UTC 5946 (UA 175b, and 610a Transformer)

[Ian]

I am trying to find some info about the UTC 5946 Transformer for a UA 610 and 175B build I am trying to do. I can't seem to find any real information about this transformer. I've read that this transformer is essentially an A-19 wired in reverse, but I'm not sure if this is completely correct or not. I know that the drip website recommends a sowter transformer as a replacement in their build, but I'd really like to get the original (or at least some UTC/Triad equivalent) for my pre. If anyone has any information at all about this transformer (and any info about transformers used in the original 610a/175b and suitable substitutes) it would be GREATLY appreciated! Thanks!

 

[CJ]

this is as far as we got the last time round,

maybe we can improve our knowledge, let me ask doc hoyer if he has anything more...

do a search here on 610 and you get a bunch of hits also...

http://www.twin-x.com/groupdiy/albums/userpics/UA176-177-OutputXfmr.jpg

 

[Biasrocks]

I've read that this transformer is essentially an A-19 wired in reverse, but I'm not sure if this is completely correct or not.

Interested here as well. The A-19/A-18 was used as the interstage transformer, not as an output.

Mark

 

[CJ]

ok, this xfmr was made by

Electro-Engineering Works in San Leandro, CA.

but they,>Magnetica now, no longer have the winding information.

get a gapped  7:1 and you will be very close to the original.

the taps i do not know about.

back then, it was AM radio only, so bandwidth did not matter.

this is why Sowter says his is higher bandwidth, we "modernized" the design a bit.

slightly lower ratio, probably more interlayering than the original.

look at the UTC can size, guess at the core size,

 

[Ian]

Do you know what kind of cores these UTC transformers have? I think I might try to wind my own as an experiment. Is there 'go to' place for laminations, bobbins, wire etc needed to wind a good output transformer?

 

[CJ]

this will get you real close to the original>

 

[lassoharp]

In case you haven't come across these during your research:

http://www.groupdiy.com/index.php?topic=32729.0


http://www.groupdiy.com/index.php?topic=23825.0


B version PP as well?  A-24, A-26?

 

[CJ]

you need a bigger core than that i believe,

the stock core will take about 18 db for a dc  p- p xfmr.

i saw another version of this OPT that was a 7:1.

the core gets about 4 k gauss at 20 hz, so you can use a 50/50 alloy possibly?

 

[Bill Wilson]

Hi Guys: If any of you are interested I have 4 sets of UA transformers. One set is from a 1008 pre & the other 3 are from 1016's. The input transformers all look to be the same. The 1008used  a 12AY7 for theoutput& the 1016's could have a 12AX7/12AY7 for output if it was used as a mike pre/booster amp, or a 12BH7 as a line amplifier This is stamped on the transformers.

They came out of complete preamps. I had a client when I had my studio service co. in Nashville 79; he had aquired a console built with these UA amps. These were left over & I stripped the transformers off & discarded the pcb's & sheet metal last year. There was no hope for any of the old components & pcb's were made from cheap laminate. The 1016 circuit is balanced & should producea nice fat sound.

Thinking of putting these up on ebay unless someone here is interested.

 

[Biasrocks]

Hi Guys: If any of you are interested I have 4 sets of UA transformers. One set is from a 1008 pre & the other 3 are from 1016's.

Cool!

Definitely interested in a set Bill, I'm building a UA175 in the near future and it sounds like these would work perfectly.

If you'd like, we can continue by email, Mark [-@-] SharktankPro [-dot-] com

I send you a PM as well.

Mark

 

[mitsos]

interested in the 1008 output trafo... Are any of these a PA5946?

 

[JoleFIN]

Do you know what kind of cores these UTC transformers have? I think I might try to wind my own as an experiment. Is there 'go to' place for laminations, bobbins, wire etc needed to wind a good output transformer?

I'm interested of this too.. What's the most versatile place to order these in Europe? Any big differencies in prices between shops?

-J

 

[mitsos]

paging Dr CJ.... Ever take one of these apart??

 

[rafafredd]

Could anyone link to the BA2A schematic? I never seen it...

 

[rafafredd]

hmmm... Would that be the same as BA2C???