Invisible 220K 1W resistors on SUper reverb caps

[Underwood]

   I am doing the caps on a SUper reverb and I see 220K 1W resistors on the 70uf 350V caps on the schematic. Under the doghouse is a 4.7 and 1K for the 20uf 500V caps, but no 220K 1W on the 70uf. I also could not find any 70uf, so I got 80uf. I think that is all sprague makes now. Any help would be appreciated.  THANKS!!!!!

[HotBluePlates]

Did you unsolder the existing caps? Normally those resistors are tight against the board, while the body of the caps obscure them from view.

[Underwood]

 No I haven't. They are under the board? I never knew that. I probably left some old crusty resistors on some of my other amps then. I usually just clip and solder when I put new caps on. I never took the board off. Is that wrong?  THANKS!

[HotBluePlates]

No, not under the board.

The caps are big cylinders, right? Lay 2 beer cans on their side on your kitchen counter. Peep at the ends of the cans. See some daylight between where the cans touch and the counter's surface?

That's where the 220kΩ's usually hide. On the top-side of the board, but under the caps.

[Willabe]

No not under the board, under/along side of the 2 caps.

That is only on the Fender amps that have the 2x70uFx350v caps which are in series. The R's are for forced voltage sharing on the 2 caps so 1 cap doesn't carry more than the other and go over it's 350v limit. Fender amps that have 2x40uFx500 (525) v caps don't have the R's because their in parallel and don't need the forced voltage sharing.  

The R's also bleed off the B+ dcv when you turn off the amp.


             Brad    

[Underwood]

I see 'em!  I guess I could've waited 'til I actually unsoldered the caps before I psted this ? THanks!! The 80uf 450V OK to use, correct?

[Willabe]

Yes if it fits, might be a little long? Don't let the end connections, well the B+ end short to the cap can cover.

I'm sure Sprague still makes the 70uFx350v cap, next time try Mouser or use 2x20uFx500v caps from our host Doug's on line store.


             Brad    

[stratele52]

Underwood ,

You may use the worng schematic ,

SR schematic AA 763 do not have those resistor and SR schematic AA270 have them

[sluckey]

You may use the worng schematic

You did read that he found the resistors, right?

[stratele52]

You may use the worng schematic

You did read that he found the resistors, right?

No I have not see his answer , Thank's ;

,"    I see 'em!   I guess I could've waited 'til I actually unsoldered the caps before I psted this ?   THanks!! The 80uf 450V OK to use, correct?  "