Spitfire clone build

Discussion in 'Shock Brother's DIY Amps' started by JacknCocaine, Oct 2, 2019.

  1. JacknCocaine

    JacknCocaine TDPRI Member

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  2. JacknCocaine

    JacknCocaine TDPRI Member

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    [​IMG]
    Here is the schematic for reference. I bought the pre-loaded board from them.
     
  3. KT89

    KT89 TDPRI Member

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    That's not a schematic, that's the layout. I recommend getting hold of a schematic and working from that while comparing to the layout. Understanding how all the components work electrically with the lead connections will be very important if you need to debug (and so you don't hurt yourself).
     
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  4. JacknCocaine

    JacknCocaine TDPRI Member

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    I understand your concern, but I promise I have a pretty good understanding of how it works. I'm taking it to an amp tech I know before I plug it into the wall, but I didn't want to pay him to build the amp for me. I'm pretty sure the top of the post that would be the "on" position is positive and the post by "off" is neutral. I just didn't understand the layout diagram from Watts. I'm also not 100% on the input jacks. I know it's high gain and low gain, but I wasn't sure which posts were which. I also didn't know if the two post was mono and the three post was stereo. The layout diagram is somewhat lackluster.
     
  5. Wally

    Wally Telefied Ad Free Member

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    That layout describes exactly how to wire the AC voltage source and the input jack. Respectfully, if you don’t understand the layout, imho you are contemplating stepping onto a professional football field without any prior knowledge of the game nor any physical or mental reparation for the battle that will ensue. The red-print disclaimer in the lower right hand corner of the layout will relieve Watts Tube Audio of any responsibility for what can happen in such a situation. I will at this time also decline to accept any responsibility for whatever you may do from here on.
    The Ac input cord should have three wires...black/hot, white/neutral, and green/ground. The layout hows the green going to chassis ground. The white is fed to one end of the PT primary and also to one side of that 120VAC pilot lamp. The black hot wire runs through the fuse to the switch and then to both the lamp and the other en pd of the PT primary.
    I will observe that most people building kits are far less hesitant than I was to dive into these amps. I read a great deal, studied schematics and layouts as well as tube pinouts...and read some more before ever going inside an amp. This work is not as simple as the ease of internet info and kits might make it seem. Good luck with it......and I accept no responsibility should you proceed but leave you with this thought.....there is danger ahead....and Jack and cocaine might make the endeavor even more hazardous, ime.
    Been there, done that....(;^)
     
    Last edited: Oct 2, 2019
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  6. Wally

    Wally Telefied Ad Free Member

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    That input jack with three lugs is a shorting jack...and will be your higher gain input. The other input will have a 6db cut.
     
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  7. JacknCocaine

    JacknCocaine TDPRI Member

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    I appreciate the information, but I'm asking about the components, not the layout. How do I test the components with a multimeter without supplying voltage to the components to find the positive and neutral leads to make sure I don't install the power and standby switch backwards? I promise I'm taking proper safety precautions, at least until my life insurance kicks in!
     
  8. jhundt

    jhundt Doctor of Teleocity

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    this is a joke, right?
     
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  9. Wally

    Wally Telefied Ad Free Member

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    Okay...I’ll do one more. It matters not to which pole on the switch you attach the ‘in’ or the ‘out’. The switch merely makes or breaks continuity...turns the circuit on and off.

    If you don't Mind, I’ll make a suggestion. Pay your tech to guide you through the build and explain these simple but important things. I have no idea what he would charge for that....maybe some Jack and cocaine??? I grew up a mechanic’s son back in the early ‘60’s. On the wall was a sign that read: Labor-$10 per hour. If you ask questions-$50. If you want to watch-$100 per hour.
     
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  10. JacknCocaine

    JacknCocaine TDPRI Member

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    I may do some more homework, but I might have to do that. I'm almost done with the build, I only have a couple things I'm not 100% on. I just wanted to make sure the circuit was "open" when the switch was in the on position. I bought switches that are up and down instead of side by side. I really do appreciate the information, thank you! I'll upload a video when I'm done and I'll buy you a round if you're ever in town haha
     
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  11. Wally

    Wally Telefied Ad Free Member

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    Actually, when a circuit is ‘open’ the connection has been broken. The current flows when the circuit is ‘closed’ by that switch.
    Good luck with it...and give us some pictures.
    One of the best liquors I have ever had was some ‘shine from Alabama. It was like hot but smooth butterscotch.
     
  12. JacknCocaine

    JacknCocaine TDPRI Member

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    Thank you, I'm trying to learn. It's definitely more work than I thought it would be! I'll definitely upload some pictures for sure. We have some pretty good shine down here, especially the apple pie variety. It's good, but it'll sneak up on you!
     
  13. BigDaddy23

    BigDaddy23 Tele-Meister

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    Hey mate - This looks like an interesting build! Can u post the schematic as well?

    Just take it slow and verify all your connections as you go. Mark them off the layout and schematic, check their continuity. Have a look at other builds so you can get a good idea of lead dress and positioning.
     
  14. KT89

    KT89 TDPRI Member

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    You are going to kill yourself. Make a few pedals before taking on an amp I promise you're overlooking so many things. These voltages and especially the currents aren't joking around and you don't seem like you have the knowledge to take this project on. How much do you know about filter cap discharge? Do you know standard AC wall connections? I'm not saying it can't be done, but the things that can go wrong in a tube amp are often once and for all type things. At least get some supervision from the old lady or something so she can call 911.
     
  15. Wally

    Wally Telefied Ad Free Member

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    One hand behind your back when you have the thing fired up. Hopefully, your tech will give you full warning and guidance when he helps you bring the amp online. If he doesn’t have a current limiter, build two of those and give the tech one when you take the amp to him.
     
  16. Nickfl

    Nickfl Tele-Afflicted

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    Are you just trying to figure out when the switch is "off" and when it is"on"? If so, set your multi meter to read resistance (or continuity of it has that function) and clip the leads to the switch terminals. If the meter reads open it is in the "off" position, if it reads 0 ohms, it is in the "on" position. Flip the switch and it should reverse.

    Do this test with the component out of the circuit. And whatever you do, don't power this thing up without proper supervision, you'll need to learn a lot more before you're ready for that.
     
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  17. JacknCocaine

    JacknCocaine TDPRI Member

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    I wasn't sure if toggle switches needed to be oriented for polarity. I read through some old EE textbooks and found that polarity isn't an issue, they just break the circuit. I had a blonde moment, sorry! I also didn't know about shorting jacks, thanks Wally! I do know how to discharge capacitors, how to check for shorts, one hand only, and I won't plug it in to an outlet without a tech present. I promise I won't kill myself! I'm just trying to learn and do for myself. We all started somewhere, right?
     
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  18. zook

    zook Friend of Leo's

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    ...If you worked on it first $200 per hour.
     
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  19. Wally

    Wally Telefied Ad Free Member

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    Ain’t it the truth!!!
     
  20. JacknCocaine

    JacknCocaine TDPRI Member

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    Hey guys, I'm not dead! Took it to my tech. He laughed, and said he was surprised it worked. No cold solder joints, no shorts, and all values are correct. It sounded phenomenal, and louder than I thought it would. I forgot to take a video. I'll take a video tomorrow after work. Thank you everyone for your help and advice!
     
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