in the russian build I think he is talking about this one also. You would use both, one reason is the rca plug fits the 510 connector and it screws into the long 1/4" jack tube so you could mount the ego
tank inside.
Here is a link, I tested it for workability
RadioShack
I am getting one like that tomorrow and I'll see, but I think I am right.
I already have the 1/4" phono jack and a rca plug does not screw into it.
Something the russian lecturer commented on "chinese standards" being what they are..
The important thing is the jack has to unscrew, some are sold like that but do not unscrew..