Well here it is - an assembled v2.2 Stepped Attenuator. The assembly went fairly smoothly; actually very smoothly compared to previous versions. Some of the improvements I made where aimed at improving the ease of assembly. I started the electrical testing and have run into a few minor snags like finding out that I installed the ladder resistors in the wrong order. Oops. This is nothing that a little careful desoldering/resoldering can’t fix. I also have a problem with the length of the flex cables that are part of the resilient mount design for the relay ladder. The flex cables are too long pinning the relay ladder against the top of the vacuum chamber. I have ordered shorter flex cables which should arrive in a couple of days. I may also try an even smaller pitch version of the flex cables if the shorter cables are too rigid but this requires updating three of the printed circuit boards (again!).

Within a week or so I should have all the electrical testing complete and the minor problems sorted out. At that point I will evacuate the vacuum chamber and have completed the v2.2 attenuator. Actually two v2.2 attenuators for a stereo pair.

Next, I have updated the remote design (I already have the parts for this) and have plans to update the phono pre-amp to get some more gain. Oh ya, I also have also all the parts for a pair of “headless” v2.2 attenuators used in the passive pre-amp design. Lots to do…