dynaco st-70 can capacitor replacement questions

[paysonmark]

OK, I am re-capping my st70 and I bought a 80/40/30/20 525v can cap from AES in AZ.
I have read that the 80uf lug needs to face the back of the chassis.
I am not sure of the orientation of the symbols on the bottom.
Do I install the same as the factory 30/20/20/20 or do I turn 90 degrees counter clockwise

80 is D
40 is square
30 is triangle
20 blank

 

[paysonmark]

Thank you for responding, Im new to the tube game.... does that mean turn the can 90 degrees clockwise or ccw, and wire it per the wire diagram. I just want to be accurate and not destroy anything thx

 

[triode17]

OK, I am re-capping my st70 and I bought a 80/40/30/20 525v can cap from AES in AZ.
I have read that the 80uf lug needs to face the back of the chassis.
I am not sure of the orientation of the symbols on the bottom.
Do I install the same as the factory 30/20/20/20 or do I turn 90 degrees counter clockwise

80 is D
40 is square
30 is triangle
20 blank

BTW, the mark next to 80 is not D, it's a half-moon.

 

[billyz]

The aes can cap is marked as to which section is what. The 40uf should be the first cap after the rectifier. That is pin 8 of the rectifier and circle 2 on the schematic. The 80uf section goes after the choke circle 1, where the 20uf section was. I would attach the 30uf section next to circle 4 and the the 20uf to circle 3. Rotate the can however you need , to fit and wire. And make sure it is grounded to the chassis at the original point as found on the chassis.

 

[triode17]

Why 30µF on "circle 4" vs. "circle 3?" Are you saying the phase splitter would benefit more from the extra 10µF than the pentode amplifier section would?

Probably, its doing more work than the pentode.
Here's side note for your rebuild. Be sure to connect the 15.6Ohm current sensing resistors to the main capacitor ground. Dynaco was using the tube sockets frame mounted on the chassis as its ground. I had one like this, and I chased around an unstable bias current in one channel for hours, until I measured a few ohms from the 15.6 Ohm ground lead to the main cap.

 

[paysonmark]

GOT IT, great help all, thank you

 

[nj pheonix]

Here's side note for your rebuild. Be sure to connect the 15.6Ohm current sensing resistors to the main capacitor ground. Dynaco was using the tube sockets frame mounted on the chassis as its ground. I had one like this, and I chased around an unstable bias current in one channel for hours, until I measured a few ohms from the 15.6 Ohm ground lead to the main cap

Thanks
I did one a while back to the manual layout without issue.
Anything to make it more reliable in the future is a plus.
If I do another I'll have to keep that in mind.

 

[paysonmark]

all is working, sweet sounds
thx all