Merit A2904 OT help

[munkeyboy]

So I acquired a Silvertone 1482 at an amazing price.  Going thru and checking grounds, I found the output transformer barely hanging on due to the fact there was only one screw in it.  This due to it being an after market universal OT and the second hole was too far from the stock location.  Anyways, I drilled a hole and secured it, so that isn't the issue.   This issue is I have no idea how to wire taps for 8ohm (or 16ohm if possible) for a new speaker as there isn't much documentation for this transformer.  I don't even know that the taps are hooked up correctly for the stock speaker (4ohm).  However I did find this image.  Can someone explain how to work this chart to me like I'm an idiot?

[PRR]

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[tubenit]

PRR,   

THANKS for your continued help to all of us on the forum!  Your knowledge is remarkable and we all benefit from it. I appreciate your taking the time to give such useful and thoughtful explanations. I didn't know how to read & interpret that chart either.

Best regards & respect, Tubenit

[munkeyboy]

Thanks PRR!   

Totally makes sense now, not near as complex as I was thinking it to be.  You Rock!

[munkeyboy]

Odd.  The previous owner has this OT running off 1-2 to the (maybe) stock fisher speaker.   So if I read that right, that is ~1ohm.   Am I missing something?  Would this cause any audio problems (I have what sounds like a buzz at louder volumes)?


And just so I'm clear, to run the output at 4ohms, I would move the leads from 1&2 to 4&6 (3&6 for 8ohms and 1&6 for 16ish ohms)?

[sluckey]

The previous owner didn't know how to read the chart.

And just so I'm clear, to run the output at 4ohms, I would move the leads from 1&2 to 4&6 (3&6 for 8ohms and 1&6 for 16ish ohms)?

That's correct.

[munkeyboy]

The previous owner didn't know how to read the chart.

I can relate.  Thanks Sluckey!

[PRR]

Try it on 4&6.

Tube amps are tolerant, but a 4:1 slide may be some of your troubles.

4r on "8K:1" connection makes a 32K load. This will be down on power and clip abruptly.

[munkeyboy]

That works.   Buzz is still there, but thinking it's something loose in the chassis or a bad speaker.   Sounds good at mid volumes though.  Should be easy enough to pin point.

Thanks again guys!

[frankenxtein]

I realize this is a old post but , I think I just bought a couple Merit A2904's on eBay for $21.62 with shipping and tax. The seller shows two in the box. 
Often people come by stuff for a little bit of nothing and just make a quick sale.
Even if they only ship one transformer or only one works , I feel pretty lucky.
 I should stop searching for "Merit Transformer" on eBay probably but , if Merit was a lottery number. 

What puzzles me is how can a output transformer rated for 40ma , be a 18watt transformer?
Are they going by the single ended spec ? These are , universal output transformers.
I have a couple A2900's 35ma 4 watts and a A2901 40ma 8 watts.
The latter is still in my 12bh7 self split push pull , gonna change that out for one of the A2900's. One of these days.