Vibro Champ mods for MOJO kits?

[Brad166]

Will the common mods that are done to older black and silver face Fender Vibro Champs apply to a Mojo Kit Vibro Champ?

Changing the bias cathode resistor from 470 to 1k watt and cap to 50uf/50v and putting 1k screen grid resistors are the mods im thinking of.

I know the bias mods are common because Fender started using Princton power trannys in the Champs. But are the modern MOJO kits featuring a corrected voltage or is it still to fender spec?

Thanks for any help

Brad

[Structo]

If this is a 5F1 Champ, they were designed back when the wall voltage was 110vac.

It's about a 8.7% difference.

You may know this.

So expect the B+ to be a bit above the designed or schematic voltage.
So if the amp was built for 110vac then the B+ should be about the same percentage as the 110vac.

I believe that a change from 470K to 1K will be a bit of a colder bias.
But you should always experiment with different values until the power tube either redplates or sounds gorgeous.

[Brad166]

Its a AA764 Vibro Champ

PT specs are

[Brad166]

I guess what I should say is..........Dose anyone know the B+ voltage on a original blackface AA764 power transformer?. Having trouble finding it on the internet.


Thanks guys

[Brad166]

Heh, im an idiot. They are maked on the fender layout...........

Sorry for the interruption...