PA521 ST70 Power Transformer for Dynaco 120v 240V Replacement for Dynaco MADE IN USA

New unit MADE IN USA by transformer professionals with decades of experience manufacturing high voltage transformers.

Improved replacement 240/120 volt dual primary export power transformer for Dynaco ST70. Heavier construction, runs cooler, gives better regulation, won't buzz & hum like some originals do. Bolts in to ST70. No modifications required, wires have identical color coding as the original unit. Extra long telfon insulated (instead of cheaper PVC) leads.

Also could be used to make a 70-90W mono power amp (depending on output tubes & rectifier) using the MQ-451-CL output transformer. Secondary B+ winding is 720VCT (360-0-360) at 300 ma with 55V bias tap, plus two 6.3VCT 5 amps & one 5V 4 amp tube filament & rectifier windings, and 55V bias tap.. Can use solid state rectifiers or any single tube rectifier with filament up to 5V at 4 amps (or 2 5AR4/GZ34 could be used in parallel) & sufficient B+ current rating....usually, 5AR4 or 5U4. (note, watch that the voltage isn't above capacitor ratings if solid-state rectifier is used!) Primary 240VAC or 120VAC 50/60 Hz. Mounts in 2 5/8 by 3 1/2 inch (67 X 90 mm) hole, mounting bolt pattern is 3 X 3 3/4 inches (77 X 96 mm). Nice long teflon insulated leads.


Wiring Diagram

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