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Rewinding a burned audio transformer, dying art

Posted: Thu Jul 02, 2026 5:00 am
by tito_elmer
Customer brought a 1972 Tagamatic tube amp. Output transformer burned. Replacement: discontinued. Modern equivalent: PHP 8000+ shipped.

Decided to rewind. Mga 3 weekends of evening work.

What it takes:
  • Carefully disassemble laminations (one bent lamination = lost mu)
  • Count primary and secondary turns as you unwind original (3,200 and 220 in this case)
  • Source 36AWG and 22AWG enamel wire (~PHP 800 spool)
  • Wind on lathe at 1 turn per second, count manually, takes 4 hours
  • Reassemble, vacuum-impregnate with varnish, bake at 60C overnight
Net cost: PHP 1100. Net time: 30 hours. Worth it for sentimental gear.

Hobby toroid transformer rewinders out there? Skill still teachable to younger folks?