5E3 Tweed Deluxe Project Pics (Part 2)...need troubleshooting tips

Discussion in 'Amps and Cabs' started by jpervin, Jul 4, 2006.


  1. jpervin

    jpervin Supporting Member

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    A few weeks ago I posted pics of my 5E3 tweed Deluxe project, which is my first time building an amp. Here's the original thread...

    http://www.thegearpage.net/board/showthread.php?t=147881&highlight=Deluxe

    Today (July 4th) I finally finished it. When I plugged it in, turned on the power switch, then a few minutes later turned on the standby switch, I got...nothing...except for a wisp of smoke from the chassis. No sparks, no fire...but no sound either. Also, there was a faint glow coming from the rectifier tube, but the preamp and power tubes did not light up they remained cold. I have absolutely no experience in amp troubleshooting, but I did remove the upper back panel and noticed that some of the ground wires that were soldered to the brass grounding plate (attached to the pots inside the chassis) somehow came loose. I can't say I'm not entirely disappointed (although I did double check every connection before I installed the chassis), since this was my first time building an amp. So it looks like I'll be making a trip to an amp tech. In the meantime, anybody have any suggestions?

    Here's some pics of the finished amp. If only it worked...then it would truly be finished! :(

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  2. garfight

    garfight Member

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    i can't really see the guts too well but from what you described it sounds like you have an issue with your heater circuit.recheck all your wires going to pins 4,5 and 9 on your preamp tubes and make sure they are all connected well.if that doesn't fix it -shoot some more close up gut pictures and repost em.
     
  3. sdgvintage

    sdgvintage Member

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    Your heater wires must be shorting out on something else.

    Probably a good lesson for noobs building amps is how to power em up for the 1st time.
    1. Check all your wiring.
    2. Check all your wiring.
    3. Check all your wiring.
    4. With no tubes in turn it on.
    5. Turn it off.
    6. Smell for smoke.
    7. With the rectifier in, turn it on, with the standby, then off, then the standby closed turn it on again.
    8. Measure voltages on the plate pins. Pins 1 and 6 of your preamps.
    8. smell for smoke.
    9. put your power tubes in.
    10. smell for smoke. Measure bias. (its probably a good idea to put down the extra couple of bucks to get the weber bias rite)
    11. preamps in, measure bias again.
    12. any smoke yet?
     
  4. pbradt

    pbradt Senior Member

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    1. QUADRUPLE check your wiring. Trace down each wire separately and make sure they go where they're supposed to. In my Champ build I did not do this before powering up and I had no voltage at pin 1 of the preamp tube on first power-up. OOPS.

    2. Did you power up first without the tubes? Check the voltages at the rectifier tube connections, WITHOUT the tube. Without the tube in there, they will be a little high but you have to see that your voltages there are correct.

    3. Make sure you hook up a speaker before firing up the power tubes. Check all your voltages at each tube.

    Finally, once you've installed the rectifier tube, make damn sure you're checking all voltages with one hand behind your back.

    Edit: sdgvintage said it better than I.
     
  5. hasserl

    hasserl Member

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    If you hav e no experience troubleshooting tube amps it makes it difficult to help you out. Re the failed solder joints on the brass plate, it is next to im;possible to solder anything to that plate after it is installed. The chassis just sucks all the heat away from it. I've got a 100 watt Hexacon iron with a nice big flat tip and I can barely get it to solder to that plate. It's best to solder your ground wires to the plate before you mount it. Or at least to flow some puddles of solder to the plate where you will want to mount the ground wires later. Anyway, you're going to have to get those ground wires soldered back down somehow, you may have to go out and get a bigger iron.

    Second, if the tubes are not lighting you need to check your filament voltage at the tubes, and in fact you should be checking & recording all the voltages. If you want help troubleshooting it you need to do the basics first, then you'd probably have better luck posting for help in the Amp Technical board or over at the Weber kit board or the 5E3 board.
     
  6. jpervin

    jpervin Supporting Member

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    Any idea what they'd be shorting out on?

    So, if I do another wiring check and everything seems ok, when I go to turn the amp on without the tubes (#4), I'm assuming you mean the usual power/standby on then immediately standby/power off? For #8, I'm assuming you use a digital multimeter to check the pins, and also check bias (#10 & #11)?
    I have a DMM (though I've never used it) but maybe it would be a good idea to get a Bias Rite...
     
  7. jpervin

    jpervin Supporting Member

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    Good thinking. I have a Champ that I can test them in.
     
  8. pbradt

    pbradt Senior Member

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    Without seeing pictures of the amp guts, it's impossible to say.

    A bias rite isn't what you need here. You have to check to see that ALL your voltages at various locations are correct. The multi-meter is what you want to use. If your instructions do not include these voltages, call your supplier and see if they can help, otherwise, take it to a tech who knows what they're doing.

