Woodward Schumacher 260:1 [2100 Ohms] Wollensak Revere 3M B131-5B Vintage Output Transformer OT Tested 90:1 25:1 Tube Amp Audio 1958-1962

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 1958-1962 by Woodward-Schumacher for Wollensak Revere 3M. 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 606023. Weighs 1 lbs 4 oz. Center-to-center bolt spacing is 60 mm, and height of casing is 59 mm. Quantity sometimes available - please enquire.

Using a 10V_pp, 1.00 kHz input to the primary coil, we have verified these connections for this vintage transformer:

The turns ratio (pri:sec) is 16:1, leading to an impedance ratio for the main secondary coil of 260:1. This winding of the transformer would provide a 2100 ohm load resistance to the tube plate if you hook it to an 8 Ohm speaker. n 8 ohm speaker.

This model has multiple secondary taps. Additional impedance ratios of 90:1 (via the orange-white connections), and 25:1 (via the orange-yellow connections) are available as options.

Primary is CT with red, agreeing with EIA color standards. Two isolated secondaries: Orange-yellow winding is CT with white.


SKU O-Wo5B.