Where to put Standby switch?

[Q delorenzis]

I have converted a Hammond L100 organ amp from a ruined organ, into a guitar amp. So far I've added a power switch, 1/4 inch jack, gain knob and standby switch BUT my question is,

Where should I be putting the standby switch? Right now I just have a 2 way switch giving the speaker load to a 25W 8 ohm resistor but I don't think that's right. I have seen some builds that place the standby switch just before the first filter cap. Is that the right place for it? Also how can I add tome tome and volume pots? Thanks

[JoeM]

MerlinB has a good article on the standby switch:

The Valve Wizard

[Enzo]

You don;t need a standby switch. But you can plpace it all over the place. Before the rectifier, after the rectifier, after the place and before the screen. And that is just the B+ spots. The thing can also lift cathodes of power tubes, or short opposing power tube grids together, in fact anything that removes signal from the powr tubes will do it.

The ONLY purpose for the switch is to silence the amp.

[mac1amps]

Well, to each his own. I've always encouraged the use of S.B. switches, primarily to give the power (and rectifier, when present) a "rest" from high voltage, while retaining the "warmed-up" mode during a break, etc. Especially good for amps that operate very hot (like older A.C. 30's that don't have one, or Orange amps that never had them). I'll confess that they're also handy to have when you're servicing the amps as well.....'not trying to dis-respect Enzo's opinion (I know everyone [including myself] praises his "say" on things here)....'just giving my perspective.

[Enzo]

Please, disagree all you like. I am always interested in views differing from my own. The only expertise I claim is troubleshooting. And I certainly would agree that they are useful in servicing. Of course in that situation I can think of a lot of switches that would be useful.

[Rick Erickson]

[no designer (who values his reputation) uses underrated capacitors. But the average amp tech doesn't know this.]

Funny- the last two Marshall amps I worked on - a JTM30 and a 6100 Anniversary model both were designed with caps that will be over-voltaged if the B+ is applied before the power tubes have warmed up. Adjusting the bias too cold will also run the caps into the danger zone. My shop has been seeing quite a few damaged filters in these amps lately.

[Bruce Gerard]

The standby sw should always be placed on the output of the rectifier (tube) or SS diodes just ahead of the choke (if used) & filters.