Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Oddvar on August 12, 2019, 06:46:59 am

Title: Changing the Pt in Caliber 50
Post by: Oddvar on August 12, 2019, 06:46:59 am

Hi.  I am about to, hopefully, to change the transformer in a Mesa Caliber.50 from 117v Pt to a 230v one.  Could anyone here explain the drawing and the secondaries there to the color codes on the picture?  The heaters are self explanatory, the black and white also.  But the rest?

https://www.dropbox.com/s/p3rv4jrarihp5p1/Caliber%2050.png?dl=0
https://www.dropbox.com/s/1g2ougiu2zutypq/IMG_20190812_110928.jpg?dl=0

Title: Re: Changing the Pt in Caliber 50
Post by: sluckey on August 12, 2019, 07:20:40 am

The two reds are 350VAC. The red/yellow is a center tap and should connect to ground. The blue is 50VAC. This schematic is better. Page 4 is the power supply and explains everything.


     https://el34world.com/charts/Schematics/files/Mesa_boogie/Boogie_50cal.pdf


You will have to figure out how to wire the mains to the primary of your PT.

Title: Re: Changing the Pt in Caliber 50
Post by: Oddvar on August 12, 2019, 09:16:06 am

Thanks again Sluckey.  Any idea what kind of connector Mesa is using for connecting to the board?

Title: Re: Changing the Pt in Caliber 50
Post by: sluckey on August 12, 2019, 09:42:00 am

no