Stancor 12559-1 Voice of Music Vintage Output Transformer OT Tested 625:1 135:1 400:1 Tube Amp Audio 1957-1961

One (1) fully 1.00 kHz AC tested and guaranteed vintage tube amp output transformer. AC testing using an oscilloscope allows us to find and reject transformers with noisy outputs, which a simple resistance or continuity test will not reveal. Made in USA in 1957-1961 by Stancor or Midwest for Voice of Music. IEA date code may vary, since this is a bulk listing of the OEM specification. Please offer $2 extra if you'd like us to poke through inventory to select a certain manufacturer or year. Otherwise, we'll grab the first one on the shelf. A typical IEA code for this model is 549840. Weighs 1 lbs 3 oz. Center-to-center bolt spacings 80 mm, and height of casing is 57 mm. Quantity sometimes available - please enquire.
This transformer was originally used to connect a 6L6 or 6V6 output tube to a 8 Ohm speaker.

Please see the image of an original schematic using this model, for one possible application!

Note: 1957 is out of stock.

Using a 12V_pp, 1.00 kHz input to the primary coil, we have verified these connections for this vintage transformer:

The turns ratio (pri:sec) is 25:1, leading to an impedance ratio for the main secondary coil of 625:1.This model has multiple secondary taps. Additional impedance ratios of 135:1 (via the black-green connections), and 400:1 (via the black-yellow connections), and are available as options.

Yellow and green are output winding. The black wire was used for cathode feedback, so this presents some flexibility. See schematic.


Serial number O-V559-1.