Can't tell it better than this Dilbert strip:
This is the top side of the upsampler board (click on the image thumbnails to see them at full resolution):
And this is the underside of the upsampler board, notice the fragile pins than fits into the DIP sockets used by opamps:
Before installing the upsampler, both the output opamps (BB OPA627) and the DAC (TDA 1545) must be removed from their DIP8 sockets
Here is the upsampler board mounted:
This is a side view of the upsampler mounted in the Tjoeb while playing music (notice that the tubes are on)
"Ok, the photos are cool, but does it sound?" Simply put, if you have a Tjoeb CD player, stop reading this and rush buying it! Even a tweaked Tjoeb player, with BB OPA627 opamps and Siemens ECC288, makes a quantum leap in performance with the upsampler, much larger than replacing opamps or tubes.