• 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.

help please

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#22
Hello Gorbayov,

I don't want to offend you, but if I were you, I'd find a local shop that sells amateur radio equipment and talk to the manager about getting someone to help you. Usually there's some local radio operators that are very familiar with vacuum tube safety & construction.

Without a good schematic and you being unfamiliar with the design, I fear you may really have a difficult time fixing the preamp.
 
#23
i am not offended dont worry about that.

i just thought it would be easy to know where i should connect the input signal to.
i guess i was wrong..
the problem is that i live pretty far from anywhere with shops like you are talking about.

im going to try and connect it to pin 9 because its the only pin i see a wire that got disconnected from something and its a flat wire and that the only flat wires are coming from the inputs, and this pin is only connected to the ground with a resistor like gregg said..
i'll try to connect it to a microphone that i dont care about first before i try the guitar so i wont harm my guitar.
but i might wait for tomorrow to do it, and maybe someone can add something that you guys didnt tell me already..

thank you all, especially gregg, you helped me to understand a thing or two, even if its not enough to be sure about the problem..
 
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#27
I can only offer advice. It's entirely up to you if you decide to ignore what two people have told you in this thread. All I'll do now is refer you to this thread in the hope that you read it.

http://www.diyaudio.com/forums/tubes-valves/30172-safety-practices-general-ultra-high-voltage.html

DrDeville said:
  • Any voltage can be deadly. :hot: :RIP:
  • Amplifiers are dangerous--each person (me included) is responsible for deciding if they are willing to risk their life, and for ensuring that whatever information they receive is correct
  • This forum and its members accept no responsibility for any death, injury or property damage that result from any of these suggestions--your safety is your own responsibility.

  • Make sure any charge-storing devices remain discharged while working on the equipment
  • Avoid creating a circuit which would pass current through the heart.

From those rules of thumb, I can think of these specific practices:

  1. Put a drain load across all significant charge-storage devices (e.g. B+), and leave them there for the duration of your work--some devices can redevelop voltage if left unloaded.
  2. Verify that all charge-storing devices are discharged before starting work.
  3. Always work with only one hand--keep the other hand in your pocket.
  4. Use hook probe for secure connections and to avoid shorts.
  5. Wear rubber gloves and rubber soled shoes--no bare feet or socks.
  6. Make sure your design has the chassis safety grounded--connected to the ground wire of the power plug.
Click to expand...
 
#33
well no need for apologize..
everyone knows what he knows, and you cant judge someone's skills over the internet, you can only try 🙂
and im glad about the warnings, you can never warn enough.

i can just tell you one thing, when someone says i cant do something, i will do it eventually, even if i need to think and read too much..
 
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