Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Oddvar on September 07, 2019, 03:31:18 am
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Hi people. I am a bit puzzled by this transformer, from a Hayden amp. Does 0-120v and 0-120v equal 240? The amp was made in Europe so I guess it must, but the amp is totally dead, so I thought I should check?
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0-120V (blu-gry) and 0-120V (red-brn) are tied in parallel for 120V mains: (blu+red tied together then to tied neutral) & (gry+brn tied together then tied to line) if the primaries are tied in series for 240V (gry+red tied together) blu ties to neutral & brown ties to line.
340V HV secondary is for a full wave bridge. the 13-0-13 is likely for bipolar power (+15 & -15V) supply to power op-amps. the 6.1V is for filaments. the G/Y is for shield and is grounded.
that PT can be confusing as there are three blu wires and three red wires. measure with a ohmmeter to be sure.
IF it's blown, you'll need to source another from the mfg., or have that unit repaired, or have a custom winder make you something similar. without the current ratings that will make thing a bit more difficult.
check each primary and secondary winding with an ohmmeter. 340V winding should measure around 100-200ohms. 0-120V windings should measure a few ohms; same for the 6.1V and 13-0-13 secondaries.
--pete
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Thanks Pete.