Reversed electrolytic capacitor?

[folksnake]

Hi All-

First post, have been lurking and learning a while, though. :)

I'm refurbishing an old Univox tube amp, an early 60's model. It may be an early U-72, but it's very hard to tell and they had so many variations and left little information behind for us...

In replacing the caps I have come across two electrolytics whose leads are soldered to the same point. But one cap's lead is positive, and the other cap's lead is negative. The other ends of them end up in different spots on the board (an eyelet, by the way). I'm afraid I can't tell exactly where that shared point leads to/from (mostly because taking the board out would be a major pain). And I don't have a schematic, though I have searched far and wide (again, don't even know the model #).

My question: Is this a mistake, or is there a logical reason to have this arrangement? My research hasn't answered this.

The amp was working beforehand, as I'd said, and the caps seem to be OK (no obvious damage to either one). So I'm guessing it's OK and that I should recap it in the exact same way.

Thanks a lot for any ideas you might have. I've attached a photo with the two suspects marked.

Chris

[jjasilli]

Trace-out where the ground connection is for each cap.  One side of each cap must be going to ground, unless the caps are in series.  If the (+)side of a cap is grounded, it's probably a bias cap for a fixed bias supply. 

[folksnake]

Thank you so much! I am thinking that it must be a part of the bias supply, as you say--thanks for clearing that up for me. Now I can proceed with confidence!

Much appreciated jjasilli!

Chris