Process for replacing transformer

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jasonallenh

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Joined
Dec 6, 2011
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Location
All Over Florida
I've got a headphone amp with an EI transformer that has some insane magnetostriction. The transformer has no markings to indicate any useful information. I've tried tightening it down, but it's still almost beginning to travel across my workbench. The unit works fine otherwise, but I'd prefer to drop a toroidal in it's place. I don't care if some hum gets into the audio line or anything like that- I'd rather my actual mix space be quiet and my musicians listen to the hum ;)

That being said, I disconnected the transformer. It's a CT secondary and each leg is at ~23V from the center tap, and 46.7ish volts away from the center tap. The amp has a 1amp fuse, so I'm assuming I don't need more than that from the secondary. Based on this and my own questionable educated guessing, I am led to believe this transformer should drop right in it's place-

http://www.mouser.com/ProductDetail/Hammond/1182K12/?qs=%2fha2pyFaduhLGMeoOSzIMdptrs0JOMq7ZnppQ7FwMbU%3d

How did I do? If I'm way off, could you please describe your process for determining a drop-in replacement? If it were any other component, I'd have no issues :p
 
> each leg is at ~23V from the center tap, and 46.7ish volts away from the center tap.

Unclear.

Hard to believe it takes 46V to smack headphones.
 
PRR said:
> each leg is at ~23V from the center tap, and 46.7ish volts away from the center tap.

Unclear.

Hard to believe it takes 46V to smack headphones.

This is a Furman Ha-6, which also drives up to two sets of speakers. With the DMM in AC measuring, It reads 23V from the leg to the center tap with the transformer disconnected. I have a schematic for a later version with +/-24VDC  after the PSU. This unit is very similar, but not the same.
 
It looks like you need a 24+24V transformer (or 48V center tapped) and you selected 12+12V or 24 center tapped.

From all that list in the datasheet maybe you could get away with 1182J22, it's 44V CT but all the 48VCT are way too big, I don't know what bitted those guys to start the  44V at 0.7A and the 48V ones at 10A  :eek:

You could also use two of the ones you selected, depends on the space you have to work with, sometimes 2 small transformers fits in a tighter space than a single big one.

JS
 
jasonallenh said:
Oh shoot... I thought 24V CT meant 24V per side...

...The search continues...

If you look closely it says series 24V parallel 12V. It's not center tapped but dual secondaries, that's ok of course as you can use it as CT without trouble.

JS
 
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