    Before you power up, drain your filter caps. If you don't know how to drain your filter caps, again, take your project to a tech and have him finish it because you are in DANGER. Your filter caps hold enough electricity to KILL you.

    However, in the interest of safe amp building and powering up, I offer this how-to. I disclaim any and all responsibility regarding the proper execution of this procedure.

    Solder a three-inch piece of wire to an insulated alligator clip. Solder the other end of the wire to one lead of a 10-watt, 10K resistor.

    Take an identical piece of wire and solder it to another insulated alligator clip. Take the other end of that wire and solder it to the other end of the same resistor you've already soldered up.

    WITHOUT USING BOTH HANDS, attach one alligator clip to the positive end of one of the filter caps, doesn't matter which one.

    Take the other alligator clip, BY THE INSULATION, and attach it to the chassis. Go have a snack. Wait 10-15 minutes.

    Only NOW is your amp safe to power up, as long as the rectifier is NOT in the amp. but if you don't know how to check the voltages, you have no business working further on the amp, as you simply don't know what you're doing. I'm sorry to be harsh, but reading what you've written, it seems as if you're in over your head.

    I strongly recommend you take you project to a qualified tech for completion.
     
  9. jpervin

    jpervin Supporting Member

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    ...and all of the tubes from the 5E3 are good when I tested them in the Champ. So I know that's not it.
     
  10. tedm

    tedm Gold Supporting Member

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    go to www.ampage.org and post on the 5e3 forum.

    also:

    1. Make sure your power and standby switches and fuse and lamp assembly are wired correctly and safely.

    2. Learn to use a multimeter. You should have measured 6.3 VAC on the heater pins of the preamp and power tubes, and 5.0 VAC on the 5Y3GT filament pins before ever turning off standby.


     
  11. hasserl

    hasserl Member

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    I'm sorry, but why would he need to drain the filter caps before he fires it up? That makes no sense, and is not necessary. YOu should have a harness for drainin the caps available, so go ahead and fashion one. But at this stage you don't need ot drain them.

    What you do need to do is check all your voltages, and understand why they are what they are. That means you need to do a little studying. Start surfing the net, google is your best friend. SPend a couple of hours reading, and study your schematic, and figure out how all those components work and what they are doing in the circuit. The take you voltag readings and figure it out.

    Again, this aint the best board to get technical help on, you'd do better on the amp technical board, but you'd get even better help on the Weber AMp board, the Kit Building board, Ampgage discussion board or the 5E3 board.

    But the guys are gonna expect you to do your part. Don't expect people to all your thinking for you. Take some time to educate yourself, that's what this kit building is all about.
     
  12. WaltC

    WaltC Member

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    Well first, I don't see any wires running from the pilot light (wired from the 6.3V tap on the PT) to the other tube sockets (should go from the light to the 1st 6V6 then to the next 6V6 and then on to the 12AX7s in parallel). You may have the wire there but I can't see it in any of the pictures. No wires, no power, no lights in the tubes, no work....

    Second. Make sure that you have the wires going to the right pins on the rectifier. 5V taps to pins 2 & 8 and HT wires (red) to pins 4 & 6. the rectified DC voltage is usually taken off of pin 8 on the rectifier. Make sure all those are correct. Pull all your tubes except the rectifier (once you've verified the wires are correct) and then measure the voltages you get between pins 4/6, AC between 2/8 and DC between pin 8 and ground and let us know what you get.

    that's a start.

    Walt Campbell
    Campbell Sound
    http://www.campbellsound.com/
     
  13. jpervin

    jpervin Supporting Member

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    Well, I decided to take this amp to an amp tech (Bruce Marcolina in Chestnut Hill, PA) to find out why it would not fire up. Turns out that I had crossed a few wires on all of the input and speaker jacks and the ground wires needed to be rerouted. Other than that and a couple of cold solder joints, the amp was fine. When Bruce turned the amp on and hit the first note with his Tele, this big smile crossed my face. It sounds fabulous!! And LOUD!!! The Weber speaker sounds a little stiff but that'll change when it breaks in. Nice, early breakup, just like a tweed Deluxe should.

    I can't recommend Bruce Marcolina highly enough! Not only did he do a great job in pinpointing what the problems were, but he was very patient and went through the amp with me and explained how everything tied together electrically. And, of course we talked about amps, guitars, etc. in general. He's a helluva nice guy to boot! Highly recommended!!!
     
  14. Mastervolume

    Mastervolume Member

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    sweet I am glad it worked out!
     
  15. jpervin

    jpervin Supporting Member

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    Me too!

    I'm already gassing to build another amp! :drool ...with lessons learned for next time, of course.
     

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