Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: hesamadman on November 03, 2016, 07:26:54 am
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I originally had one question regarding channel switching relays. After doing some research I made a realization about something that I may need to address.
1. How important is it to have a capacitor in parallel with the diode for additional protection of spikes?
2. Something I have been working on and plan to use often is Dougs regulated DC board for the relays. These boards use a bridge rectifier and my 6.3 tap is referenced to ground. This will surely short out my rectifier wont it? What are my options with this? Im considering a separate transformer for the relays.
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1. Not important.
2. You can use Doug's relay power supply board but you must not connect any part of the supply or relays, or switches to chassis ground. The board has the negative side of the output labeled "grnd". DO NOT CONNECT TO CHASSIS GROUND. THIS MUST BE FLOATED.
If what I said doesn't make sense to you then you should just use a separate 6.3v AC source for the supply.
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Ok thanks Sluckey. My foot switch jack is an isolated jack. I haven't connected anything else to ground. In my first attempt to channel switching, I had some noise that wasnt insane, but it was rather loud. During playing it wasnt audible, but it was unacceptable. Trying to narrow that down as I have also bumped into some difference of opinion on the caps across the diode. I have not found any information leading toward it being necessary. I have only had one very reputable source say it is "sometimes" necessary.
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1. How important is it to have a capacitor in parallel with the diode for additional protection of spikes?
I've been here for 6+ years(?), have read every post during that time and I don't recall anyone here every having a problem with that.
Nor do I remember ever seeing it at the old Power Scaling forum/Kevin O'Connor (I read every post there) or in any of Kevins books (I have all of them) or in any other books I have. :dontknow:
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For those who may not know ..................... there is ALOT of excellent information, layouts, schematics etc.......
about relays in ARCHIVES: http://el34world.com/Forum/index.php?topic=14348.0 (http://el34world.com/Forum/index.php?topic=14348.0)
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https://www.youtube.com/watch?v=gqQ99s4Ywnw (https://www.youtube.com/watch?v=gqQ99s4Ywnw) :l2: :l2:
I've been working with learning relays and channel switching for about 6 months and had no idea this archive existed!
Thanks Tubenit! Really appreciate it. Footswitch stuff will come in hand too.
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I Tried to look thru the list and didn't see it . But we have to put the Geezer trick in there. As I have it labeled . He was looking for noise in one of his builds and clipped a 100 ohm resister from the power supply on the relay to ground killed the noise has saved me several times in my builds.
Thanks Bill