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1968 Japanese Guyatone GA-240 Tube Amp Issues

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  • 1968 Japanese Guyatone GA-240 Tube Amp Issues

    Hey Guys

    Here is the scoop:

    I just recapped my Guyatone 8w tube amp a few weeks back, got the tremolo working and all was good in the world (this thing sounds killer and LOUD with only a 10w 6" alnico speaker!).
    Now the amp had some mild humming issues and when turned on you could feel the vibration from the tranny.
    After the recap using the proper micro farad ratings and the voltage being equal to or higher in rating compared to the stock caps, I would get the odd loud honk/drone from the amp where I would lose guitar sound and it made a noise similar to touching the cord end with your thumb.

    Last night I decided to rewire it with new wiring i.e. vintage style cloth and proper heavier gauge heater wire as well (green).
    Each wire I replace was done via removing one end, soldering on the new wire, then removing the other end and completing the circuit via soldering on the new end.
    I wanted to be sure I did not mix up or cross anything in the process so I did each one by one.

    Big foolish unsafe move on my part is I had the amp plugged into one socket when testing it and ended up putting it into a different socket later on.
    As a result I looked at the prior outlet out of habit and thought "OK the amp is unplugged" and worked on it.
    I noticed the issue once I touched the soldering iron to the wire point soldered from the on/off/volume pot to the fuse and the amp light lit up and gave a tiny short quiet hum.
    I immediately unplugged it and continued wiring.

    After all the wiring was done I tested it out and I got no sound...just a mild hum as if it was on.
    After about 20 seconds of it being on i heard a slight sizzling and noticed a tiny stream of smoke coming out of the tranny, argh!
    My question is...did I fry the tranny when I touched that wire while plugged in(??), was the tranny on its way out and it was just coincidence due to the previously mentioned issues, or have I (somehow??) crossed a wire somewhere and I am overloading the tranny thus getting no sound etc?

    Can any of you see anything out of place via the photos below?
    Also, do I really need that new 450v cap wired to the 240v?
    I just wired it up as the old canned cap was originally but I have the main wire on the 117v tranny lug.

    Your input and help is appreciated for this lowly noob!





  • #2
    No clues hey?
    Any ideas on what would be a good candidate for a tranny replacement for this then?

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