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Thread: Ampeg Gemini 1 Repair/upgrade

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    I'm dang-ol brewing, man! Boomhauer's Avatar
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    Default Ampeg Gemini 1 Repair/upgrade

    I built a website for someone and bartered for an Ampeg Gemini 1 combo amp. Its a great sounding amp and in great shape. I would like to replace the speaker soon, but right now I need to add a nuetral ground to the power cord.

    Anyone know exactly where to solder the nuetral wire to the amp?

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    Chief MLF Inspector Milf Man's Avatar
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    Typically, if it does not have a 3 wire plug it very well might not need one.

    Have a schematic I can look at?

    If retrofitting an old 2 wire unit, chassis ground and neutral would be considered the same thing and could be wired as such.

    Cheers,

    MILF Man
    Celebrating my 33rd year of Homebrewing.

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    Hellhound On My Ale BlindLemonLars's Avatar
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    I install 3-wire cords on ALL old amps I acquire or work on. I'd bolt the ground lead right to the chassis, there is probably a grounding lug inside...or one of the power transformer bolts would be a good place as well. The neutral lead should go to one side of the power xformer, and the hot should be wired to the fuse holder, power switch and finally the other side of the primary.

    I believe that amp has a "ground reverse" or "hum" switch, it's there to toggle a small capacitor between the two AC wires and ground. I always snip this capacitor out, on old amps they frequently fail with an internal short and then one switch position will make the chassis hot with respect to ground. Bad mojo! You're much better off and safer with a properly grounded chassis and with a correctly wired 3-wire cord there is no need for that dangerous switch.

    When I built my Deluxe Reverb clone, I put a switch in for authenticity but didn't wire it up.
    Last edited by BlindLemonLars; 07-13-2011 at 08:50 PM.
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    Jewsus Lerxst's Avatar
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    Quote Originally Posted by Milf Man View Post
    Typically, if it does not have a 3 wire plug it very well might not need one.

    Have a schematic I can look at?

    If retrofitting an old 2 wire unit, chassis ground and neutral would be considered the same thing and could be wired as such.

    Cheers,

    MILF Man
    You must be one of those guys that liked sticking forks and paper clips into wall outlets or licking 9v batteries as a kid

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    Chief MLF Inspector Milf Man's Avatar
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    Quote Originally Posted by k4df4l View Post
    You must be one of those guys that liked sticking forks and paper clips into wall outlets or licking 9v batteries as a kid
    An early pic of me doing an experiment -



    Cheers,

    MILF Man
    Celebrating my 33rd year of Homebrewing.

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    Hellhound On My Ale BlindLemonLars's Avatar
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    Quote Originally Posted by Milf Man View Post
    An early pic of me doing an experiment -
    Is this your dog? ;-)

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    Pog mo thoin! JackHackett's Avatar
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    Good answer BLL...wouldn't want anyone to probe the outer limits of human capacitence!!

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    Hi Blind Lemon. FYI, I still own a 1966 Gemini 1 that my Father bought for me new that year. I was 15 and in a rock n roll garage band with mostly homemade amps that he made. I can tell you it does NOT have a reverse ground switch. Back then you could unplug it and turn the plug 180 degrees and eliminate hum. And try to eliminate shocks off the microphone. I still use it in my current band and it has a new 3 prong plug that is properly grounded. I'm sorry I can't say how it was done as It was done for me by a tech. Nice to chat with you. I'm new tonight to the board. I found this thread on Google when searching Ampeg Gemini 1 amps.

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    I'm dang-ol brewing, man! Boomhauer's Avatar
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    I forgot about this thread. I ended up selling my Ampeg Gemini 1 and buying a Crate half stack. The cool part is that I sold the Ampeg to Richard Fortus of Guns n Roses. Really cool guy. He found my ad on Craig's list and we met at a gas station in my town. We talked about music and equipment for about half an hour... he signed some stuff for my kids and talked to them for a while. Then he took my son aside and gave him some guitar playing tips. I really can't say enough about how genuinely nice he was.

    He even sent me an email the next day to compliment me on how cool he thought my kids were. I hated to see the amp go, but it was worth it to meet him and have my kids meet him.

    Sent via telepathy

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    Hellhound On My Ale BlindLemonLars's Avatar
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    Quote Originally Posted by usd335 View Post
    Hi Blind Lemon. FYI, I still own a 1966 Gemini 1 that my Father bought for me new that year. I was 15 and in a rock n roll garage band with mostly homemade amps that he made. I can tell you it does NOT have a reverse ground switch. Back then you could unplug it and turn the plug 180 degrees and eliminate hum. And try to eliminate shocks off the microphone. I still use it in my current band and it has a new 3 prong plug that is properly grounded. I'm sorry I can't say how it was done as It was done for me by a tech. Nice to chat with you. I'm new tonight to the board. I found this thread on Google when searching Ampeg Gemini 1 amps.
    Looks like you're correct, the Gemini I had no ground reverse switch. I know the Gemini II did, as I've disabled a few of them myself.

    Years ago (I'm talking 1981 or so) I had a bitchin' brownface Fender Pro. (Gawd, I wish I still had it...back then, it was just an outdated amp to me.) Sometimes at rehearsals, the bass player would give me a sly look and I'd throw the polarity switch...we'd move up behind the singer and each touch a tuning key to opposite elbows and watch him jump out of his skin!

    Welcome to the board. We're a bunch of homebrewers, but we talk about all kinds of things...including cool old amps! How does that old Ampeg sound?

    EDIT: I should point out that the Gemini I DOES have a .05 uF cap between power and ground...it just doesn't have a switch to select which leg it's on. I'd still snip it out, but since your amp has a 3-prong plug, that's probably already been done.
    Last edited by BlindLemonLars; 10-19-2012 at 03:53 AM.
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