Plate blue wire from OT

  • Ok I checked all again

    The current flows within the amp with the bulb limiter I can see the caps on power supply board and the other board getting about 82 volts

    Once I switch off the amp the volts gradually reduce to nearly 0

    Davide Violante

    Rockers&&Rocks

    http://www.rockers.rocks

    Schoonenburgsingel 176

    2135GE Hooffdorp

    Netherlands

  • Congrats! Sounds like everything is okay. Now in with the tubes and keep us updated! Or else we get worried.

    "Perfektion ist nicht dann erreicht, wenn es nichts mehr hinzuzufügen gibt, sondern wenn man nichts mehr weglassen kann."
    - Antoine de Saint-Exupéry

  • Congrats! Sounds like everything is okay. Now in with the tubes and keep us updated! Or else we get worried.

    Thanks no worries all is ok with me :) i,m using all precautions safety glass, no sticking my hands on it but using a wooden stick to touch parts. I removed the current limiter, the amp on power switch, after few seconds standby switch on I can see still 82 volts on C22 cap on power board that is not normal I should get 300 volts isn't?

    Also connected guitar and cabinet speaker but no sound

    Davide Violante

    Rockers&&Rocks

    http://www.rockers.rocks

    Schoonenburgsingel 176

    2135GE Hooffdorp

    Netherlands

  • You

    I didn't connect the speaker I don't wanna burn them out lol

    You have to connect a speaker to the output or else you risk damaging your OT and power tubes! The power tubes have to see a load reflected to them via the OT!

    but the tubes do not gloom

    If the tubes don't glow then there is definitely a problem with the heater wiring. Even if everything on your board was wrong (except having a short and blowing a fuse) the tubes would still glow if the heater was connected correctly.


    I would suggest the following: Turn off the amp and discharge the capacitors in the PSU. Then check if there is connection between the both ends of the heater wiring. Sometimes the PT wires are covered with some protective coating that needs to be scraped off before soldering.

    Greets, Max

    "Perfektion ist nicht dann erreicht, wenn es nichts mehr hinzuzufügen gibt, sondern wenn man nichts mehr weglassen kann."
    - Antoine de Saint-Exupéry

  • ok let's try that, I have connected the speaker at the end but no sound. one more thing I could think of, is the heater wires from PT to Power Bard are maybe ok, but then from there underneath the board I soldered the heater wire on eyelet, it could be that soldering there isn't ok. checking now for continuity

    Davide Violante

    Rockers&&Rocks

    http://www.rockers.rocks

    Schoonenburgsingel 176

    2135GE Hooffdorp

    Netherlands

  • Wait... ehm... you know that your Tubes are not working, but you are checking if you get sound?

    Why do you do the opposite of what you should?

  • Hi Max I think that might be the problem on OT

    The heater wires red and white, I think one of the is connected don the wrong lug:

    Check this out:

    There are two thick copper wire coming from the inner OT but the red wire isn't connected to that lug but to the one above which has nothing.

    ???? What do you think

    Davide Violante

    Rockers&&Rocks

    http://www.rockers.rocks

    Schoonenburgsingel 176

    2135GE Hooffdorp

    Netherlands

  • I think there is rarely any solder on those joints. Did you measure at least the resistance between those lugs before soldering?

  • What does the multimeter say? Is there continuity from white to red wires at the PT?

    I think there is a chapter in the Build Documentation that came along with your kit explaining that. And there should also be a chart for startup with detailed descriptions of the measurements you should perform with reference values. Haven't built an A15 myself so I am not sure, but with the smaller amps like G3 Blues there was a very in depth explaination on what and how and where to measure the voltages as well as instructions regarding the wire coating. Check the manual again, please. I don't have it here.

    "Perfektion ist nicht dann erreicht, wenn es nichts mehr hinzuzufügen gibt, sondern wenn man nichts mehr weglassen kann."
    - Antoine de Saint-Exupéry

  • The thick 2 copper wires comming out ftom PT are the heater Winding,there must be the heater connected !

    If the Heater wires than correctly connected and the Heater still diddn´t work,look at the Solder Joints in the Eyeletts,what i told you in one post.

    And yes,please use your Multimeter to find out if you are right with the Heater connection.

  • Think about it like this:

    The multimeter is capable of measuring single Ohms, which is what you expect even with a long wire and no further resistance... up to at least one million Ohm which is already in the region of the resistance of your own body. (so keep in mind, when measuring MegaOhm, don't touch anything even with low-voltage devices)

    Knowing how a transformer is working internally, it is pretty clear, that you expect the lowest resistance at the lugs with the lowest voltage and the highest resistance at the lugs with the highest voltage. Not only, because the leads are longer, but also because the leads with the lower voltage carry more ampere and thus could heat up much faster if there is any reasonable resistance. So those low-voltage leads are thicker to have lower resistance.

  • Use crocodile clamps and don't hold both ends of the tips in your hands. One hand in the pocket, one hand for measurement. Or even better: No hands on the multimeter ;)

    "Perfektion ist nicht dann erreicht, wenn es nichts mehr hinzuzufügen gibt, sondern wenn man nichts mehr weglassen kann."
    - Antoine de Saint-Exupéry

  • Use crocodile clamps and don't hold both ends of the tips in your hands. One hand in the pocket, one hand for measurement. Or even better: No hands on the multimeter ;)

    Yes I am doing this way don't touch anything with hand I use wooden stick, I use alligator clamps black to earth and red to + to check caps voltages other hand in pocket like you said , indeed I do it exactly like you said

    Davide Violante

    Rockers&&Rocks

    http://www.rockers.rocks

    Schoonenburgsingel 176

    2135GE Hooffdorp

    Netherlands

  • What does the multimeter say? Is there continuity from white to red wires at the PT?

    I think there is a chapter in the Build Documentation that came along with your kit explaining that. And there should also be a chart for startup with detailed descriptions of the measurements you should perform with reference values. Haven't built an A15 myself so I am not sure, but with the smaller amps like G3 Blues there was a very in depth explaination on what and how and where to measure the voltages as well as instructions regarding the wire coating. Check the manual again, please. I don't have it here.

    There is continuity from white to red at the PT I have checked the wire previously was not connected on the copper wind at the PT, only the white but not the red but I have rectified that now, but I turned on the amp using again current limiter, but I don't see tubes valve glowing hmmm so need to recheck everything again something isn't right somewhere

    Davide Violante

    Rockers&&Rocks

    http://www.rockers.rocks

    Schoonenburgsingel 176

    2135GE Hooffdorp

    Netherlands

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