Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: mikhett on February 22, 2019, 12:53:42 pm

Title: Output transformer DC resistance measurements
Post by: mikhett on February 22, 2019, 12:53:42 pm

I have an output transformer from an 18 watt Ampeg vintage amp that I'm pulling parts from for a new amp build.I measured 97 ohms from red to blue on the primary and 87 ohms on red to brown.DOES THAT SEEM RIGHT?? THANKS

Title: Re: Output transformer DC resistance measurements
Post by: sluckey on February 22, 2019, 01:10:19 pm

That's probably right. You were expecting the resistances to be the same? Many times the primary is wound as two separate windings that are then joined together. The second half of the winding is wound on top of the first half and will require more/longer wire for the same number of turns.