Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: cavinccr on February 25, 2017, 10:59:22 am

Title: Kalamazoo Model 2 clone
Post by: cavinccr on February 25, 2017, 10:59:22 am

Hi all, I'm starting a Kal Model 2 clone build. I was going through the schematic that's readily available on the internet and I found something I don't understand. Voltage going into the 6X4 is 525vac but then after the rectifier it's 295v. How does it drop that much? Also I could use a power transformer recommendation. Thanks for any help. You guys are the best.

Title: Re: Kalamazoo Model 2 clone
Post by: sluckey on February 25, 2017, 11:15:19 am

That 525VAC is measured across the entire HT winding. It would only be 262.5VAC when measured in reference with the center tap. So, 262.5 is all the rectifier sees.

Hammond 270DAX would be my choice for power transformer. specs are 260-0-260 @ 90MA, 6.3V @ 4A.

     https://www.hammfg.com/files/parts/pdf/270DAX.pdf (https://www.hammfg.com/files/parts/pdf/270DAX.pdf)

Title: Re: Kalamazoo Model 2 clone
Post by: cavinccr on February 25, 2017, 01:45:43 pm

Thanks so much, as you can see I have a lot learn but I'm enjoying every bit of it..