3 ms·

I built my tube amplifier (along with some effects pedals) for my electric guitar at 17. Now that I have kids, I wonder how my folks let me work with 400V of e

I built my tube amplifier (along with some effects pedals) for my electric guitar at 17. Now that I have kids, I wonder how my folks let me work with 400V of electricity and not freak out. Makes me wonder what kind of weird things my kids are going to get into.

quickthrower2 3y ago
400v? what that what your mains was packing?
- mnw21cam 3y ago
  Thermionic valves require a high voltage, because their principle of operation is accelerating electrons across a vacuum.
- jacquesm 3y ago
  Just a rectifier and a cap and you're there from regular household current (not safe without galvanic isolation!!). But with a simple transformer you can go way higher. Some of the end stages on tube systems I had when I was a kid would sit at 500V when idling (EL44). Usually as soon as you see a tube with a cap on top you know you have something pretty high voltage.
- franky47 3y ago
  No, mains runs at 230V in Europe, but as said by sibling comments, after the power transformer and rectification, HT1 (the primary high tension power bus, usually feeding the tubes in the power section) can get in the 300-500V range in some amp designs. I knew from schematics and calculations it'd be about this high, but seeing the actual 400V value on my cheap multimeter sent shivers down my spine. Also I remember accidentally shorting the wrong wires while taking a measurement and blowing a fuse. Fun times!
  - jacquesm 3y ago
    Wait until you touch a live anode, that will send shivers down your spine ;)
mnw21cam 3y ago
I built my stereo at age 12, then followed it up with a (much larger) bass amplifier for my bass guitar when I was 14, and a mixer/effects box at 15. Of course they linked together, using the bass amplifier as a sub-woofer. I didn't have to deal with as high a voltage as you, just the 240V mains supply, and then the +-70V supply to the bass amp circuitry. I think kids these days are much more likely to do something digital than build things like this from discrete components.
- jacquesm 3y ago
  Indeed, and I consider that to be a huge loss. Real world skills are important skills. Just as important as digital skills but financially we seem to think otherwise.
bombcar 3y ago
From my experience the kid can have more understanding of what is going on than the parents, and they may not realize the risk.

quickthrower2 3y ago

400v? what that what your mains was packing?

mnw21cam 3y ago
Thermionic valves require a high voltage, because their principle of operation is accelerating electrons across a vacuum.
jacquesm 3y ago
Just a rectifier and a cap and you're there from regular household current (not safe without galvanic isolation!!). But with a simple transformer you can go way higher. Some of the end stages on tube systems I had when I was a kid would sit at 500V when idling (EL44). Usually as soon as you see a tube with a cap on top you know you have something pretty high voltage.
franky47 3y ago
No, mains runs at 230V in Europe, but as said by sibling comments, after the power transformer and rectification, HT1 (the primary high tension power bus, usually feeding the tubes in the power section) can get in the 300-500V range in some amp designs. I knew from schematics and calculations it'd be about this high, but seeing the actual 400V value on my cheap multimeter sent shivers down my spine. Also I remember accidentally shorting the wrong wires while taking a measurement and blowing a fuse. Fun times!
- jacquesm 3y ago
  Wait until you touch a live anode, that will send shivers down your spine ;)

mnw21cam 3y ago

I built my stereo at age 12, then followed it up with a (much larger) bass amplifier for my bass guitar when I was 14, and a mixer/effects box at 15. Of course they linked together, using the bass amplifier as a sub-woofer. I didn't have to deal with as high a voltage as you, just the 240V mains supply, and then the +-70V supply to the bass amp circuitry. I think kids these days are much more likely to do something digital than build things like this from discrete components.

jacquesm 3y ago
Indeed, and I consider that to be a huge loss. Real world skills are important skills. Just as important as digital skills but financially we seem to think otherwise.

bombcar 3y ago

From my experience the kid can have more understanding of what is going on than the parents, and they may not realize the risk.