I know this is an old thread, but I thought I would post here, rather than start a new thread, since this does relate to the Valab attentuator. I know this is an upgrade, and I should not expect any assistance, but I am hoping someone that has installed the attentuator may be able to shed some light on its workings. Also, excuse the ignorance, but the Crack was my first ever exposure to an electrical circuit.
I have recently ordered 2, one to be installed in the Crack and the other for my soon-to-arrive Stereomour. Unfortunately, the PCBs are mounted upside down as can be seen in the picture.
(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FmCRRZex.jpg&hash=ab34faa04c285a871acba4bcaff73f1eca41531c)
Thus, I needed to figure out how to connect this to the Crack. After some internet sleuthing and tracing the wire paths, I have determined that my inputs and outputs go to the top and bottom holes while I need to ensure that the left and right channels stay separated. Since resistors have no polarity I am assuming that I can swap inputs and outputs.
However, what throws me off, is the grounding of the attentuator. Based on what I saw on the internet, the grounds are the two center holes. However, there are no conductive tracks from the ground holes to anywhere. Should there not be conductive tracks from the ground hole to something? The stock pot has some conductive tracks on the ground lugs which I assume will be grounded to the chassis itself via the pot. How would grounding work in this case?
I am also attaching a sideways shot of the attentuator.
(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FuBq0zMy.jpg&hash=52c7cfba946667cb442bde4d1ab6ed63cbe9cd77)
The white-and-yellow wire leads to a "solder-spot" marked GND. It only connects to the right side and the left has nothing connecting to it. If I connect my ground wires to the indicated holes in the PCB, they will never reach the solder spot marked GND since the are no conductive tracks. Also, it does not look like this wire will ever connect to the chassis, so what is the point of it? I mean, the top of the wire just ends in a solder joint and I don't think it grounds to anything.
In this case, should I even connect my ground wires to the attentuator itself? Can't I just connect the black wires (1 from the RCAs, 1 from the headphone jack and 1 from T3) directly? Would this not have the exact same effect?
I would be grateful for any input.
Cheers,