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jbever
01-06-2008, 11:44 PM
I picked up a champ type build an had a few questions about mods by previous owner.

1. On the left hand side of the picture, there's a 510 ohm cement resistor that is wired to the OT and then looks like is grounded to chassis. Purpose?

2. There's a .0047 cap that is jumped from pin 3 on the power tube to pin 8 of the rectifier. Purpose?

3. Hard to see but at the pilot light there's a term strip with a resistor. Is this just because the person didn't have a regular pilot light to stick in?

Thanks in advance for your help.
Jerry

Picture link:
http://picasaweb.google.com/FrannieAK/JbeverPhotos/photo#5152486600588403074

Dave Curtis, dB AudioTech
01-07-2008, 12:19 AM
I picked up a champ type build an had a few questions about mods by previous owner.

1. On the left hand side of the picture, there's a 510 ohm cement resistor that is wired to the OT and then looks like is grounded to chassis. Purpose?

To lower B+ voltage.

2. There's a .0047 cap that is jumped from pin 3 on the power tube to pin 8 of the rectifier. Purpose?

Snubber cap. Maybe it was squeeling.

3. Hard to see but at the pilot light there's a term strip with a resistor. Is this just because the person didn't have a regular pilot light to stick in?

Dropping resistor for the neon.

Thanks in advance for your help.
Jerry

Picture link:
http://picasaweb.google.com/FrannieAK/JbeverPhotos/photo#5152486600588403074

No problem. From a glance, this amp has solder-related issues you might want to address, but you might want to rewire the AC first. The white neutral from the cord should go directly to one side of the power transformer primary, and the black from the cord should go through the fuse and then the switch to the other side of the primary. Whoever built it switched the neutral, and that's a no-no nowadays.

jbever
01-07-2008, 02:26 AM
Thanks Dave,
I plan on ordering a new chassis and board and rewiring it stock. I just wanted to know what they did before I dug into it.
Jerry