Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: goldtop1 on April 21, 2012, 11:10:31 am
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Just a quick question about the standby hookup. I am using Doug's layout for this build, and the parts list has one spst switch each for the power and standby. Looking at the layout,he has the HT lines separated on different poles on each side of the switch. Do I dare connect the HT lines together and put the on on side of the switch, or use a dpdt switch and separate them to the diodes? The spst switches I have , have only one pole on each side. :dontknow:
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Look at the Marshall 50-watt power supply diagram on Doug's information page. It shows using a DPST switch before the diodes. I recently re-built a 1974 Marshall Superlead and was able to re-use the original DPST standby switch. The parts list shows a SPST but both the power supply diagram and the Layout No. 1 diagram show using a DPST switch. I would use the DPST but maybe someone else on this forum could provide additional input.
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The Marshall schemos show (standby switch) using each side of the secondaries on each side of the switch, (DPDT) to the feed side of each side of the rectifier.
For standby switch, you can also use a big spst past the rectifier, or a dpdt using both sides of the switch in and out, to spread out the juice.
This way, has higher (DC) voltage on the switch, and is almost as safe, as the stock version. Many clones do it this way.
If done this way, use an over rated switch. 10 amp.
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Do I dare connect the HT lines together
ABSOLUTELY NOT! Unless you want to buy another PT.
Parts list is wrong. The standby switch is a DPST.
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Sluckey, that's kinda what I thought, on my other builds I use a DPDT to separate the leads, but thought I'd ask just the same!
This forum is the best, as far as knowledge and experience, and quick answers to the questions! The upmost thanks to all those who have responded to my questions.
Cheers, :occasion14: