Tag Archives: UTC

UTC “R” Series universal replacement transformers of the 1940s/50s

UTC_r58_transformer_boxWhile searching through my output transformer shelf for a suitable reverb-driver transformer for the basket-case Kalamazoo Reverb 12 I recently rehab’d, I was glad to find this ancient NOS UTC R-58.   Inside the box was a near-disintegrated wiring sheet for the entire UTC ‘R’ line.  If you find yourself with any of the following units, here is what you need to know to implement it in your piece.  Apologies for the poor condition of the paper, this is the best we got!  INCLUDES: UTC R-27, R-28, R-38, R-38A, R-59, R-60, R-58 output transformers, UTC R1, R2, R3, R4, R5, R11, R12, R13, and R54 power transformers; and UTC R23, R24, R25, R26, R27, R28, and R29 ‘varitap’ interstage and input transformers.

DOWNLOAD A PDF: UTC R-SERIES TRANSFORMERS

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From the why-didn’t-i-think-of-that-first file – Great EZ hack for Octal can transformers

FirefoxScreenSnapz001Via this eBay auction: a UTC A-12 mounted on a plate-retained octal plug, with the pins wired to correspond to the pin-out of an Altec 4722 input transformer.

FirefoxScreenSnapz002It had simply never occurred to me that the mounting-diameter of a UTC A-series corresponded to the mounting-diameter of those octal-mount plates.   Well done sir.  Great idea if you have an Altec 1567, 1566, or ANY piece of old pro audio gear that uses octal transformers – and a great many do.  RCA, Newcomb, Ampex, the list goes on….