Jensen JE-123 transformer hookup

Hello all. I have been reading stuff on this forum for a while, but this is my first posting.
I was wondering if someone can help me here with wiring my Jensen JE-123-A transformers. I have a pair of these 1970's transformers. Apparently they are the same configuration as  the new JT-123-ALCF transformers. I want to use them as 600:600 transformers on the output of a pair of Spectra Sonics 110 preamp cards. My understanding is that for best low frequencty response and performance when used as 1:1 trannies, the two primaries should be connected in series, and the two secondaries connected in series. I have added a link to the datasheet for the JT-123-ALCF transformers. Unfortunately my reading of circuit diagrams is pretty poor, so if someone can explain to me how to go about wiring these in the manner I described ( ie: what color wire goes where) I would be most grateful. The Spectra Sonics preamp has a + output feed which I want to balance via the Jensens to send to Xlr pins 2 and 3.

http://www.jensen-transformers.com/datashts/123alcf3.pdf

My guess is this is quadfilar like the API output.. if so, all 4 windings should have the same DCR.  Your idea to just put two windings in series for primary and the others in series for the secondary would be correct then.  According to the datasheet you posted, connect red to orange and blue to violet.  Now you have 2 windings in series for each, primary and secondary.

Next, connect the brown wire to the + output of the preamp, and the yellow to preamp ground.  Then, take the green to XLR pin 2, and the grey to pin 3.  Pin 1 goes to case, through a switch if you want to be able to lift the ground.

hth!

You can see the wiring in this data sheet: http://www.jensen-transformers.com/datashts/123slcf.pdf

You should add in X1 as well which came with the transformers (so I think if you got them off eBay) or buy direct from Jensen.

Regards, Ethan

Hey thanks guys. Much appreciated.........that's exactly the sort of info I was hoping for.

don't be afraid to contact jensen either. they are great with sharing technical information, even if you're not trying to buy something from them.

evm1024 said:

You can see the wiring in this data sheet: http://www.jensen-transformers.com/datashts/123slcf.pdf

You should add in X1 as well which came with the transformers (so I think if you got them off eBay) or buy direct from Jensen.

Regards, Ethan

Click to expand...

I see you recommend I use X1 ( Jensen JT-0LI-2 output load isolator). They didn't come with the transformers I got off ebay. These are 1970s transformers not new ones. I am going to rack the Spectra Sonics cards with input Triad input tansformers, and the Jensens on the output all in a 2 space rack chasis. Do I still need to use X1? I am not greatly experienced, and have limited knowledge so it's all on a learning curve for me here.

The short answer is stability. The long (and a great resource) is: http://www.groupdiy.com/index.php?topic=27550.0

--Ethan

PS I bout some je-123s off ebay and the seller included isolators.