• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

SimpleSE and Switches

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I am starting to put together a SimpleSE amplifier from TubeLab.com, and I had a couple questions about the following switches on the schematic:

1) Triode / Ultra-linear switch
2) Cathode Feedback On/Off
3) Solid State / Tube Rectifier

Is it safe to toggle these switches with the amplifier on and playing music? I am trying to build something that is as kid-safe as possible.

If it is safe to change these on-the-fly, I would like to use using relays to control them. Can I use the 5v secondary with a rectifier/filter caps to power the relays? Do I need to use relays that are rated for some high voltage (like 500V)?

Thanks in advance,
--Tom
 
I agree with adason. Definitely dont' mess with the rectifier while powered up. The safest thing in my opinion is to power off the amp, let it cool, change your settings, and then power up again.

I've got little kids too, so I put all the switches on the top of the chassis. When I put the cover on, nobody can fool with the switches, except for the power switch. I put that on the back. Outta sight, outta mind. That and I keep the amp up real high off the floor so they can't yank out the speaker cables. It looks a bit crazy with my folded horn speakers upside down way high up off the floor too.
 
G'Day Tom.

Just in case you have not seen the advice on the tubelab site, dont build the amp with a standby switch, it may end up frying your rectifiers. I would recommend just using a valve rectifier and don't even bother with the SS diodes.

For the other switches, I just used regular 240v ac rated toggle switches, they work fine. Also, I know that you should not switch "on the fly", but I do for ultralinear/triode and cathode feedback on/off and have had no problems doing this. If your kids do it occasionally, it should not be a problem. I have had my amp for about a year now, so if that would fry things, I expect it would have happened by now ;)

Good luck withthe build!

Chris
 
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