5E3 Ground Switch Help

Discussion in 'Amp Tech Center' started by TeleToTheRain, Aug 30, 2014.

  1. TeleToTheRain

    TeleToTheRain Tele-Holic

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    They guy I bought my chassis from has a huge cap wired from ground to one side of the ground switch and nothing coming off the other side :confused: So I assume it's not doing anything (not that it would be even if it were wired correctly since I have a 3 prong cord) but I want to remove it and use it as a Standby.

    I know the debate about not needing a Standby, but I'd like to put it in as long as it's not harmful.

    Not sure if I can use this switch or need a different type. I've read that it can just interrupt the B+ from the rectifier tube before the first cap, but then some say the cap has to be able to handle the spike... it may pop, something about CT, HT, something or other.

    I'm new to amps as you can tell.... just installed the proper transformer and noticed this was going on... and it's referred to as a "death cap" -- do I need to discharge it differently? As I said, I don't think it's doing anything at all wired the way it is now.

    any help would be welcome, thanks in advance!
     
  2. andyfromdenver

    andyfromdenver Friend of Leo's

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    Hi TTTR.
    I'll help you out cause of where you live :)

    It would be helpful to see some picks. If it's a similar sized switch to, say, your power switch it should be fine for standby. You might even keep the cap in place for pop reduction. All depends on what is seen though.

    Do you have a multimeter? Do you have some jumpers to drain the electrolytic caps?

    You're right, you simply interrupt the B+ after the rectifier.

    I saw your other thread about anchoring down the board. Need pics.

    Ttyl
     
  3. TeleToTheRain

    TeleToTheRain Tele-Holic

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    thanks, it can be rough down here! Yupp, got all the tools. actually, I don't have a capacitor/wire to drain the caps, I just power it up until the tubes are warm and then shut it off.

    I just want to remove the cap for now... don't think it will shock me, but as I said, I'm a noob and don't want to take any chances

    will post pics shortly
     
  4. TeleToTheRain

    TeleToTheRain Tele-Holic

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    image-3806413567.jpg



    image-812513296.jpg

    Sorry these probably don't help much. Posted board pic in that other thread.
     
  5. TeleToTheRain

    TeleToTheRain Tele-Holic

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    sorry to bump this, but would really like to get this sorted today if possible.

    the 100+ views can't all be to look at my wonderful photography.... ; ) speak up experts, I know you're out there, that's why I posted here and nowhere else. I'd be happy to provide more info if that helps

    thanks in advance!
     
  6. andyfromdenver

    andyfromdenver Friend of Leo's

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    That cap "can't" shock you on it's own with any power flowing through the amp.

    So as long as your certain the other end of the cap is going to ground. It looks like a .047 600v and you can keep it on there. Though some might not like this idea incase it failed short.

    Your switch is called a spst (single pole single throw)

    You can't hold me responsible to any damage to yourself or your amp.

    To turn it into standby:
    Run a wire from your rectifier pin 8 ONLY to one end of the standby. Run a wire from the other end of the standby (doesn't matter which one, but you can see from my pic that the rectifier wire and cap are on the same spot) to the point on the board that connects to the center tap of your output transformer and the first very large battery looking capacitor. On a standard 5e3 board it will be the second connection from the left. The first connection as you may or may not know is your power tubes' cathode resistor and cap. Don't accidentally connect it there unless you need to start a fire for some BBQ.

    You can completely remove that 473j orange drop cap as you desired; if you leave it on, it will reduce any "pop" in hitting the switch.

    Does that make sense? Use Weber's layout for guidance.


    PPS, you are soo going to get burned, probably sooner than later if you don't check your circuit for residual voltage when you "drain" it by warming the tubes. You're going to carelessly just flip it once quickly on and off or something and not think about it and get shocked.
    You need to check every time. It's your life however.
     

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  7. andyfromdenver

    andyfromdenver Friend of Leo's

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    Edit cause I can't easily edit my previous post from the iPhone. I think maybe if you're keeping the orange drop, you want it on the rectifier connection for it to be effective.

    Edit 2 in previous post that orange drop can't shock you "without" any power running through the amp
     
  8. TeleToTheRain

    TeleToTheRain Tele-Holic

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    Thanks for all the help fellas! And I am super anal about checking it with the multimeter before working on anything. I do need to just start draining them manually but I don't have a capacitor and I don't want it to arc.

    So the cap and switch I have should work for the standby.... That's great news! I'll check the numbers on it and repost just to confirm.

    Been trying to figure out if there is anything else I can use the switch for.... a bright switch maybe? I'm switching speakers today so it may do the trick but I wouldn't mind a light more presence in the top end.
     
  9. andyfromdenver

    andyfromdenver Friend of Leo's

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    Ok that's good. You use a resistor to drain them btw. A lower value like 100ohm will do it relatively fast. Or you can jumper to ground through one of the plate resistors (100ks over on the far right of the board) but that will take longer.
    As long as you're checking the big caps and it's under 9VDC, that's fine.


    I only use the bright channel #1, it's the "tangy-est". My hats off to ya for wanting more bright :)
    I can appreciate it.

