 Silverface Champ upgrades
PostPosted: Sun Feb 17, 2013 1:53 am 
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Bedlam9 wrote:
bluesky636 wrote:
Bedlam9 wrote:
I'll look into the weber, as for the death cap, I removed it, here's a picture of the chasis(before death cap removal)http://i.ebayimg.com/t/VINTAGE-FENDER-SIVERFACE-CHAMP-1975-/00/s/NDgwWDY0MA==/$(KGrHqF,!rMFDILqhLbPBR!ZltM9zw~~60_3.JPG Am I good to go now that I removed the death cap?


One ... more ... time. Did you make sure that the ground pin of the power plug is actually connected to chassis ground? I can't tell from the photo.


The power cord has 3 wires, black, white, and green. the green wire is soldered to the chassis.


And you have measured continuity from that chassis solder joint to the ground pin of the plug using an ohm meter? I don't care what wires you see. I want to know what you measured. Its a "yes" or "no" answer.

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