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Post by crooktele79 on Nov 13, 2021 15:06:36 GMT -7
Hi all,
I just purchased a Galaxie head off of reverb. Went to hook hit up today for the first time and could get just a faint sound out of the amp. Then an increasingly loud hum began and the amp blew a fuse.
Could a bad rectifier tube be the culprit? The rectifier was really hot and you could smell an electrical odor for a few seconds afterward. The power tubes were cool to the touch however.
I’m thinking of ordering a full set of tubes, but am not opposed to sending it in to Doc for a checkup if that may be warranted.
Thanks
Chris
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Post by Chilly Gibbons (Todd T.) on Nov 13, 2021 15:31:35 GMT -7
The hum, then a blown fuse is a classic example of power tube failure. The fuse saved the transformer. The recto is likely okay, but the power tubes are toast.
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Post by Chilly Gibbons (Todd T.) on Nov 13, 2021 15:33:41 GMT -7
And for what it’s worth, I always retube any amp I get used. Well, let’s say I test the tubes in all used amps and usually end up replacing them.
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Post by Ridgeback on Nov 13, 2021 15:53:24 GMT -7
Don't forget to re-bias when replacing the rectifier or power tubes.
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Post by heynewguy (Ol’ Bill) on Nov 14, 2021 3:38:50 GMT -7
Doc told me if you order a medium rating power tube, chances are, you won’t have to re-bias. He also said if it sounds to hot, to turn it colder and vice versa. When I replaced the power tubes, it was perfect. What a difference the new 6L6’s made to the sound. Good luck with your Galaxy!
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Post by Ridgeback on Nov 14, 2021 6:11:05 GMT -7
I'd normally agree but on a new(used) amp that immediately blows fuse\tubes, I'd be checking the bias.
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Post by premiumplus (Dave) on Nov 14, 2021 14:44:43 GMT -7
I don't think you'll be needing preamp tubes, maybe just the phase inverter and a PAIR of matched, medium grade output tubes as Ol' Bill mentioned above. When you do turn it on and get it working please keep an eye on the output tube plates to be sure they don't start glowing a dull or brighter shade of red (red plating). If they do immediately turn the bias to a colder setting. I would expect you're probably pretty close unless somebody has been in there twiddling the bias pot. Do keep us posted, we're here to help. Congrats of a great amplifier, the Galaxie is a rockin' machine.
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Post by purpletele on Nov 14, 2021 17:02:31 GMT -7
I would plan on replacing the Rectifier to a NOS model at the same time. It has been my experience that the Rectifier goes when the event happens.
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Post by LT on Nov 15, 2021 13:45:04 GMT -7
I would plan on replacing the Rectifier to a NOS model at the same time. It has been my experience that the Rectifier goes when the event happens. Agree! I've replaced my rectifier tubes with NOS and haven't had an issue. I stick with the same type Doc recommends for each amp.
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Post by dcarver on Nov 15, 2021 17:18:29 GMT -7
Hi Crooktele79.
I think in your OP you said the rectifier got real hot and there was an electrical smell. Ummm you really need to have a spare. I wouldn't trust that thing.
I took the NOS 5AR4 path with my Maz 8. It really made the amp sound better. Stronger, more b@lls to it. It will probably last 10 years or more. Sometimes I wonder if some of the new production rectifiers are a little below spec. Anyway , good luck. Let us know how it works out.
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Post by crooktele79 on Nov 15, 2021 18:20:14 GMT -7
Thanks for all the replies everyone. Here’s where I am at. So it seems some doofus may have installed the power tubes incorrectly….shamefully, the doofus was me!
The rectifier did indeed go in the incident. I have a new one coming tomorrow. I stuck a new fuse in and reinstalled the power tubes correctly this time (oof). Powered the amp up, power tubes glowing, rectifier tube blown, but no signs of anything else and it did not blow the fuse this time. Will check it tomorrow with the new rectifier and go from there.
I am thinking of sending it in for the master volume mod and a full checkup regardless. Fingers crossed the only thing hurt is my pride at this point.
Chris
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Post by purpletele on Nov 15, 2021 19:11:35 GMT -7
Thanks for all the replies everyone. Here’s where I am at. So it seems some doofus may have installed the power tubes incorrectly….shamefully, the doofus was me! The rectifier did indeed go in the incident. I have a new one coming tomorrow. I stuck a new fuse in and reinstalled the power tubes correctly this time (oof). Powered the amp up, power tubes glowing, rectifier tube blown, but no signs of anything else and it did not blow the fuse this time. Will check it tomorrow with the new rectifier and go from there. I am thinking of sending it in for the master volume mod and a full checkup regardless. Fingers crossed the only thing hurt is my pride at this point. Chris Chris, We have all done Doofus things. I read through the events and it sounds like you are almost resolved. If the power tubes lit up then you shouldn't have had any collateral damage. You should be up and running with the new specified rectifier.
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Post by loucardguitar (Johnathan) on Nov 16, 2021 18:41:12 GMT -7
Sometimes I wonder if some of the new production rectifiers are a little below spec. Modern day tubes below spec??? NEVER!!! Ha!! Seriously though: OP - Glad it appears you have it taken care of!
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Post by pinkie on Nov 25, 2021 14:18:55 GMT -7
Do you have a Galaxie too? Which 6L6 brand you put in?
Doc told me if you order a medium rating power tube, chances are, you won’t have to re-bias. He also said if it sounds to hot, to turn it colder and vice versa. When I replaced the power tubes, it was perfect. What a difference the new 6L6’s made to the sound. Good luck with your Galaxy!
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Post by heynewguy (Ol’ Bill) on Nov 25, 2021 14:23:50 GMT -7
My son has one. He complained that it didn’t have the ummph that it used to. I tested the tubes, and the power tubes were bad. I ordered from the tube store in Canada that the Z website recommended. I’m not sure what tubes they were, but boy, what a difference it made! As always YMMV.
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Post by pinkie on Nov 25, 2021 14:59:53 GMT -7
Yes, power tubes make a difference, but if the power tubes are bad, the difference is bigger! I usually don't replace them to change the tone, because you have to re-bias, If I want to add a new flavour to my amp I prefer to change the V1 preamp tube.
I take this opportunity for a question: can you tell me if Bass and Treble controls work on both channels of the Galaxie?
My son has one. He complained that it didn’t have the ummph that it used to. I tested the tubes, and the power tubes were bad. I ordered from the tube store in Canada that the Z website recommended. I’m not sure what tubes they were, but boy, what a difference it made! As always YMMV.
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Post by heynewguy (Ol’ Bill) on Nov 25, 2021 17:28:10 GMT -7
Yes, power tubes make a difference, but if the power tubes are bad, the difference is bigger! I usually don't replace them to change the tone, because you have to re-bias, If I want to add a new flavour to my amp I prefer to change the V1 preamp tube.
I take this opportunity for a question: can you tell me if Bass and Treble controls work on both channels of the Galaxie?
My son has one. He complained that it didn’t have the ummph that it used to. I tested the tubes, and the power tubes were bad. I ordered from the tube store in Canada that the Z website recommended. I’m not sure what tubes they were, but boy, what a difference it made! As always YMMV. Like I said in the post above, it’s my son’s amp who now lives in Michigan.
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