Suitable Shoulder Washer & Flat Washer

[ZeusMC]

Hi Guys

Keystone offers two nearly identical fiber washers, the only difference being the overall diameter of 0.75" or 0.625". They are the 3241 and 3069, respectively. Both are like the Switchcraft part in that the shoulder is only 0.032" high and the washer is 0.063" thick.

Where the open-frame Switchcraft jacks can provide a very long service life, they do have their flaws. The main one is the fact the entire "sandwich" of the jack contacts and insulators is held together by a single crimp. This crimp has to resist the twisting forces of tightening the jack and nut during installation, and remain tight over the life of the jack with countless insertions and extractions of the plug end.

Unless the chassis is very thin, you have to use the long-bushing versions of the jack to have space for the insulating washers. On my older amps I used plastic dress panels, so one side was taken care of., then a shoulder washer inside. The chassis, dress panel and washer ate up 3/16" of the available thread, and adding a toothed washer another 1/16". I use plastic jacks since switching to PCB-mounted types. I have also just switched to metal dress panels.

If you need an insulated jack, it is best to use a plastic jack with a burly threaded section, such as from Neutrik or Re'an. The Switchcraft plastic jacks use a brittle-seeming thin plastic and the contacts are smaller than on the other brands.

Ok, cheers Kevin.