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Hoffman Amps Forum image Author Topic: New builds  (Read 1831 times)

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Offline Bruce

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New builds
« on: January 04, 2018, 12:47:41 pm »
Just finished a Hoffman 5e3 build. I made with old power transformer from 1970 fender Deluxe reverb.it has the blue wire for bias tap. I want to use fixed bias with two pots.no cathode switch .i have  a other build 5e3 with cathode bias I made at the same time 1 Weber kit and 1 Hoffman kit ,I wanted to a-b them with different speakers to hear difference in the two builds .i know how to build two separate fixed bias supplies add the two pot ..Doi just sperate the two 220 r that go to ground and add bias to each resistor. Or is there something I am missing. Diagram would be helpful. And the fender transformer came in the picture after I blew the one that came with hoffmans kit ..totally my fault  I tried ss rectifying and voltages ran away cooked transformer. .and after a-b both builds for days I preferred Hoffman’s set up a little more than Weber’s ,and should have stoped messing with them ,but that’s how I school myself.but don’t want to fry my fender transformer  thanks allplease help

Offline EL34

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Re: New builds
« Reply #1 on: January 04, 2018, 12:50:49 pm »
Posted in wrong board - moved

Offline sluckey

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Re: New builds
« Reply #2 on: January 04, 2018, 01:11:56 pm »
Doi just sperate the two 220 r that go to ground and add bias to each resistor.
If you really mean 220K then yes.

Quote
Or is there something I am missing.
Yes there is one more thing. Connect the cathodes of the 6V6s directly to ground.
A schematic, layout, and hi-rez pics are very useful for troubleshooting your amp. Don't wait to be asked. JUST DO IT!

 


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