Engineering question about standby switches

9/27/2000 9:54 PM

nuke

Engineering question about standby switches On the subject of standby switches in tube amps with SS rectifiers:     Many, maybe most, amps that have SS rectifiers have one set of filter caps right at the rectifier, followed by the switch to the plate supply of the output section.     rectifier->caps->switch->B+     I prefer a different arrangment for various reasons:     rectifier->switch->caps->B+     The main reason is this avoids the "bump" when cutting the current on. It also helps keep the voltages on the first filters from getting out of hand, since sometimes the combination of high mains voltage and the naturally increased voltage present on an unloaded transformer.     However, my question is whether there's any reason to not use my preferred arrangement?     I can't think of any, except the switch will take the brunt of the initial current surge into the uncharged filters. That might compromise the long-term reliability of the switch. Given the fairly robust nature of the usual carling switches, I don't think it is a big issue, particularly with roughly 40uf or so of bulk capacity in the filters.     What do you guys think?