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Topic: Advice, please, about old 110v power transformer running hot |
Eric Philippsen
From:
Central Florida USA
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Posted 3 Jul 2017 6:28 am |
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I don't know the answer to this and was hoping someone could help.
I found an old (1954) Harmony H-20 Consolectric lap steel with a built-in amp in the case. The 3-tube amp is just a little thing - 5 watts at most. I replaced all the caps in it and checked everything else, It works fine now but its power transformer most definitely runs hot. I'm guessing that's because the wall voltage is around 122 while the amp was designed to run on 110 or so.
Short of using a Variac (which I have), is there an easy way modify the amp to see or get 110 volts? Put another way, is there any stepdown transformer, wal-wart, plug adaptor or that kind of thing that will do that?
Last, I know most older or vintage amps were built to see lower voltages. Now, most wall voltages are 120+. My experience is that it's usually not a problem but I'm guessing there is something made to help when 110 volts is desired.
Thanks in advance for your help. |
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Glenn Demichele
From:
(20mi N of) Chicago Illinois, USA
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Posted 3 Jul 2017 7:52 am
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You could put a light bulb in series with the power cord?
_________________
Franklin D10 8&5, Excel D10 8&5. Both amazing guitars! Homemade buffer/overdrive with adjustable 700Hz "Fender" scoop., Moyo pedal, GT-001 effects, 2x TDA7294 80W class AB amps, or 2x BAM200 for stereo. TT12 and BW1501 each in its own closed back wedge. Also NV400 etc. etc... |
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Scott Duckworth
From:
Etowah, TN Western Foothills of the Smokies
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Posted 3 Jul 2017 11:13 am
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A lot of time old transformer start to loose the coating and glue between the plates and start to vibrate, causing heat. May need to have the transformer rebuilt, or find a suitable replacement.
_________________
Amateur Radio Operator NA4IT (Extra)
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I may, in fact, be nuts. However, I am screwed onto the right bolt... Jesus! |
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Ivan Funk
From:
Hamburg Pennsylvania, USA
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Posted 3 Jul 2017 9:14 pm
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That sounds like a cool little machine.
Can you post pictures just for fun?
I had a small 5watt amp where the power transformer was getting hot. I checked the B+ coming off the rectifier tube and it was too high. I don't know why. I replaced the rectifier tube and everything went back to working properly. Every thing else checked out good too.
I'm guessing you amp has a 5Y3 for a rectifier.
Did you try new tubes?
Does the transformer buzz or hum when powered on with no tubes in it? |
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Lee Warren
From:
Nashville, Tennessee, USA
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