    Yeah, if you don't think the standby will be very useful for you, I say just leave it off.
     
  10. Telenut62

    Telenut62 Poster Extraordinaire

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    You don't need a standby switch :D
     
  11. TeleToTheRain

    TeleToTheRain Tele-Holic

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    oops, duh, a resistor, yes.

    it's plenty bright in the bridge position with tone full up, but I thought I needed more until I swapped out the Fender Eminence for a Red Fang today.... sounds great and way more dynamic to my ears.

    yeah.... might just take out the cap and have the dummy switch there. why complicate things right? a line out could be cool, or maybe a switch to an attenuator down the road.

    maybe I'll just use it to screw with people... tell them its a mojo switch or something and rave about it when its switched on.
     
  12. TeleToTheRain

    TeleToTheRain Tele-Holic

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    one other question....

    I've read about turning the volume on the unused channel full up (or close to since it cuts out if it's all the way) and then the channel you're plugged into has a better sweep and it's cleaner, but when doing this there is a lot of white noise the higher I turn the unused channel vol. Is this normal?

    I do still have the 12AX7 that came with it in V1 cause I wanted a nice comparison for the AY I have ready for it. Have heard that can make it noisy as well.
     
  13. TeleToTheRain

    TeleToTheRain Tele-Holic

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    decided to just remove the cap and leave the dummy switch for now... keepin it simple. Ground switch is something of a conversation piece.
     
  14. andyfromdenver

    andyfromdenver Friend of Leo's

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    Yep that's normal. Just like any amp with nothing plugged in. If you max the volume you'll pick up the noise of life.
     
  15. TeleToTheRain

    TeleToTheRain Tele-Holic

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    Yeah, I hear that (literally!).... but what about when a guitar is plugged in?
     
  16. milocj

    milocj Friend of Leo's Ad Free Member

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    I'd have to test this out on mine because I usually run the unused normal channel closer to 10 than wide open for cleans, but if this is a kit build I would double check that the shorting jacks are wired correctly. Seems to be a common mistake and if one or more are wired wrong on the unused channel you'll get noise like having an unused guitar cord plugged in.
     
  17. TeleToTheRain

    TeleToTheRain Tele-Holic

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    Thanks, I appreciate it. I may have misread, I didn't have anything in the second channel, just the first, but when I turn up the second there's white noise. (which now that I think about it, isn't really that odd) I think if it's passed ten it shorts out.

    It is normal to have nothing or a muffled sound until about 3 on the volume and then it is relatively loud, correct? Seems like I can't get away from that phenomenon..... HRD had the wrong kind of pot, and this is the circuit... oh well.

    I will definitely check it as I've had to correct a couple things already. Can you point me in the right direction? (shorting jacks) Sorry I'm a total annoying noob with this stuff. Pics would be great if you got em handy. Thanks again!!
     
  18. TeleToTheRain

    TeleToTheRain Tele-Holic

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    Here's a few pics, hopefully they show enough. Don't crucify me too bad.... I inherited 90% of this. Definitely not as tidy as some I've seen, but I cleaned it up a bit and I don't know if I really want to go further just yet. Doubt anyone could just look at this and tell me if everything looks correct, but I appreciate some more eyes on it. It does play and sound good.

    image-3776217817.jpg


    image-2453133881.jpg


    image-2931034187.jpg


    image-1048579364.jpg


    image-3886906888.jpg
     
  19. milocj

    milocj Friend of Leo's Ad Free Member

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    The input jacks on amps have a grounding lug on them so that when you don't have anything plugged into an input they short out to ground and it keeps the amp quiet, otherwise it will sound like there's always a cord plugged into your unused jacks that doesn't have a guitar plugged into the other end of the cord and you get that hum.

    Is the amp quiet otherwise without anything plugged into the inputs and only a small increase in white noise as you turn it up? I just tried my build and there is almost no difference whatsoever if I plug into one channel and turn the other channel up until I get just about to 12, then it gets a bit quieter.

    I don't have a good picture of my 5E3 inputs, but if this picture shows up it should show you how the jacks should connect. Some people turn them so that the tip and sleeve of each channel's jacks touch each other and solder them that way and others use a jumper wire. I can tell that yours has a jumper, but I can't tell if they are wired correctly from that angle. Also look at the Weber layout linked below or do a Google search of "how to wire amplifier input switching jacks" and you should find some good images to check against your amp's wiring.

    https://www.google.com/search?q=how...sic-electronics-forum.com%2Ft13912%2F;226;227

    https://taweber.powweb.com/store/5e3_layout.jpg

    If the first link shows only two jacks, look to the right and see if there is a box of photos with multiple images in it. The second image in on the top left shows a 5E3 set of jacks wired up and "A" "B" "C" connections for where each lug goes.
     
  20. TeleToTheRain

    TeleToTheRain Tele-Holic

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    Thanks man! I will look into it some more, that's great info.

    Decided to add a couple wire straps and an angle for the lower back panel in case it gets kicked or something. (can only see the bottom leg in this pic)

    image-415095337.jpg
     
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