Wanted: Jensen JT-123-S or -H transformers, old Jensen datasheets

[skidmorebay]

Looking for these older, steel-core Jensen output transformers. Also, do anyone have datasheets for the JE-123-C or -A transformers?
thanks,
Justin

 

[TwentyTrees]

I have this handwritten note on the JE-123-A - seems to be the same handwriting as for the 123-S datasheet (also below, for reference). I love these old Jensen quadfilars, they're absolutely my output transformer of choice where possible. The "A" is physically quite a bit larger than the "S", though I don't have exact measurements.

 

[mjrippe]

How many do you need? I have some JE and JT 123-S that I could spare.

 

[JW]

I have a couple JE 123S transformers. Let me know what you're looking to pay for them and location. . . .

 

[skidmorebay]

Thanks for the replies! I guess I had notifications turned off for this thread, so I am just seeing these now. Awesome to have the datasheet, too. I think that may be Deane Jensen's handwriting...
I'll message each of you that have some transformers to sell.

 

[skidmorebay]

I have this handwritten note on the JE-123-A - seems to be the same handwriting as for the 123-S datasheet (also below, for reference). I love these old Jensen quadfilars, they're absolutely my output transformer of choice where possible. The "A" is physically quite a bit larger than the "S", though I don't have exact measurements.
View attachment 85539

View attachment 85540

Thanks, this is really helpful. I wish Jensen had an archive of these online.

 

[mjrippe]

Another fun scrap of info...though I think this has nickel in the core.

 

[MisterCMRR]

For reference, the model number "coding" for Jensen uses suffix "S" for steel, "L" for 50% nickel, and "M" for 80% nickel in its output transformer line. All input transformers use 80% nickel, a.k.a. "mu-metal" core material.

 

[MisterCMRR]

And the A, B, C, D, E, or F in the suffix refers to the core stack size, with A being the largest and F the smallest physical dimensions.

 

[Marcedona]

And the A, B, C, D, E, or F in the suffix refers to the core stack size, with A being the largest and F the smallest physical dimensions.

I wonder what JE and JT could stand for (just jensen-engineering, jensen-transformer, like this?), or the change could make any difference in sound or features?

 

[MisterCMRR]

Prior to his suicide in 1989, Deane's transformer designs were fabricated by Reichenbach Engineering and had a JE model prefix. There were ongoing financial and quality control problems - and no written contract - with Reichenbach. These were major factors in the suicide. He left the company to me in his will and I contracted fabrication with Jackson Engineering, changing to a JT model prefix. Low frequency performance (a function of design and core material) were unaffected, but unit-to-unit consistency (a function of winding uniformity) significantly improved.

Yes, that is Deane's handwriting on those early data sheets. One of the things I did in the early 90's was to standardize and expand on the transformer data sheets. Somewhere I have files of all those early data sheets. If I ever get my website up and running, I'll post them all ... but don't hold your breath!