Crack is my fourth Bottlehead build and completes my set of headphone amps. In order I built the S.E.X. (standard with C4S), Mainline (with some big caps), Crackatwoa (with a few cosmetic mods) then Crack, a somewhat random journey.
With this build I wanted to continue the theme I started with the Crackatwoa.
https://forum.bottlehead.com/index.php?topic=14324.0My goal was to have zero visible fasteners. Crack has few fasteners to begin with, but swapping in the 4PIN XLR and recessed RCAs adds another 6.
Thanks to a suggestion from forum member Karl5150 I opted for stud inserts to eliminate the through holes. The plate/studs were obtained from Front Panel Express.
I've just test fit the hardware for these photos and will complete the wiring soon. Don't worry Doc, I'll build it standard first then add the Speedball!
Some tips/notes on the studs:
- Do not have them installed by the manufacturer. Have the locations machined and the studs supplied uninstalled. The manufacturer uses epoxy in addition to the threads. The epoxy creates significant resistance to ground and the studs will not serve as good ground points. Install the studs yourself without glue, using threadlocker if you wish, and you will achieve less than 1 ohm resistance to ground. My plate has about 1/2 ohm resistance between any two studs. My plate is powdercoated. The manufacturer machined all elements of the design, except the stud placement, then powdercoated, then machined the stud locations, leaving a nice path to ground for each stud.
- I specified load bearing studs in all locations. These are rated to support a load, such as a transformer. Using these means your plate will need to be a minimum of 3mm thick. Non load bearing studs are also available and these have a smaller footprint and lesser requirement regarding plate thickness.
- Load bearing studs require more space between them and the nearest edge of the plate or nearest through hole. With the benefit of hindsight I could have used load studs for the tube sockets (firm pressure is often required to seat the tubes) and regular studs for everywhere else.