I made new
THE PRO BOX adapter. I bought made in Canada electric box for it. I took some photos how to make such a thing. This box could be opened afterwards since it is assembled together with 4 screws.
Here are the most of things you need to make it. 1mm (18gauge) thick copperwire for the pins is covered with lacquer, so it need to be removed first by grinding.
Here are the parts for the pins. B7G socket is just to keep pins more straight when gel super glueing pins through pin protector/straightener. I grind wire head more round.
Here it is waiting drying.
I made holes to bottom of the box. Paper is there protecting little dot from getting any epoxy. You just push pins through paper. I glued parts together with epoxy.
This show the extra wires for the switch.
And how the switch is connected to the B9A socket.
Soldered all rest wires. Cutted those additional copper wires shorter after taking photo.
And here is ready to use product.
Sharp-eyed can see that i connected heating from both channels. I measured that they are connected anyway inside little dot. So i think with double wiring i can use up to 0.9A heater current.
First wooden box with crappy tube bottoms had very little humming in the right channel with ecc83 tube. It was so little that needed completely silence to notice. Now all humming is gone. I think that there is no need for any kind grounding to pin9 for 6V tubes. Stereo imaging and channel separation is excellent for my hearing.
Enjoy!
Edit: Box type is 1591MSBK from hammond manufacturing.